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Introduction

Parkinson’s disease (PD) is a complex progressive neurodegenerative disorder influenced by a variety of genetic and environmental factors leading to its onset and advancement¹. The disease typically unfolds through two primary stages: early and advanced, each characterised by distinct symptomatic profiles and disease trajectories. Patients may experience subtle motor symptoms such as tremors, rigidity, bradykinesia, and postural instability in the early stages. These symptoms are usually well-treated and do not have a troublesome impact on daily life. However, as the disease progresses, motor disabilities may become overt and limit activities of daily living (ADLs). Patients may also notice a worsening in response to medications and later develop motor complications (such as wearing-off and dyskinesias) that may interfere with daily life^2,3.

In the early stages, patients typically manifest subtle motor symptoms, like impaired dexterity, which can impede their daily activities^{4, 5–6}. As PD progresses to the advanced stage, axial symptoms, mainly gait and postural abnormalities, emerge, leading individuals to curtail their mobility in basic daily tasks, professional responsibilities, and household chores^7,8. PD therapy predominantly emphasises symptomatic management to preserve patients’ functional capacities and overall quality of life. Consequently, evaluating the capacity to engage in ADLs amongst individuals with PD emerges as a crucial clinical outcome of effective symptomatic interventions⁹. ADLs can be segmented into self-ADLs, focusing on fundamental tasks like feeding, bathing, dressing, and mobility, and instrumental ADLs, comprising activities aiding independent living such as cooking, driving, and phone usage¹⁰. Nonetheless, developing a reliable tool that holistically assesses these two ADL categories from the patient’s perspective presents a significant challenge in clinical practice.

Presently, validated assessments of ADLs in PD predominantly rely on interviewer-administered tools rather than self-administered questionnaires. These assessments include parts 1 (non-motor experiences of daily living) and 2 (motor experiences of daily living) of the Movement Disorder Society-sponsored version of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), the Parkinson’s Disease Questionnaire-39 (PDQ-39), and the Schwab and England ADL scale. While these tools shed light on the repercussions of distinct PD symptoms on ADLs, they might not entirely encapsulate the holistic influence of the condition on day-to-day functionalities. For example, recent evaluations indicate that the MDS-UPDRS part 2 exhibits psychometric constraints that impede its accurate measurement of motor symptoms and their impact in early-stage PD¹¹. Although the PDQ-39 has undergone validation among PD patients and has proven acceptable and reliable, its application in clinical research is constrained by intricate item formulation, with ambiguity surrounding scale score interpretations posing challenges, impeding a clear and straightforward understanding during analysis and interpretation¹². While assessing motor functions from dependency to independence, the Schwab and England ADL scale neglects non-motor symptoms such as emotional well-being, cognitive abilities, and sexual function¹³.

Furthermore, these scales above often fail to establish a clear link between ADL performance and the progression of motor complications in PD patients. Despite the International Classification of Functioning, Disabilities, and Health (ICF) serving as the gold standard for evaluating daily function in neurological disorders, its lack of a tailored version for PD patients further hampers comprehensive assessment. While the ICF’s "Brief ICF Core Set for Hand Conditions" positively correlates with other PD-related scales, its capacity to capture all nuances of PD functionality remains questionable¹⁴. Additionally, the widely adopted Barthel and Katz indexes, designed for post-stroke patients and the elderly, offer diverse ADL assessments but do not cater specifically to the unique challenges faced by individuals with PD^15,16. In conclusion, these valuable instruments often exhibit shortcomings and are classified as merely “suggested” or “listed” tools for measuring ADLs in Parkinson’s disease¹⁷.

Our study aimed to develop and validate a multidimensional, self-administered questionnaire—the ChulaPD ADL—that comprehensively assesses the impact of PD on activities of daily living (ADLs), including in patients at various disease stages and those with motor complications. To our knowledge, no prior study has determined the effect of motor complications on ADLs in PD. The structured questionnaire was created and validated to explore the level of ADL limitations or disabilities and to identify the most common limitations faced by PD patients. Additionally, this questionnaire will be assessed for its validity and reliability in a cross-sectional study.

Method

Study design and participants

This single-centre, cross-sectional study was carried out at the outpatient movement disorders clinic of the Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders (ChulaPD, www.chulapd.org)¹⁸, located at King Chulalongkorn Memorial Hospital, spanning from August to December 2023. Ethical approval for this study was obtained from the Faculty of Medicine’s ethical committee at Chulalongkorn University (IRB No.134/62 and COA No.0776/2024). Information regarding this research study was provided and written informed consent was obtained from every subject at enrollment, in accordance with the declaration of Helsinki. A cohort of 231 participants (132 males and 99 females) diagnosed with Parkinson’s disease (PD) was randomly selected for inclusion in the research. Inclusion criteria included participants diagnosed with PD according to the UK Parkinson’s Disease Society Brain Bank criteria, aged ≥ 40 years, with Hoehn and Yahr stages 1–5. Exclusion criteria included the diagnosis of atypical parkinsonism, history of major psychiatric illness (e.g., schizophrenia), inability to complete the questionnaire due to severe dementia (MoCA less than 10 points), or language barriers. Detailed demographic information and pertinent health data including age, sex, disease duration, Montreal Cognitive Assessment (MoCA), Hoehn and Yahr score (H&Y), the total levodopa equivalent dose (LED), and The Unified Parkinson’s Disease Rating Scale (UPDRS scores—part 1,2,3, and 4) were gathered from each participant, following which they were requested to complete the ChulaPD ADL questionnaire, uniquely designed to evaluate the specific functional limitations in daily activities experienced by individuals with PD.

Questionnaire development

The ChulaPD ADL questionnaire used in this study was designed by neurologists specialising in movement disorders to measure the daily living activities and limitations of individuals with PD. The scale development and validation process followed best practices as outlined by Boateng et al. (2018), which provided a structured framework to enhance the methodological rigor and clarity of each stage¹⁹. This questionnaire was based on the functioning and disability domains from The International Classification of Functioning, Disability, and Health (ICF). It incorporated several daily living assessment questionnaires to comprehensively evaluate activities in PD patients, targeting 15 key aspects of daily life²⁰. The 15 aspects covered by the questionnaire were Feeding, Bladders/Toilet use, Bowels/Toilet use, Bathing/Shower, Dressing/Grooming, Dexterity, Mobility/Transfer/Stairs, Sleep (Motor), Sleep (Non-motor), Cognition, Mood/Emotion, Pain/Paresthesia/Discomfort, Communication, Sexual function, and Vision. By addressing these aspects of daily life, the questionnaire aimed to provide a comprehensive understanding of PD patients’ challenges and functional limitations, contributing valuable insights into their overall well-being and their need for assistance or environmental adaptations (Supplementary Data 1). The Chula PD ADL Questionnaire was administered to capture patients’ experiences over a typical day, encompassing both ON and OFF periods. When responding, patients were instructed to consider their functional ability across the full spectrum of their daily motor fluctuations. The questionnaire includes specific items that reflect activities likely to be impacted by symptom variability, ensuring that both improved and impaired periods are represented in the responses.

The former ChulaPD ADL questionnaire consisted of 135 items (15 items for grading limitation and 120 items for the ADL limitation questionnaire), each contributing to a detailed evaluation of the patient’s functional status. The questionnaire included the following scales:

Grading limitation scale: This scale consists of 15 items, each rated from 0 to 4 points, with a higher score indicating a greater degree of disability. The maximum score for the grading limitation scale is 60 points.
ADL limitation scale: This scale consists of four sections with 120 items. These sections are:
- Self-Limitation: Scores on a scale of 0 to 1, where 0 represents the absence of self-limitation, and 1 indicates the presence of self-limitation.
- Assistance Requirement and Environmental Limitations: Ranges from 0 to 1, where 0 denotes no requirement and no limitation, and 1 indicates the presence of both a requirement and a limitation.
- Consequence, Complication, and Psychosocial Interaction/Health Hazard: Ranges from 0 to 1, 0 denotes no relevance, and 1 indicates relevance.
- Effect of Motor Complications on Patient’s Daily Activities: Scores on a scale of 0 to 1, where 0 represents no effect of motor complications on daily activities, and 1 indicates the presence of daily disability due to motor complications.

Validation and reliability of the developed questionnaire

Content validity was assessed through the calculation of the item-objective congruence index (IOC). An expert panel comprising three movement disorders specialists and two PD nurse specialists evaluated the content validity. These professionals boasted extensive expertise in the field of PD in Thailand, demonstrated by a minimum of 10 years of clinical practice and scholarly contributions to international peer-reviewed publications. Across all items, the mean IOC value surpassed 0.6, signifying good content validation uniformly throughout the assessment. More details on content validation of the questionnaire at this stage were described in Supplementary Data 2.

The final decision to develop the ChulaPD ADL questionnaire hinged on its reliability gauged through a rigorous analysis employing two pivotal metrics with a pilot group comprising 30 patients diagnosed with PD. This statistical approach, leveraging correlation coefficient (R scores), initially scrutinised the linkage between individual questionnaire items and the overall assessment score, ensuring substantive contributions from each item. Furthermore, Cronbach’s Alpha aided in scrutinising the questionnaire’s internal consistency, facilitating identifying and eliminating items whose elimination bolstered the overall reliability and internal cohesion. Notably, the R scores for each ADL item surpassed 0.30, endorsing a moderate to strong positive linear relationship, thus affirming the questionnaire’s reliability across all 15 items. The corrected item-total correlation was used to choose and ensure that 115 items from the original 135-item questionnaire contributed meaningfully to the assessment (Table 1). This meticulous, analytical process sought to refine the questionnaire’s efficacy and precision in evaluating activities of daily living within the PD patient population. More details on validating the questionnaire at this stage are described in Supplementary Data 3.

Table 1. The process involved using the corrected item-total correlation to select and ensure that 115 items from the original 135-item ChulaPD ADL questionnaire contributed meaningfully to the assessment.

Items	Items of the former version of questionnaire		Items of a final version of questionnaire
Items	Grading limitation	ADL limitation	Grading limitation	ADL limitation
1. Feeding	1	9	1	6*
2. Bladders/ Toilet use	1	8	1	7*
3. Bowels/ Toilet use	1	6	1	6
4. Bathing/ Shower	1	5	1	3*
5. Dressing/ Grooming	1	6	1	4*
6. Dexterity	1	7	1	6*
7. Mobility/ Transfer/ Stairs	1	9	1	7*
8. Sleeping (Motor)	1	9	1	9
9. Sleeping (Non-motor)	1	10	1	9*
10. Cognition	1	10	1	8*
11. Mood/ Emotion	1	7	1	5*
12. Pain/ Paresthesia/ Discomfort	1	8	1	5*
13. Communication	1	8	1	8
14. Sexual function	1	9	1	9
15. Vision	1	9	1	8*
Total items	15	120	15	100
Total scores	60	120	60	100
Total ChulaPD ADL	135 items (180 scores)		115 items (160 scores)

ADL Activity of daily living.

The final version of the ChulaPD ADL questionnaire

The final version of the ChulaPD ADL questionnaire consisted of a total of 115 items, including 15 items for grading limitation and 100 items for the ADL limitation questionnaire (Supplementary data 1), each contributing to a detailed evaluation of the patient’s functional status. The 15 grading limitation items offer a minimum score of 0 points and a maximum score of 60 points, with a higher score indicating a greater limitation in performing ADLs in this section. Of the 100 items in the ADL limitation questionnaire, the breakdown is as follows: six items for feeding, seven items for bladders/toilet use, six items for bowels/toilet use, three items for bathing/showering, four items for dressing/grooming, six items for dexterity, seven items for mobility/transfer/stairs, nine items for sleep (motor), nine items for sleep (non-motor), eight items for cognition, five items for mood/emotion, five items for pain/paresthesia/discomfort, eight items for communication, nine items for sexual function, and eight items for vision. Each item offers a minimum score of 0 points to a maximum score of 1 point, resulting in a maximum possible score of 100 points for the ADL limitation questionnaire. A higher score in these sections indicates a greater limitation and relevant consequences for performing ADLs. Therefore, the total score of the final version of the ChulaPD ADL is 160 points. As part of the assessment protocol, participants completed the ChulaPD ADL Questionnaire alongside established clinical rating scales, including the Unified Parkinson’s Disease Rating Scale (UPDRS), the Montreal Cognitive Assessment (MoCA), and other patients’ demographics. Correlational analyses were conducted to examine the relationships between the ChulaPD ADL Questionnaire and these standardized measures to explore the extent to which the ChulaPD ADL Questionnaire captures overlapping or distinct aspects of functional and cognitive impairment in PD.

Sample size calculation

The sample size was determined based on standard recommendations for psychometric validation studies, particularly for exploratory factor analysis (EFA). A subject-to-item ratio of 5:1 to 10:1 is commonly cited as adequate for EFA. Given that the ChulaPD ADL questionnaire includes 16 items, a minimum of 160 participants was required based on a conservative 10:1 ratio. To ensure robustness, a larger sample was targeted. A total of 250 participants were initially enrolled in the study. After excluding 19 participants due to incomplete data or withdrawal (dropout rate: 7.6%), the final sample consisted of 231 participants, which exceeds the minimum requirement and provides sufficient statistical power for both EFA and ROC analyses.

Statistical analysis

All data are expressed as mean ± standard deviation for continuous variables and as proportions of patients (%) for categorical variables. The univariate analysis included the Student’s t-test and Chi-square test, as appropriate, to analyze differences between the two groups. A correlation analysis was conducted using Spearman’s method because most variables were ordinal in scale (such as the ChulaPD ADL scale and other scales). Correlation strength in this study was interpreted as follows: weak (0.10–0.39), moderate (0.40–0.69), strong (0.70–0.89), and very strong/perfect (> 0.90), based on Dancey and Reidy (2007). This provides clarity in interpreting the validation results²¹. Postural instability is a major contributor to functional decline and fall risk in PD; a quick ADL-based screening tool may help in early detection and intervention, especially in resource-limited settings.

For assessment of postural instability, postural instability was evaluated during the “on” medication state by trained movement disorder specialists as part of the clinical examination. It was not based on patient self-report. Instead, postural instability was assessed using the standardized “Pull Test,” which measures balance and postural control. This method is consistent with established clinical criteria for identifying significant postural instability in PD. To identify predictors that might determine postural instability, binary logistic regression analysis was undertaken in which the prevalence of postural instability was a dependent variable, and participant-related variables were selected to run into the logistic model as independent variables. The logistic model used the all forward (wald) method to choose the most predictable variables to determine postural instability, and the predictors were reported as odds ratios. Receiver operating characteristics (ROC) analysis was calculated for cutoff points for factors that might determine postural instability by determining sensitivity and specificity. The confidence interval was 95% for all analyses. The results of ROC analysis with a higher area under the curve values showed greater diagnostic accuracy for the possible predictive factors and included estimates of sensitivity and specificity. A p-value less than 0.05 (2-tailed) was considered statistically significant. All statistical analysis was performed using SPSS version 23.0 software. Moreover, to elaborate our understanding, we have developed figures utilising a radar chart format to illustrate the degree of functional limitation across different domains assessed by the ChulaPD ADL Questionnaire. This approach was chosen to facilitate a comparative, domain-level view of daily activity challenges in PD patients.

Result

Baseline characteristic of the study participants (Table 2, 3, 4, and Supplementary data 4)

Table 2. Summary of Demographic data and the mean score of ChulaPD ADL questionnaire from all 231 participants.

Item	Mean ± SD	Min–Max
Age (years)	67.73 ± 11.71	36–93
Disease duration (years)	11.74 ± 6.37	1–38
Hoehn and Yahr score	2.99 ± 1.23	1–5
Levodopa equivalent dosage (mg)	891.44 ± 567.66	112.5–3460
MoCA score	26.56 ± 3.59	14–30
UPDRS part 1 score	1.98 ± 1.87	0–10
UPDRS part 2 score	12.26 ± 6.88	1–30
UPDRS part 3 score	26.97 ± 14.45	4–60
UPDRS part 4 score	6.55 ± 5.38	0–20
UPDRS total score	47.76 ± 27.52	5–120
Sum score of grading limitation	19.93 ± 10.72	0–51
1. Sum feeding	1.32 ± 1.43	0–6
2. Sum bladders/Toilet use	1.85 ± 1.48	0–7
3. Sum bowels/Toilet use	2.32 ± 1.72	0–6
4. Sum bathing/Shower	1.03 ± 1.02	0–3
5. Sum dressing/Grooming	1.39 ± 1.44	0–4
6. Sum dexterity	2.18 ± 2.03	0–6
7. Sum mobility/Transfer/Stairs	3.65 ± 2.35	0–7
8. Sum sleeping (Motor)	3.45 ± 2.53	0–9
9. Sum sleeping (Non-motor)	4.28 ± 2.02	0–9
10. Sum cognition	2.71 ± 2.53	0–8
11. Sum mood/Emotion	1.75 ± 1.44	0–5
12. Sum pain/Paresthesia/Discomfort	1.82 ± 1.35	0–5
13. Sum communication	3.12 ± 2.54	0–8
14. Sum sexual function	1.84 ± 2.47	0–9
15. Sum vision	2.48 ± 2.19	0–8
Total ChulaPD ADL scores	55.13 ± 30.16	0–135

MoCA Montreal Cognitive Assessment, ADL Activity of daily living, LED Levodopa equivalent dosage, UPDRS Unified Parkinson’s Disease Rating Scale.

Table 3. Comparisons of the sum scores for the sum score of grading limitation and ADL limitation between patients according to disease severity by the Hoehn and Yahr scores.

Items	H&Y 1 N = 34	H&Y 2 N = 40	H&Y 3 N = 82	H&Y 4 N = 43	H&Y 5 N = 32	p-value
Items	Mean ± SD					p-value
Age	62.59 ± 10.59	62.05 ± 10.81	64.82 ± 9.69	74.35 ± 10.15	78.88 ± 9.13	< 0.001
Levodopa equivalent dosage	440.10 ± 155.53	660.04 ± 319.65	947.59 ± 578.00	1,084.84 ± 580.23	1,256.43 ± 567.66	< 0.001
1. Feeding
1.1 Grading of limitation	0.68 ± 0.73	0.63 ± 0.81	0.89 ± 0.79	1.65 ± 0.87	2.09 ± 1.09	< 0.001
1.2 Self limitation
Difficulty chewing/ Swallowing	0.24 ± 0.43	0.28 ± 0.45	0.40 ± 0.49	0.79 ± 0.41	0.75 ± 0.44	< 0.001
1.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.06 ± 0.24	0.08 ± 0.27	0.09 ± 0.28	0.37 ± 0.49	0.50 ± 0.51	< 0.001
Required food modification	0.15 ± 0.36	0.18 ± 0.38	0.21 ± 0.41	0.70 ± 0.46	0.72 ± 0.46	< 0.001
Using NG/ PEG	0.00	0.00	0.02 ± 0.15	0.02 ± 0.15	0.16 ± 0.37	0.001
1.4 Consequence, complication, and psychosocial interaction/Health hazard
Pneumonia, respiratory infection	0.06 ± 0.24	0.00	0.02 ± 0.15	0.05 ± 0.21	0.00	0.398
Malnutrition, dehydration, weight loss, low food intake	0.21 ± 0.41	0.10 ± 0.30	0.15 ± 0.36	0.40 ± 0.49	0.50 ± 0.51	< 0.001
2. Bladders/Toilet use
2.1 Grading of limitation	0.79 ± 0.84	1.08 ± 0.94	1.24 ± 0.82	1.86 ± 0.60	2.09 ± 1.00	< 0.001
2.2 Self limitation
Frequency/ Urgency	0.56 ± 0.50	0.60 ± 0.50	0.70 ± 0.46	0.81 ± 0.39	0.78 ± 0.42	0.071
Urinary incontinence/ Difficulty voiding	0.18 ± 0.39	0.23 ± 0.42	0.34 ± 0.48	0.40 ± 0.49	0.38 ± 0.49	0.157
2.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.15 ± 0.36	0.25 ± 0.44	0.28 ± 0.45	0.79 ± 0.41	0.69 ± 0.47	< 0.001
Need pampers	0.12 ± 0.33	0.20 ± 0.40	0.18 ± 0.45	0.37 ± 0.49	0.53 ± 0.51	< 0.001
Low water intake	0.03 ± 0.17	0.00	0.09 ± 0.28	0.16 ± 0.37	0.16 ± 0.37	0.035
2.4 Consequence, complication, and psychosocial interaction/Health hazard
Urinary tract infection	0.03 ± 0.17	0.05 ± 0.22	0.06 ± 0.24	0.09 ± 0.29	0.03 ± 0.18	0.741
Poor hygiene	0.00	0.05 ± 0.22	0.06 ± 0.24	0.05 ± 0.21	0.00	0.429
3. Bowels/Toilet use
3.1 Grading of limitation	1.09 ± 0.96	1.28 ± 0.90	1.48 ± 0.95	2.05 ± 0.61	1.78 ± 0.97	< 0.001
3.2 Self limitation
Straining/ Difficulty for defecation	0.21 ± 0.41	0.33 ± 0.47	0.51 ± 0.50	0.53 ± 0.50	0.50 ± 0.51	0.008
Lumpy/ Hard stools Incontinence	0.65 ± 0.48	0.53 ± 0.51	0.59 ± 0.50	0.86 ± 0.35	0.78 ± 0.42	0.004
3.3 Assistance requirement and environmental limitations
Manual maneuvers and less than 3 bowel movements per week	0.29 ± 0.46	0.28 ± 0.45	0.38 ± 0.49	0.70 ± 0.46	0.72 ± 0.46	< 0.001
Required laxative or detoxification	0.26 ± 0.45	0.28 ± 0.45	0.44 ± 0.50	0.56 ± 0.50	0.31 ± 0.47	0.023
3.4 Consequence, complication, and psychosocial interaction/Health hazard
Bowel complications (fecal impact, gut obstruction, hernia)	0.03 ± 0.17	0.03 ± 0.16	0.11 ± 0.31	0.19 ± 0.39	0.06 ± 0.25	0.060
3.5 During the time with motor fluctuations	0.21 ± 0.41	0.23 ± 0.42	0.34 ± 0.48	0.44 ± 0.50	0.09 ± 0.30	0.007
4. Bathing/Shower
4.1 Grading of limitation	0.35 ± 0.65	0.80 ± 1.04	0.74 ± 0.82	1.51 ± 0.80	1.75 ± 0.98	< 0.001
4.2 Self limitation
Difficulty body cleaning	0.03 ± 0.17	0.23 ± 0.42	0.15 ± 0.36	0.53 ± 0.50	0.63 ± 0.49	< 0.001
4.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.26 ± 0.45	0.43 ± 0.50	0.34 ± 0.48	0.79 ± 0.41	0.88 ± 0.34	< 0.001
4.4 Consequence, complication, and psychosocial interaction/Health hazard
Accident/ Falls	0.12 ± 0.33	0.23 ± 0.42	0.29 ± 0.46	0.35 ± 0.48	0.13 ± 0.34	0.057
5. Dressing/Grooming
5.1 Grading of limitation	0.50 ± 0.90	0.83 ± 0.90	0.84 ± 0.87	1.77 ± 0.84	2.06 ± 1.01	< 0.001
5.2 Self limitation
Difficulty dressing	0.21 ± 0.41	0.33 ± 0.47	0.38 ± 0.49	0.56 ± 0.50	0.69 ± 0.47	< 0.001
Difficulty grooming/ Make up	0.18 ± 0.39	0.28 ± 0.45	0.21 ± 0.41	0.70 ± 0.46	0.81 ± 0.40	< 0.001
5.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.24 ± 0.43	0.30 ± 0.46	0.23 ± 0.42	0.74 ± 0.44	0.84 ± 0.37	< 0.001
5.4 Consequence, complication, and psychosocial interaction/Health hazard
Social isolation/ Avoidance	0.09 ± 0.29	0.18 ± 0.38	0.16 ± 0.37	0.23 ± 0.43	0.13 ± 0.34	0.507
6. Dexterity
6.1 Grading of limitation	0.71 ± 0.84	0.95 ± 0.99	1.17 ± 0.94	1.86 ± 1.01	2.19 ± 0.82	< 0.001
6.2 Self limitation
Dexterity to self ADL (brushing teeth, washing hand, wearing mask)	0.15 ± 0.36	0.18 ± 0.38	0.27 ± 0.45	0.33 ± 0.47	0.31 ± 0.47	0.268
Dexterity to instrumental ADL (eating, using telephone, using computer, writing)	0.32 ± 0.47	0.43 ± 0.50	0.50 ± 0.50	0.81 ± 0.39	0.88 ± 0.34	< 0.001
Dexterity to environment (open the door, turning the light on)	0.15 ± 0.36	0.23 ± 0.42	0.21 ± 0.41	0.26 ± 0.44	0.34 ± 0.48	0.401
6.3 Assistance requirement and environmental limitations
Limit social activities	0.24 ± 0.43	0.33 ± 0.47	0.34 ± 0.48	0.56 ± 0.50	0.72 ± 0.46	< 0.001
Need assistance/ Assistive devices	0.35 ± 0.48	0.33 ± 0.47	0.33 ± 0.47	0.70 ± 0.46	0.84 ± 0.37	< 0.001
6.4 Consequence, complication, and psychosocial interaction/Health hazard
Losing career opportunity	0.12 ± 0.33	0.25 ± 0.44	0.23 ± 0.42	0.33 ± 0.47	0.28 ± 0.46	0.309
7. Mobility/Transfer/Stairs
7.1 Grading of limitation	0.85 ± 0.92	1.33 ± 1.00	1.68 ± 0.86	2.28 ± 0.91	2.59 ± 0.83	< 0.001
7.2 Self limitation
Walking	0.56 ± 0.50	0.68 ± 0.47	0.83 ± 0.38	0.95 ± 0.21	0.94 ± 0.25	< 0.001
Using transportation	0.35 ± 0.48	0.38 ± 0.49	0.37 ± 0.48	0.67 ± 0.47	0.75 ± 0.44	< 0.001
Driving	0.26 ± 0.45	0.40 ± 0.50	0.49 ± 0.50	0.65 ± 0.48	0.72 ± 0.46	0.001
7.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.44 ± 0.50	0.58 ± 0.50	0.60 ± 0.49	0.86 ± 0.35	0.88 ± 0.34	< 0.001
Environmental modification	0.18 ± 0.39	0.38 ± 0.49	0.28 ± 0.45	0.67 ± 0.47	0.53 ± 0.51	< 0.001
7.4 Consequence, complication, and psychosocial interaction/Health hazard
Losing career opportunity	0.09 ± 0.29	0.33 ± 0.47	0.29 ± 0.46	0.37 ± 0.49	0.56 ± 0.50	0.001
Limit social activities	0.26 ± 0.45	0.38 ± 0.49	0.74 ± 0.50	0.74 ± 0.44	0.75 ± 0.44	< 0.001
8. Sleeping (Motor)
8.1 Grading of limitation	0.85 ± 0.82	1.33 ± 0.89	1.39 ± 0.90	1.86 ± 0.74	2.06 ± 0.88	< 0.001
8.2 Self-limitation
Getting out of bed/ Bed turning	0.06 ± 0.24	0.15 ± 0.36	0.39 ± 0.49	0.65 ± 0.48	0.69 ± 0.47	< 0.001
Complex nocturnal behavior/ Dream enactment	0.41 ± 0.50	0.48 ± 0.51	0.55 ± 0.50	0.58 ± 0.50	0.53 ± 0.51	0.587
Simple sleep-related movement	0.41 ± 0.50	0.58 ± 0.50	0.51 ± 0.50	0.77 ± 0.43	0.69 ± 0.47	0.010
8.3 Assistance requirement and environmental limitations
Need assistance/ Assistive devices	0.12 ± 0.33	0.28 ± 0.45	0.29 ± 0.46	0.33 ± 0.47	0.44 ± 0.50	0.072
8.4 Consequence, complication, and psychosocial interaction/Health hazard
Impaired sleep performance	0.35 ± 0.48	0.40 ± 0.50	0.50 ± 0.50	0.65 ± 0.48	0.66 ± 0.48	0.021
Nocturnal injury	0.00	0.05 ± 0.22	0.09 ± 0.28	0.19 ± 0.39	0.16 ± 0.37	0.038
Impaired getting out of bed	0.32 ± 0.47	0.35 ± 0.48	0.33 ± 0.47	0.42 ± 0.50	0.59 ± 0.50	0.095
Poor caregiver’s sleep quality	0.12 ± 0.33	0.28 ± 0.45	0.27 ± 0.45	0.33 ± 0.47	0.34 ± 0.48	0.235
8.5 During the time with motor fluctuations	0.35 ± 0.48	0.33 ± 0.47	0.43 ± 0.50	0.56 ± 0.50	0.31 ± 0.47	0.141
9. Sleeping (Non-motor)
9.1 Grading of limitation	1.21 ± 0.69	1.55 ± 0.68	1.62 ± 0.76	2.05 ± 0.72	2.38 ± 0.66	< 0.001
9.2 Self limitation
Sleep continuity (insomnia)	0.32 ± 0.47	0.38 ± 049	0.80 ± 0.40	0.88 ± 0.32	0.94 ± 0.25	< 0.001
Nocturia	0.53 ± 0.51	0.55 ± 0.50	0.66 ± 0.48	0.86 ± 0.35	0.91 ± 0.30	< 0.001
Nocturnal pain	0.24 ± 0.43	0.35 ± 0.48	0.33 ± 0.47	0.37 ± 0.49	0.16 ± 0.37	0.229
Snoring or sleep breathing disorder	0.35 ± 0.48	0.35 ± 0.48	0.49 ± 0.50	0.23 ± 0.43	0.28 ± 0.46	0.048
9.3 Assistance requirement and environmental limitations
Need sleeping medication	0.12 ± 0.33	0.23 ± 0.42	0.35 ± 0.48	0.33 ± 0.47	0.19 ± 0.40	0.057
Need PAP device	0.06 ± 0.24	0.05 ± 0.22	0.10 ± 0.30	0.07 ± 0.26	0.09 ± 0.30	0.881
9.4 Consequence, complication, and psychosocial interaction/Health hazard
Impaired sleep performance	0.56 ± 0.50	0.45 ± 0.50	0.46 ± 0.50	0.72 ± 0.45	0.63 ± 00.49	0.042
Daytime somnolence	0.79 ± 0.41	0.85 ± 0.36	0.79 ± 0.41	0.84 ± 0.37	0.97 ± 0.18	0.224
9.5 During the time with motor fluctuations	0.47 ± 0.51	0.38 ± 0.49	0.55 ± 0.50	0.56 ± 0.50	0.44 ± 0.50	0.354
10. Cognition
10.1 Grading of limitation	0.62 ± 0.82	0.93 ± 0.92	1.15 ± 0.98	1.86 ± 0.99	2.00 ± 0.88	< 0.001
10.2 Self limitation
Impaired attention/ Memory	0.15 ± 0.36	0.40 ± 0.50	0.46 ± 0.50	0.72 ± 0.45	0.72 ± 0.46	< 0.001
Impaired executive function	0.24 ± 0.43	0.38 ± 0.49	0.35 ± 0.48	0.56 ± 0.50	0.75 ± 0.44	< 0.001
10.3 Assistance requirement and environmental limitations
Impaired solving problems	0.12 ± 0.33	0.33 ± 0.47	0.24 ± 0.43	0.37 ± 0.49	0.53 ± 0.51	0.003
Impaired undertaking tasks	0.32 ± 0.47	0.48 ± 0.51	0.29 ± 0.46	0.72 ± 0.45	0.69 ± 0.47	< 0.001
Need assistance/ Supervision	0.21 ± 0.41	0.33 ± 0.47	0.30 ± 0.46	0.56 ± 0.50	0.78 ± 0.42	< 0.001
10.4 Consequence, complication, and psychosocial interaction/Health hazard
Social avoidance	0.21 ± 0.41	0.15 ± 0.36	0.22 ± 0.42	0.42 ± 0.50	0.41 ± 0.50	0.013
Losing career opportunity	0.12 ± 0.33	0.30 ± 0.46	0.26 ± 0.44	0.30 ± 0.46	0.34 ± 0.48	0.250
Harm to self or others	0.00	0.05 ± 0.22	0.11 ± 0.31	0.12 ± 0.32	0.06 ± 0.25	0.247
11. Mood/Emotion
11.1 Grading of limitation	1.00 ± 0.82	1.10 ± 0.84	1.23 ± 0.82	1.63 ± 0.76	1.56 ± 0.67	0.001
11.2 Self limitation
Anxiety/ Irritability	0.68 ± 0.47	0.63 ± 0.49	0.70 ± 0.46	0.88 ± 0.32	0.84 ± 0.37	0.031
Depression/ Anhedonia	0.24 ± 0.43	0.23 ± 0.42	0.28 ± 0.45	0.30 ± 0.46	0.16 ± 0.37	0.615
Impulsivity	0.26 ± 0.45	0.33 ± 0.47	0.34 ± 0.48	0.49 ± 0.51	0.13 ± 0.34	0.019
11.3 Assistance requirement and environmental limitations
–	–	–	–	–	–	–
11.4 Consequence, complication, and psychosocial interaction/Health hazard
Poor family relationship	0.12 ± 0.33	0.15 ± 0.36	0.13 ± 0.34	0.14 ± 0.35	0.09 ± 0.30	0.963
11.5 During the time with motor fluctuations	0.38 ± 0.49	0.30 ± 0.46	0.32 ± 0.47	0.35 ± 0.48	0.19 ± 0.40	0.498
12. Pain/Paresthesia/Discomfort
12.1 Grading of limitation	1.03 ± 0.80	1.05 ± 0.85	1.20 ± 0.87	1.56 ± 0.73	1.91 ± 0.78	< 0.001
12.2 Self limitation
Musculoskeletal pain	0.68 ± 0.47	0.70 ± 0.46	0.70 ± 0.46	0.88 ± 0.32	0.84 ± 0.37	0.078
Orofacial pain	0.18 ± 0.39	0.08 ± 0.27	0.16 ± 0.37	0.28 ± 0.45	0.31 ± 0.47	0.053
12.3 Assistance requirement and environmental limitations
Limit activities	0.15 ± 0.36	0.33 ± 0.47	0.24 ± 0.43	0.49 ± 0.51	0.41 ± 0.50	0.008
Require treatment/ Intervention	0.32 ± 0.47	0.40 ± 0.50	0.35 ± 0.48	0.63 ± 0.49	0.56 ± 0.50	0.012
12.4 Consequence, complication, and psychosocial interaction/Health hazard
Poly pharmacy; painkillers, antidepressants, gabapentin, etc	0.06 ± 0.24	0.15 ± 0.36	0.13 ± 0.34	0.16 ± 0.37	0.16 ± 0.37	0.707
13. Communication
13.1 Grading of limitation	0.88 ± 0.98	1.25 ± 0.90	1.41 ± 0.95	1.98 ± 0.64	2.19 ± 0.93	< 0.001
13.2 Self limitation
Hypophonia	0.62 ± 0.49	0.70 ± 0.46	0.68 ± 0.47	0.95 ± 0.21	0.88 ± 0.34	0.001
Stuttering	0.2 ± 0.47	0.48 ± 0.51	0.46 ± 0.50	0.51 ± 0.51	0.41 ± 0.50	0.521
Difficulty in communication skills	0.21 ± 0.41	0.35 ± 0.48	0.41 ± 0.50	0.60 ± 0.49	0.75 ± 0.44	< 0.001
13.3 Assistance requirement and environmental limitations
Difficult understanding	0.12 ± 0.33	0.25 ± 0.44	0.29 ± 0.46	0.44 ± 0.50	0.22 ± 0.42	0.026
Need assistance/ Assistive devices	0.15 ± 0.36	0.30 ± 0.46	0.28 ± 0.45	0.53 ± 0.50	0.59 ± 0.50	< 0.001
13.4 Consequence, complication, and psychosocial interaction/Health hazard
Social isolation/ Avoidance	0.18 ± 0.39	0.15 ± 0.36	0.24 ± 0.43	0.33 ± 0.47	0.19 ± 0.40	0.327
Effect on mood	0.32 ± 0.47	0.30 ± 0.46	0.28 ± 0.45	0.44 ± 0.50	0.25 ± 0.44	0.367
13.5 During the time with motor fluctuations	0.32 ± 0.47	0.30 ± 0.46	0.29 ± 0.46	0.30 ± 0.46	0.25 ± 0.44	0.978
14. Sexual function
14.1 Grading of limitation	0.29 ± 0.68	0.58 ± 0.93	0.71 ± 0.97	1.23 ± 1.06	1.81 ± 1.15	< 0.001
14.2 Self limitation
Impaired sexual drive/ Arousal/ Loss of libido	0.15 ± 0.36	0.25 ± 0.44	0.26 ± 0.44	0.49 ± 0.51	0.72 ± 0.46	< 0.001
Impaired erection/ Moist	0.15 ± 0.36	0.28 ± 0.45	0.23 ± 0.42	0.51 ± 0.51	0.72 ± 0.46	< 0.001
Impaired reaching orgasm	0.06 ± 0.24	0.23 ± 0.42	0.16 ± 0.37	0.16 ± 0.37	0.25 ± 0.44	0.251
Hypersexuality	0.06 ± 0.24	0.08 ± 0.27	0.07 ± 0.26	0.05 ± 0.21	0.19 ± 0.40	0.218
14.3 Assistance requirement and environmental limitations
Require non-pharmacological or pharmacological intervention/ Treatment	0.18 ± 0.39	0.20 ± 0.40	0.11 ± 0.31	0.14 ± 0.35	0.22 ± 0.42	0.551
14.4 Consequence, complication, and psychosocial interaction/Health hazard
Impaired intimate relationships	0.09 ± 0.29	0.18 ± 0.35	0.20 ± 0.40	0.30 ± 0.46	0.34 ± 0.48	0.065
Effect on mood	0.18 ± 0.39	0.18 ± 0.38	0.18 ± 0.39	0.21 ± 0.41	0.16 ± 0.37	0.985
Decreased or unsatisfied sexual activities	0.09 ± 0.29	0.23 ± 0.42	0.16 ± 0.37	0.21 ± 0.41	0.34 ± 0.48	0.093
14.5 During the time with motor fluctuations	0.09 ± 0.29	0.20 ± 0.40	0.15 ± 0.36	0.21 ± 0.41	0.06 ± 0.25	0.293
15. Vision
15.1 Grading of limitation	0.88 ± 0.84	0.85 ± 0.83	1.15 ± 0.89	1.58 ± 0.79	1.78 ± 0.83	< 0.001
15.2 Self limitation
Impaired distance activities	0.29 ± 0.46	0.33 ± 0.47	0.41 ± 0.50	0.70 ± 0.46	0.66 ± 0.48	< 0.001
Impaired peripheral vision	0.18 ± 0.39	0.25 ± 0.44	0.21 ± 0.41	0.26 ± 0.44	0.19 ± 0.40	0.885
Dry eyes	0.44 ± 0.50	0.58 ± 0.50	0.61 ± 0.49	0.72 ± 0.45	0.81 ± 0.40	0.017
15.3 Assistance requirement and environmental limitations
Require non-pharmacological or pharmacological intervention/ Treatment	0.26 ± 0.45	0.33 ± 0.46	0.30 ± 0.46	0.49 ± 0.51	0.69 ± 0.47	0.001
Need assistant/ Assistive device (instrumental ADL device)	0.15 ± 0.36	0.23 ± 0.42	0.23 ± 0.42	0.37 ± 0.49	0.31 ± 0.47	0.189
15.4 Consequence, complication, and psychosocial interaction/Health hazard
Avoid social activities	0.09 ± 0.29	0.15 ± 0.36	0.15 ± 0.36	0.16 ± 0.37	0.09 ± 0.30	0.820
Accidents and injuries	0.03 ± 0.17	0.15 ± 0.36	0.23 ± 0.42	0.30 ± 0.46	0.09 ± 0.30	0.011
15.5 During the time with motor fluctuations	0.15 ± 0.36	0.20 ± 0.40	0.24 ± 0.43	0.23 ± 0.43	0.16 ± 0.37	0.722

Table 4. Comparisons of the sum scores for the sum score of grading limitation and ADL limitation between patients with and without postural instability.

Items	No postural instability N = 75	Postural instability N = 156	p-value
Items	Mean ± SD		p-value
Age (years)	62.29 ± 10.56	70.35 ± 11.35	< 0.001
Disease duration (years)	10.95 ± 5.64	12.13 ± 6.68	0.187
Hoehn and Yahr score	1.57 ± 0.57	3.68 ± 0.79	< 0.001
Levodopa equivalent dosage (mg)	559.53 ± 276.89	1051.00 ± 602.18	< 0.001
MoCA score	29.13 ± 0.99	25.33 ± 3.73	< 0.001
UPDRS part 1 score	0.80 ± 1.065	2.55 ± 1.92	< 0.001
UPDRS part 2 score	5.67 ± 3.28	15.44 ± 5.82	< 0.001
UPDRS part 3 score	12.57 ± 5.82	33.88 ± 12.053	< 0.001
UPDRS part 4 score	0.95 ± 1.94	9.24 ± 4.317	< 0.001
UPDRS total score	19.99 ± 10.95	61.12 ± 22.67	< 0.001
Sum score of grading LIMITATION	13.80 ± 9.85	22.88 ± 9.86	< 0.001
1. Sum feeding	0.68 ± 1.04	1.63 ± 1.48	< 0.001
2. Sum bladders/Toilet use	1.21 ± 1.31	2.16 ± 1.46	< 0.001
3. Sum bowels/Toilet use	1.64 ± 1.49	2.65 ± 1.72	< 0.001
4. Sum bathing/Shower	0.68 ± 1.00	1.19 ± 1.00	< 0.001
5. Sum dressing/Grooming	0.89 ± 1.39	1.63 ± 1.41	< 0.001
6. Sum dexterity	1.52 ± 1.99	2.50 ± 1.97	0.001
7. Sum mobility/Transfer/Stairs	2.65 ± 2.47	4.13 ± 2.13	< 0.001
8. Sum sleeping (Motor)	2.51 ± 2.41	3.90 ± 2.46	< 0.001
9. Sum sleeping (Non-motor)	3.50 ± 2.01	4.65 ± 1.92	< 0.001
10. Sum cognition	1.89 ± 2.36	3.10 ± 2.52	0.001
11. Sum mood/Emotion	1.63 ± 1.46	1.81 ± 1.43	0.355
12. Sum pain/Paresthesia/Discomfort	1.51 ± 1.29	1.97 ± 1.35	0.013
13. Sum communication	2.56 ± 2.58	3.39 ± 2.48	0.019
14. Sum sexual function	1.43 ± 2.46	2.04 ± 2.45	0.078
15. Sum vision	1.92 ± 2.20	2.75 ± 2.14	0.007
Total ChulaPD ADL scores	40.01 ± 30.28	62.40 ± 27.35	< 0.001

The statistical analysis was performed using an unpaired t-test, p < 0.05 indicating statistical significance; MoCA Montreal Cognitive Assessment, ADL: Activity of daily living, LED Levodopa equivalent dosage, UPDRS Unified Parkinson’s Disease Rating Scale.

A total of 231 participants (132 males (57.1%) and 99 females (42.9%)) responded to the questionnaire. The mean age was 67.73 ± 11.70 years, and the mean disease severity, according to the H&Y score, was 2.99 ± 1.23 points (Table 2 and Supplementary data 4). Of the 231 participants, 34 (14.7%) were at H&Y stage 1, 40 (17.3%) were at H&Y stage 2, 82 (35.5%) were at H&Y stage 3, 43 (18.6%) were at H&Y stage 4, and 32 (13.9%) were at H&Y stage 5 (Table 3). Furthermore, 157 (68%) of all participants noticed problems with postural instability (Table 4). The mean levodopa equivalent dosage was 891.43 ± 567.66 mg per day. This study found a statistically significant increase in age correlated with the H&Y score, where there was a slight increase in age associated with more advanced H&Y stages. At H&Y stages 1–3, the mean patient age ranged from 62.05 to 64.82 years, while at more advanced stages (H&Y 4–5), the mean patient age was between 74.35 and 78.88 years. Additionally, there was a statistically significant increase in LED according to the H&Y score, with a slight rise in LED associated with more advanced H&Y stages. At H&Y stages 1–3, the mean LED ranged from 440.10 to 947.59 mg per day, but at the more advanced stages (H&Y 4–5), the mean LED ranged from 1,084.84 to 1,256.43 mg per day (Table 3).

Comparison in the result from the screening questionnaire for the sum score of grading limitation and sum score of ADL limitations according to patient’s severity (Table 4)

This study found a statistically significant increase in the sum score of grading limitation based on an increase in the H&Y score. From the sum score of grading limitation, the mean score of patients with H&Y stage 1 is 11.73 ± 9.64 points, H&Y stage 2 is 15.50 ± 9.94 points, H&Y stage 3 is 17.90 ± 8.06 points, H&Y stage 4 is 26.72 ± 7.67 points, and H&Y stage 5 is 30.25 ± 9.81 points. In addition, this study found a statistically significant difference in the sum scores of grading limitation between patients with or without postural instability (Table 4); patients with postural instability show significantly higher sum scores than patients without postural instability (22.88 ± 9.86 vs 13.80 ± 9.85, p < 0.001), and also considerably higher in following sections; feeding, bladders/toilet use, bowels/toilet use, bathing/shower, dressing/grooming, dexterity, mobility/transfer/stairs, sleep (motor), sleep (non-motor), cognition, pain/paresthesia/discomfort, communication, and vision (p < 0.05, each). Moreover, the statistically significant difference in total ChulaPD ADL scores between patients with or without postural instability (Table 4), by patients with postural instability show significantly higher sum scores than patients without postural instability (62.40 ± 27.35 vs 40.01 ± 30.28, p < 0.001).

Details for grading and ADL limitation according to the H&Y score (Table 3)

This study showed a slight increase in grading limitations score for each item in all 15 key aspects of daily life activities associated with more advanced H&Y stages (Table 3). Additionally, a slight increase in assistance requirement and environmental limitations was found in most activities as the H&Y advanced (p < 0.05), except for sleep (motor), pain/paresthesia/discomfort, mood/emotion, and sexual function. Moreover, the section related to consequence, complication, and psychosocial interaction/health hazard was found to be more affected in advanced H&Y stages in certain activities, including feeding, mobility/transfer/stairs, sleep (motor), mood/emotion, pain/paresthesia/discomfort, and sexual function (p < 0.05 for each). Furthermore, regarding the effect of activity limitation during periods of motor fluctuations, only bowel/toilet use was reported by patients to show more limitation in a more advanced stage of the disease (p = 0.007).

Correlation of the ChulaPD ADL questionnaire score and patients’ demographic and clinical rating scales, including H&Y, MoCA, and UPDRS score (Tables 5 and 6)

Table 5. Spearman’s correlation between the ChulaPD ADL score, Patients’ demographics, and Clinical rating scales.

Items	Age	Disease duration	H&Y	LED	MoCA	UPDRS1	UPDRS2	UPDRS3	UPDRS4	Total UPDRS	Sum score of grading limitation	Total ChulaPD ADL score
Sum score of grading limitation	0.479*	0.193*	0.558*	0.360*	− 0.523*	0.372*	0.544*	0.547*	0.550*	0.552*	N/A	0.947*
Total ChulaPD ADL score	0.402*	0.199*	0.496*	0.364*	− 0.473*	0.351*	0.480*	0.493*	0.522*	0.502*	0.947*	N/A

Items

Age

Disease duration

H&Y

LED

MoCA

UPDRS1

UPDRS2

UPDRS3

UPDRS4

Total UPDRS

Sum score

of grading limitation

Total ChulaPD

ADL score

Sum score of grading limitation

0.479*

0.193*

0.558*

0.360*

− 0.523*

0.372*

0.544*

0.547*

0.550*

0.552*

N/A

0.947*

Total ChulaPD ADL score

0.402*

0.199*

0.496*

0.364*

− 0.473*

0.351*

0.480*

0.493*

0.522*

0.502*

0.947*

N/A

The statistical analysis was performed using Spearman’s correlation, p < 0.05 indicating statistical significance. MoCA Montreal Cognitive Assessment, ADL Activity of daily living, LED Levodopa equivalent dosage, UPDRS Unified Parkinson’s Disease Rating Scale.

Table 6. Represents Spearman’s correlation between The ChulaPD ADL score and the unified parkinson’s disease rating scale.

Items	UPDRS1	UPDRS2	UPDRS3	UPDRS4	MoCA
Sum of grading limitation	0.372*	0.544*	0.547*	0.550*	− 0.523*
1. Sum feeding	0.445*	0.452*	0.499*	0.478*	− 0.434*
2. Sum bladders/Toilet use	0.228*	0.417*	0.406*	0.442*	− 0.409*
3. Sum bowels/Toilet use	0.219*	0.280*	0.295*	0.325*	− 0.254*
4. Sum bathing/Shower	0.317*	0.394*	0.416*	0.462*	− 0.400*
5. Sum dressing/Grooming	0.240*	0.389*	0.411*	0.443*	− 0.392*
6. Sum dexterity	0.201*	0.334*	0.360*	0.339*	− 0.362*
7. Sum mobility/Transfer/Stairs	0.299*	0.387*	0.418*	0.431*	− 0.399*
8. Sum sleeping (Motor)	0.226*	0.303*	0.307*	0.354*	− 0.327*
9. Sum sleeping (Non-motor)	0.150*	0.209*	0.222*	0.252*	− 0.218*
10. Sum cognition	0.243*	0.369*	0.369*	0.398*	− 0.385*
11. Sum mood/Emotion	0.050	0.046	0.054	0.094	− 0.010*
12. Sum pain/Paresthesia/Discomfort	0.209*	0.258*	0.238*	0.294*	− 0.242*
13. Sum communication	0.166*	0.272*	0.265*	0.302*	− 0.267*
14. Sum sexual function	0.247*	0.236*	0.268*	0.299*	− 0.284*
15. Sum vision	0.211*	0.250*	0.262*	0.306*	− 0.263*
Total ChulaPD ADL scores	0.351*	0.480*	0.493*	0.522*	− 0.473*

Spearman’s correlation was conducted to identify the relationship between ChulaPD ADL questionnaire score and patients’ demographic, and Clinical rating scales, including H&Y, MoCA, and UPDRS score, revealed the following results as in the Table 5; Moderate correlation were found for sum score of grading limitation and age (r = 0.479, p < 0.05), total ChulaPD ADL score and age (r = 0.402, p < 0.05), sum score of grading limitation and H&Y (r = 0.558, p < 0.05), total ChulaPD ADL score and H&Y (r = 0.496, p < 0.05), sum score of grading limitation and MoCA (r = − 0.523, p < 0.05), total ChulaPD ADL score and MoCA (r = − 0.473, p < 0.05), sum score of grading limitation and UPDRS 2 (r = 0.544, p < 0.05), total ChulaPD ADL score and UPDRS 2 (r = 0.480, p < 0.05), sum score of grading limitation and UPDRS 3 (r = 0.547, p < 0.05), total ChulaPD ADL score and UPDRS 3 (r = 0.493, p < 0.05), sum score of grading limitation and UPDRS 4 (r = 0.550, p < 0.05), total ChulaPD ADL score and UPDRS 4 (r = 0.522, p < 0.05), sum score of grading limitation and total UPDRS (r = 0.552, p < 0.05), total ChulaPD ADL score and total UPDRS (r = 0.502, p < 0.05). Results indicated significant functional limitations in multiple daily activities, correlating moderately with age, H&Y, MoCA, and UPDRS score.

Moreover, the Table 6 represents correlation between each item of functional limitation score and clinical rating scales as following; moderate correlations were found for sum feeding and UPDRS 1 (r = 0.445, p < 0.05), sum feeding and UPDRS 2 (r = 0.452, p < 0.05), sum feeding and UPDRS 3 (r = 0.499, p < 0.05), sum feeding and UPDRS 4 (r = 0.478, p < 0.05), sum feeding and MoCA (r = − 0.434, p < 0.05), sum bladders and UPDRS 2 (r = 0.417, p < 0.05), sum bladders and UPDRS 3 (r = 0.406, p < 0.05), sum bladders and UPDRS 4 (r = 0.442, p < 0.05), sum bladders and MoCA (r = − 0.409, p < 0.05), sum bathing and UPDRS 3 (r = 0.416, p < 0.05), sum bathing and UPDRS 4 (r = 0.462, p < 0.05), sum bathing and MoCA (r = − 0.400, p < 0.05), sum dressing and UPDRS 3 (r = 0.411, p < 0.05), sum dressing and UPDRS 4 (r = 0.443, p < 0.05), sum mobility and UPDRS 3 (r = 0.418, p < 0.05), and sum mobility and UPDRS 4 (r = 0.431, p < 0.05). Results indicated significant functional limitations in multiple daily activities (including feeding, bladders, bathing, dressing, and mobility) correlating moderately with UPDRS scores.

Predictive factors and relative cut-off the sum score of grading limitation for determining postural instability

Binary logistic regression analysis was undertaken in which the prevalence of postural instability was a dependent variable, and participant-related variables were selected to run into the logistic model as independent variables. Postural instability was identified by patients’ reports and/or those with H&Y scores equal to or more than three scores. The logistic model was undertaken using the all enter method technique to select the most predictable variables to determine postural instability, and the predictors were reported as odds ratios. The model was conducted to identify possible predictive factors for postural instability, including age, disease duration, LED, grading limitation score, and the ChulaPD ADL score. Nagelkerke’s R² of 0.456 indicates a moderate relationship of 45.6% between the predictors and the prediction. The Hosmer and Lemeshow test showed a goodness of fit for the model, with a chi-square of 9.404 (p-value = 0.309). Prediction success overall was 81.8%. The forward (wald) method criterion demonstrated the EXP(B) value. It indicated that age more or equal to 60 years old, high dose of LED, and sum score of grading limitation was a significant predictive factor of postural instability with an odds ratio of 3.158 (95% CI for 1.423–7.004), 1.003 (95% CI for 1.002–1.004), and 1.217 (95% CI for 1.084–1.366), respectively (p < 0.05, each). Receiver operating characteristics (ROC) analysis was calculated for cutoff points for factors that might determine postural instability (Fig. 1). We also found that the sum scores of grading limitation could be cut off for patients with no postural instability. By using the cut-off score of more than and equal to 13 points, we could be able to identify those patients who have postural instability with a sensitivity of 81.4%, specificity of 50.7%, and AUC of 0.747 (p < 0.00; 95% CI for 0.677–0.817), suggesting that the sum score of grading limitation was able to distinguish between those patients who are with or without postural instability.

[See PDF for image]

Fig. 1

The ROC curve with a cut-off score of 13 points for the sum score of grading limitation identified patients with postural instability with a sensitivity of 81.4%, specificity of 50.7%, and an AUC of 0.747 (p < 0.001; 95% CI for 0.677 – 0.817), suggesting that the sum score of grading limitation was able to distinguish between those patients who are with or without postural instability. Abbreviation: ROC; Receiver Operating Characteristic, AUC; Area Under the Curve, CI; Confidence interval.

Effect of ADL questionnaire on Sexual function and Gender-specific differences – sexual dysfunction (Tables 3, 7, and Supplementary data 5)

Table 7. Comparisons of the sum score of grading limitation and ADL limitation between genders.

Items	Male N = 132	Female N = 99	p-value
Age (years)	68.46 ± 12.39	66.76 ± 10.70	0.274
Disease duration (years)	11.45 ± 6.21	12.14 ± 6.59	0.414
Hoehn and Yahr score	3.04 ± 1.22	2.94 ± 1.24	0.548
Levodopa equivalent dosage (mg)	990.63 ± 640.66	759.174 ± 420.35	0.002*
MoCA score	26.59 ± 3.55	26.53 ± 3.65	0.891
UPDRS part 1 score	2.14 ± 1.96	1.78 ± 1.74	0.151
UPDRS part 2 score	12.60 ± 6.86	11.82 ± 6.91	0.396
UPDRS part 3 score	27.48 ± 14.13	26.28 ± 14.91	0.535
UPDRS part 4 score	6.93 ± 5.54	6.04 ± 5.15	0.213
UPDRS total score	49.14 ± 27.40	45.92 ± 27.70	0.379
Sum grading of limitation	20.92 ± 10.67	18.61 ± 10.69	0.104
1. Sum feeding	1.25 ± 1.39	1.42 ± 1.47	0.360
2. Sum bladders/Toilet use	1.95 ± 1.53	1.73 ± 1.39	0.264
3. Sum bowels/Toilet use	2.52 ± 1.67	2.06 ± 1.73	0.046*
4. Sum bathing/Shower	1.04 ± 1.03	1.01 ± 1.02	0.839
5. Sum dressing/Grooming	1.39 ± 1.40	1.40 ± 1.49	0.927
6. Sum dexterity	2.14 ± 1.98	2.23 ± 2.09	0.744
7. Sum mobility/Transfer/Stairs	3.68 ± 2.36	3.62 ± 2.33	0.834
8. Sum sleeping (Motor)	3.83 ± 2.36	2.94 ± 2.37	0.008*
9. Sum sleeping (Non-motor)	4.58 ± 2.00	3.87 ± 1.97	0.007*
10. Sum cognition	2.94 ± 2.54	3.87 ± 1.97	0.105
11. Sum mood/Emotion	1.86 ± 1.51	1.61 ± 1.32	0.179
12. Sum pain/Paresthesia/Discomfort	1.86 ± 1.35	1.77 ± 1.35	0.593
13. Sum communication	3.42 ± 2.49	2.73 ± 2.454	0.041*
14. Sum sexual function	2.40 ± 2.63	1.09 ± 2.01	< 0.001*
15. Sum vision	2.66 ± 2.14	2.24 ± 2.25	0.153
Total ChulaPD ADL scores	58.44 ± 29.89	50.72 ± 30.10	0.054

The statistical analysis was performed using an unpaired t-test, p < 0.05 indicating statistical significance. MoCA Montreal Cognitive Assessment, ADL Activity of daily living, LED Levodopa equivalent dosage, UPDRS Unified Parkinson’s Disease Rating Scale.

For sexual evaluation, there was a statistically significant increase in grading limitations correlated with the Hoehn and Yahr (H&Y) score, showing a slight increase in the severity of grading limitations associated with more advanced H&Y stages (p < 0.001) as shown in the Table 3. Similarly, self-reported difficulties in impaired Sexual drive/ Arousal/ Loss of libido and impaired erection/moist also showed a slight increase in severity with more advanced H&Y stages (p < 0.001) (Table 3). However, there is no statistical significance in the other two sections on assistance requirements, environmental limitations, consequences, complications, and psychosocial interactions/health hazards with H&Y stages. During periods of motor fluctuations, sexual function also exhibited no discernible effect, regardless of the stage of the disease (p = 0.293) (Table 3).

In terms of gender-specific differences, the questionnaire findings indicated that males experienced more pronounced effects compared to females in several aspects (Fig. 2). The questionnaire findings indicated that males experienced more pronounced sexual dysfunction compared to females (Table 7). The severity of the limitations was worse in males than in females. Male participants exhibited greater impairment in various sexual aspects, including sexual drive, arousal, loss of libido, erection/moisture issues, reaching orgasm, and hypersexuality, compared to females. Moreover, in the section on consequence, complication, and psychosocial interaction/Health hazard, males showed more pronounced impairments in intimate relationships, mood, and satisfaction with sexual activities compared to females, indicating a gender-specific difference in these areas. During periods of motor fluctuations, gender-specific differences were observed, with males experiencing an impact on sexual function during such times while females did not. Moreover, male patient consumed higher LED compare to female patients (p = 0.002) (Table 7 and Supplementary data 5).

[See PDF for image]

Fig. 2

Male participants showed greater impairments in various aspects, including sexual drive, arousal, libido loss, erection/moisture issues, orgasm, and hypersexuality. Males also had more pronounced impairments in intimate relationships, mood, and satisfaction with sexual activities. During motor fluctuations, gender-specific differences were noted, with males experiencing an impact on sexual function, while females did not. Abbreviation: H&Y; Hoehn and Yahr score.

Evolution of ADL limitations, requirement of assistance, and consequence in different H&Y stages

The non-motor symptoms, including sleeping problems, bowel control, pain, mood/emotion, and communication difficulties, were rated as the top five ADL limitations rather than motor symptoms in patients with H&Y stage 1. From the patient’s perspective, the most disabling motor symptoms in the earliest stage were impaired mobility, followed by dexterity dysfunction (Fig. 3). However, these symptoms were not as pronounced as non-motor symptoms, such as sleep and bowel function issues. However, when H&Y stage 3 was reached, mobility became the highest limitation, followed by sleep problems and bowel dysfunction. The ADL limitation was flipped from non-motor to motor symptoms, particularly axial controls, when the disease progressed to H&Y stage 3. Mobility impairment remained the most significant limitation compared to other motor and non-motor symptoms in H&Y stages 4 and 5. As the disease progressed to H&Y stage 5, patients reported significant limitations in sleep, followed by communication and fine motor control activities. Bathing and dressing were reported as the lowest ADL limitations in the H&Y stage 1, but they became high-ranking limitations in the advanced stages from patients’ perspectives. Mobility required the most assistance and caused consequences in the earliest stage. It remained a key requirement for assistance but less than self-ADL tasks in the later stages of diseases. Dexterity was the second ADL with the need for assistance and environmental limitation in H&Y stage 1. However, it became less required than bathing and dressing as the disease progressed.

[See PDF for image]

Fig. 3

From the patients’ perspective, impaired mobility and dexterity dysfunction were the most disabling motor symptoms in the earliest stage, while non-motor symptoms like sleep and bowel issues were more pronounced. By H&Y stage 3, mobility became the highest limitation, with a shift from non-motor to motor symptoms. In stages 4 and 5, mobility remained the greatest limitation, with significant sleep and communication issues. Abbreviation: H&Y; Hoehn and Yahr score.

Discussion

Our research has underscored the validity and reliability of the ChulaPD ADL questionnaire in offering a comprehensive evaluation of ADLs across various dimensions. The study revealed a rise in daily activity constraints in tandem with the advancement of the H&Y stage and UPDRS score, signifying the mounting challenges encountered by individuals with PD as the condition evolves. Our findings identified substantial functional restrictions in diverse daily activities, demonstrating a moderate correlation with age, H&Y stage, and UPDRS score, underscoring the necessity for tailored interventions corresponding to each PD stage. Furthermore, item analysis revealed that each of the five ADL tasks—feeding, bladder control, bathing, dressing, and mobility—showed moderate positive correlations with UPDRS motor scores (UPDRS3), which reflect higher disease severity. This indicates a moderate contribution of these five ADL tasks to overall daily living independence. In contrast, items such as bowel control, dexterity, sleep, mood, cognition, pain, communication, sexual function, and vision demonstrated lower correlations, possibly reflecting greater variability in disease expression or the use of compensatory strategies among participants. Additionally, item analysis showed that three ADL tasks—feeding, bladder control, and bathing—had moderate negative correlations with MoCA scores, indicating an inverse relationship; greater functional limitations were associated with more pronounced cognitive impairment.

In the early phases of PD, patients could benefit from occupational therapy interventions to restore impaired skills and fortify compensatory mechanisms to uphold independence. Conversely, individuals in the later stages may necessitate more extensive support, including equipment assistance, to ensure safe, efficient, and confident engagement in their daily routines^22,23. This progressive pattern of activity limitation stresses the critical role of ongoing Occupational Therapy (OT) interventions in adeptly addressing the dynamic needs of PD patients, facilitating their journey toward regaining independence²². Ultimately, several potential interventions are guided by the ChulaPD ADL questionnaire results. For example, domains with the highest limitation scores—particularly those related to fine motor tasks and mobility—highlight areas where individuals with Parkinson’s disease may benefit most from targeted support. For instance, occupational therapy interventions focusing on hand function, dressing, and utensil use could be prioritized for patients exhibiting high impairment in those specific ADL domains. Similarly, environmental modifications such as installing grab bars, using adaptive utensils, or rearranging household layouts may help reduce task difficulty and promote independence. By aligning clinical interventions with domain-specific impairments identified through the ChulaPD ADL questionnaire, healthcare providers can more effectively tailor management plans to individual needs.

Moreover, A clear distinction was found between those with postural instability and those without. Patients with postural instability had significantly higher sum scores of grading limitation than their counterparts without (22.88 ± 9.86 vs. 13.80 ± 9.85, p < 0.001). This higher sum score reflects greater impairment in various functional domains. Specifically, these patients exhibited significantly higher scores in both motor and non-motor ADL sections throughout the day and night, including feeding, toilet use, bathing/showering, dressing/grooming, dexterity, mobility, cognition, communications, vision, pain, and sleep problems. These findings indicated that postural instability can impact all facets of daily functioning, aligning with prior research indicating similar outcomes^{24, 25–26}. The heightened scores observed in diverse ADL sections imply that postural instability intensifies challenges in executing daily activities and managing the varied symptoms linked with PD. This underscores the critical necessity for tailored interventions to alleviate postural instability and its associated complexities.

Upon an in-depth examination of the progressive limitations in ADLs across various H & Y stages and UPDRS scores, our investigation unveiled a nuanced shift in priorities in PD. In early PD stages, motor symptoms were not the primary focus, but their significance surged as the disease advanced. Instead, non-motor symptoms, notably disruptions in sleep patterns and bowel functions, emerged as pivotal concerns cutting across all stages, accentuating the imperative need for addressing these issues in clinical practice. The prominence of motor symptoms heightened as the disease progressed, particularly with the onset of movement restrictions at H&Y stage 3. Our current findings align with a previous study we conducted pinpointing the predominant worries of PD patients at different H&Y stages, revealing that individuals in the early stages (H&Y 1) were more troubled by non-motor symptoms than motor symptoms. This trend reversed for those in advanced PD stages²³. Noteworthy among motor symptoms is the unsettling prominence of mobility challenges, which manifest early in PD and evolve into critical ADL limitations, often necessitating aids like walking devices and home modifications, ultimately contributing to issues such as falls in advanced disease stages^4,27. These observations echo earlier research emphasizing gait and postural instability as vital indicators of disease progression^28,29.

Furthermore, these results underscore the crucial nature of initiating gait and balance rehabilitation early in the disease trajectory and maintaining these interventions throughout all stages of progression^28,29. As expected, dexterity challenges affecting instrumental ADLs—such as manipulating utensils, using electronic devices, or writing—exhibit mild impairment in early PD but progressively deteriorate as the disease advances, highlighting the need for specialized tools for fundamental ADLs, including user-friendly utensils, carefully designed pill dispensers, and assistive computer accessories^27,30.

The influence of activities during motor fluctuations did not markedly affect the majority of ADLs, implying that these daily functions might not fluctuate directly with medications but are more contingent on disease severity levels. However, gender-specific differences emerged concerning sexual function, with male patients exhibiting more pronounced sexual dysfunction compared to their female counterparts, consistent with prior research³¹. This gender distinction persists even during motor fluctuations, as observed in our study, signaling that addressing sexual impairments in male patients may require a multifaceted approach involving a combination of interventions to enhance sexual function alongside adjustments to anti-Parkinsonian medication to effectively mitigate motor fluctuations.

Our study unveiled substantial constraints in multiple daily activities strongly associated with PD severity, consistent with past research³². Timely identification of these ADL limitations may aid in the early detection or prevention of patients at risk of adverse disease outcomes and swift progression. Compared to the widely used UPDRS Part II, the ChulaPD ADL questionnaire offers a more granular and culturally tailored assessment of activities of daily living (ADL) among Thai patients with Parkinson’s disease. While UPDRS Part II provides a standardized global measure, it may not fully capture nuances in daily functioning that are culturally specific or particularly relevant in a Thai context. The ChulaPD questionnaire incorporates culturally relevant domains and daily tasks, enhancing sensitivity to patient-reported disability and enabling a more precise characterization of functional impairment. Addressing these obstacles could improve healthcare providers’ ability to support PD patients in safeguarding their independence and enhancing their overall quality of life³³. Effective management strategies could encompass targeted physical therapy emphasizing balance and strength training, customized medication plans, and comprehensive support for ADL engagement³⁴. The overarching aim is to craft holistic care strategies that effectively tackle PD’s motor and non-motor symptoms, with a specific emphasis on those amplified by postural instability³⁵.

An essential strength of the ChulaPD ADL Questionnaire is its design to reflect the patient’s daily, real-life functional status, accounting for both ON and OFF motor states commonly experienced in PD. The tool offers a more comprehensive understanding of ADL impairment by instructing patients to evaluate their abilities across a typical day and incorporating items sensitive to fluctuation-related challenges. This approach acknowledges the dynamic nature of PD symptoms and enhances the ecological validity of the functional assessment. The significant escalation in activity limitations observed with each advancing H&Y stage underscores the essential requirement for continuous evaluation and personalised intervention strategies to adeptly address the evolving challenges encountered by PD patients^7,36,37. A key strength of our study lies in the capacity to enlist a substantial number of PD patients spanning all disease stages, offering a representative sample for ADL limitations encompassing both motor and non-motor facets of PD. Furthermore, our questionnaire stands out by delving into the influence of daily activities during periods of motor complications and shedding light on the repercussions of ADL on assistive technologies. However, this study also contained limitations due to being conducted in a single-center, urban academic hospital, which may limit the generalizability of findings to rural populations or non-Thai cultural settings. In addition, although significant group differences were observed, we did not adjust for age despite the relatively large standard deviation (11.70 years), which may have influenced the results. Additionally, no corrections for multiple comparisons, such as False Discovery Rate (FDR) or Family-Wise Error Rate (FWER), were applied. As a result, the potential for Type I error cannot be ruled out. These factors should be considered when interpreting the findings, and future studies are encouraged to include age as a covariate and apply appropriate statistical corrections to strengthen the validity and significance of the results. Moreover, the questionnaire is newly developed and preliminarily tested in a pilot group. However, it has not yet been validated through a published study. We are currently conducting a comprehensive validation study using a larger, multi-center cohort to enhance its academic rigor. The results of this validation will be submitted for peer-reviewed publication as a standalone paper. In addition, in the present study, we examined the relationship between the ChulaPD ADL Questionnaire and established clinical rating scales commonly used in PD, including the UPDRS and the MoCA. While the ChulaPD ADL Questionnaire may provide a more detailed overview of patients’ functional capabilities, its specific advantages and incremental clinical value over existing standardized tools remain uncertain. Further research is warranted to determine whether the ChulaPD ADL Questionnaire captures distinct aspects of daily functioning that are not adequately reflected in these widely used measures. Although the ChulaPD ADL Questionnaire demonstrated a broad distribution of scores across all five stages (Table 3), we acknowledge the potential for minimal ceiling or floor effects. While our data did not show a concentration of responses at the extreme ends, ongoing validation in larger and more diverse populations is recommended to confirm the tool’s sensitivity across the full spectrum of disease severity. Finally, extrapolating postural instability from ADL scores alone warrants caution. The inclusion of the ROC analysis was exploratory and intended to demonstrate the potential clinical relevance of ADL scores, not to propose them as a standalone diagnostic tool for postural instability and that require further validation in future studies. Also, the study cohort included patients across a broad range of disease severities. Longitudinal validation of the questionnaire has not yet been completed. Therefore, forthcoming research endeavors should center on developing precision therapies to holistically improve the overall quality of life and functional outcomes for individuals grappling with PD³⁸. Breakthroughs in wearable technology and assistive devices hold promise in amplifying independence and safety during daily activities for PD individuals³⁹.

In conclusion

The ChulaPD ADL questionnaire is a relevant, reliable, and valid assessment tool used to evaluate the ability of patients with PD to perform everyday functional tasks. It captures critical aspects of a patient’s independence, such as feeding, bathing, dressing, and mobility. By providing intricate insights into the daily living challenges encountered by patients at different stages, this questionnaire facilitates clinicians and researchers in gaining deeper insights into PD progression, thereby aiding in the development of tailored, stage-specific management strategies to enrich patient quality of life. Utilizing this comprehensive tool to pinpoint ADL constraints can guide management approaches. Therefore, ongoing research endeavors are crucial to cater to the evolving needs of individuals with advanced PD and to improve therapeutic interventions.

Acknowledgements

This research was funded by the following grants; the Thailand Science Research and Innovation Fund (Program Management Unit for Competitiveness, C01F670185), the National Economic and Social Development Council, Thailand Center for Excellence for Life Sciences (TC (ERP) 31/2568), National Research Council of Thailand (N42A680591, N35E680087), the Centre of Excellence grants of Chulalongkorn University (CE68_028_3000_004), and the Thai Red Cross Education and Research Committee.

Author contributions

R.B., O.P., P.P., and J.S. designed the study and developed the ChulaPD ADL questionnaire. W.J., S.P., C.A., and K.S. conducted data collection. O.P. and W.J. conducted data analysis and interpretation. O.P. wrote the first draft of the manuscript. P.P. and J.S. reviewed and commented on the second draft of the manuscript. R.B. reviewed and finalised the manuscript. All authors read and approved the final manuscript.

Data availability

The raw data required to reproduce these findings cannot be shared at this time as the data is from an ongoing study. If necessary, some or all of the data used in the study is available from the corresponding author upon reasonable request.

Declarations

Competing interests

The authors declare no competing interests.

Ethical approval

Ethical approval for this study was obtained from the Faculty of Medicine’s ethical committee at Chulalongkorn University (IRB No.134/62 and COA No.0776/2024). Information regarding this research study was provided and written informed consent was obtained from every subject at enrollment, in accordance with the declaration of Helsinki.

Consent to participate

Information regarding this research study was provided and written informed consent was obtained from every subject at enrollment, in accordance with the declaration of Helsinki.

Abbreviations

ADLs

Activities of daily living

Parkinson’s disease

H&Y score

Hoehn and Yahr score

LED

Levodopa equivalent dose

AUC

Area under the curve

MoCA

Montreal cognitive assessment

UPDRS

Unified Parkinson’s disease rating scale

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1038/s41598-025-09444-7.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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The ChulaPD ADL questionnaire is a meticulously developed tool by experts in Parkinson’s disease (PD) and movement disorders, designed to assess functional limitations in daily activities. It comprehensively evaluates 15 key aspects of daily life through 115 items, including 15 for grading limitations and 100 for ADL limitations. Validated in a pilot study with 30 PD participants, the questionnaire demonstrated strong reliability. In a larger cohort of 231 PD patients, it showed moderate to high correlations with age, Hoehn and Yahr score, levodopa equivalent dose, Montreal Cognitive Assessment, and various UPDRS scores, highlighting its effectiveness in capturing disease-related changes. A grading limitation threshold of 13 points or above was particularly effective in identifying postural instability, achieving 81.4% sensitivity and 50.7% specificity, with an area under the curve (AUC) of 0.747. This underscores its utility in reflecting disease progression and its impact on daily functions. The ChulaPD ADL questionnaire is a relevant, reliable, and valid tool for assessing activities of daily living in patients with PD.

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Title

Unlocking the daily impact of parkinson’s challenges through a comprehensive assessment using the ChulaPD ADL questionnaire

Author

Phokaewvarangkul, Onanong¹; Panyakaew, Pattamon¹; Sringean, Jirada¹; Jankates, Worawit¹; Phumphid, Saisamorn¹; Anan, Chanawat¹; Sanyawut, Kanyawat¹; Bhidayasiri, Roongroj²

¹ Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Bangkok, Thailand (GRID:grid.419934.2) (ISNI:0000 0001 1018 2627)
² Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn Centre of Excellence for Parkinson’s Disease and Related Disorders, Department of Medicine, Faculty of Medicine, Bangkok, Thailand (GRID:grid.419934.2) (ISNI:0000 0001 1018 2627); The Academy of Science, The Royal Society of Thailand, Bangkok, Thailand (GRID:grid.419934.2) (ISNI:0000 0000 8865 0534)

Pages

26212

Publication year

2025

Publication date

2025

Publisher

Nature Publishing Group

e-ISSN

20452322

Source type

Scholarly Journal

Language of publication

English

DOI

https://doi.org/10.1038/s41598-025-09444-7

ProQuest document ID

3231558890

Unlocking the daily impact of parkinson’s challenges through a comprehensive assessment using the ChulaPD ADL questionnaire

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