Effectiveness of concussion treatments in older adults: a systematic review protocol

Abstract

Introduction

Concussions can have significant implications on the health and quality of life of older adults. As most concussion research previously focused on children, athletes and military populations, there is a need to better understand the concussion-specific treatments for adults aged 65 and older. The aim of our systematic review is to review the existing literature on the effectiveness of concussion treatments on outcomes in adults aged 65 and older.

Methods and analysis

This systematic review will be conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines and the Cochrane’s Handbook for Systematic Reviews of Interventions. A comprehensive search of electronic databases (MEDLINE, Embase, CINAHL, AgeLine, APA PsycNet and Cochrane CENTRAL) will be performed and reference lists of included articles will be searched. We will conduct a two-step screening process and data extraction. The data analysis will integrate a narrative approach with vote-counting. The risk of bias in the included studies will be assessed, and the quality of evidence for each outcome will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Ethics and dissemination

The results of this systematic review will contribute to the current knowledge on concussion treatments and outcomes in older adults. This work is essential for identifying effective interventions and guiding future guidelines for this under-represented population. No ethical approval is needed for the review, and we plan to present the results at an international research conference and in a peer-reviewed journal. This protocol is registered in PROSPERO (CRD # pending).

Correspondence to Chantal Backman; [email protected]

STRENGTHS AND LIMITATIONS OF THIS STUDY

• Six databases will be searched, and we will include studies with concussion-related interventions and their outcomes for adults aged 65 and older.

• This protocol is registered in PROSPERO prior to the start of screening and data extraction.

• Findings may not be generalisable to populations under the age of 65.

• The review is limited to studies published in the English or French language.

Introduction

Concussions, also known as mild traumatic brain injuries (mTBI), can significantly impact health and quality of life in adults aged 65 and older.¹ Concussions are defined as injuries to the brain caused by external physical forces, with evidence of acute physiological disruption of brain function.² By definition, concussions do not present intracranial abnormalities on routine neuroimaging (eg, CT or MRI, if performed) and are not associated with loss of consciousness lasting more than 30 min or post-traumatic amnesia exceeding 24 hours.² While most individuals recover within a few months, up to 30% experience persistent symptoms beyond 3 months.^3–5 Diagnosing concussions in older adults is particularly challenging, as many acute and lingering symptoms overlap with those of pre-existing comorbidities, which are more prevalent in this population.⁵

An estimated 69 million people worldwide experience a concussion each year.⁶ Older adults with a history of depression and postconcussion symptoms may be at greater risk for prolonged symptoms and poorer outcomes following a concussion.⁷ Emergency visits for concussion-related injuries in older adults have risen significantly, paralleling population ageing and the public health burden of these injuries is expected to grow over the next two decades.⁸ However, most concussion research has focused on youth, sports-related injuries⁹ and military populations,¹⁰ leaving a significant gap in understanding concussion injuries in older adults.

In older adults, concussions are often caused by falls. Compared with younger individuals, older adults tend to experience more severe concussions, have longer hospital stays, are more likely to be discharged to long-term care and face a higher risk of in-hospital mortality.¹¹ Key risk factors for mortality include injury severity, low systolic blood pressure and being 74 years of age or older.¹² Additionally, frailty, characterised by reduced physiological reserve and impaired ability to maintain homeostasis, independently increases the risk of postconcussion complications.¹³ The ageing brain may also have a diminished capacity for recovery due to a lower neurological ‘reserve’.⁸

Traditional clinical management of concussion injuries was limited to cautious waiting.¹⁴ However, increased evidence has demonstrated that some patients who sustain a concussion benefit from earlier and more proactive interventions to prevent persisting symptoms after concussion.¹⁴ Expert groups have developed clinical practice guidelines including the Living Guideline for Concussion,¹⁵ Living Guideline for Paediatric Concussion¹⁶ and the Mild Traumatic Brain Injury Management Guideline¹⁷ for healthcare professionals to identify and treat individuals with concussions and persisting symptoms after concussion. However, no guidelines exist specifically targeting older adults. Although older adults account for less than 10% of all concussion cases, mortality at 6 months in this population reaches 50% for moderate to severe cases and 10% for mild cases.¹⁸ Therefore, it is important to identify interventions specific to this age group. Therapies with evidence of benefit in reducing the risk of persisting symptoms after concussion include early psychoeducation focused on return to function, graded return to physical activity,^{15 16 19} psychological treatment for mental health symptoms, vestibular or oculomotor rehabilitation²⁰ and symptom-targeted pharmacotherapy.²¹

The wide array of symptoms that may persist after a concussion includes cognitive, psychological, physical, emotional, sleep and somatic changes, which are also common in the non-injured general population and common with many comorbidities in older patients.

Previous research has mainly focused on the risk factors and prognosis of concussion injuries in older adults, particularly in relation to falls.²² Age-related declines in various physiological systems including musculoskeletal, cardiovascular, visual, vestibular, proprioception, coordination and cognitive function can heighten the risk of falls.²² Key risk factors include impaired balance and gait, polypharmacy and history of previous falls.²² Additional studies have explored the prognosis of concussion injuries,^{23 24} neuropsychological outcomes^23–27 and psychological interventions for persisting postconcussion symptoms.^{20 28}

To date, there are several reviews on the management of concussions. ^{20 29–31}One recent review (n=18 studies) explored concussion management in older adults and identified studies describing early management with little evidence on the general concussion management.²⁹ Another review (n=14 studies) found positive outcomes for postconcussion cognition, psychological health and life participation in older adults.³¹ Two other reviews summarised the interventions and outcomes for persistent postconcussion symptoms in all adults^{20 30} (n=55 studies, and n=10 studies, respectively). To the best of our knowledge, this is the first review to specifically look at the effectiveness of concussion treatment interventions in the older adult population. The aim of our systematic review is to review the existing literature on the effectiveness of concussion treatments on outcomes in adults aged 65 and older. The overall research question is: what is the effectiveness of interventions for treating concussions in improving outcomes for older adults?

Methods and analysis

Study design

This systematic review protocol was developed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines³² and the Cochrane’s Handbook for Systematic Reviews of Interventions.³³ This protocol is registered on PROSPERO (CRD # pending).

Eligibility criteria

The eligibility criteria are defined by the Population-Intervention-Control-Outcome-Type of studies (PICOT) format as follows:

Population

Older adults (aged 65 and older) with a concussion (brain/cerebral) or mTBI (terms used interchangeably in the literature).³⁴ In this review, we will consider both terms when searching the databases and extracting the data.

Interventions

We will include interventions designed to reduce symptoms and improve recovery at any time point following a concussion (ie, medications, early psychoeducation, telephone counselling, graded return to physical activity, psychological treatment, cognitive rehabilitation, vestibular or oculomotor rehabilitation²⁰). We will exclude studies that focus on assessing or diagnosing concussions, including those comparing imaging tests.

Controls

We will include studies that have a control group defined as usual care or any other intervention.

Outcomes

We will include studies that evaluate the effectiveness of the intervention(s), including outcomes related to physical symptoms (ie, headaches, vision changes, sensitivity to light or sound, balance problems and reduced exercise tolerance), cognitive symptoms, emotional symptoms (ie, easily upset, easily angered, feeling sad and nervous/anxious), sleep and fatigue, and mortality.

Types of studies

We will include randomised controlled trials, non-randomised experimental studies, cohort studies and cross-sectional studies. However, we will exclude case studies, literature reviews, conference papers, editorials, and commentary articles.

Search strategy

We developed a preliminary peer-reviewed search strategy up to July 2024³⁵ in consultation with a specialist health sciences librarian (LS), in MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), AgeLine (EBSCOHost), APA PsycNet and Cochrane CENTRAL (Ovid). No limits to language or publication date were applied. Although we are not applying any language filters, we will limit our review to studies published in English or French. The main search concepts are comprised of terms related to concussions and older adults. The search strategies are described in online supplemental appendix 1.

Screening

The search results will be exported to EndNote V.21 (Clarivate, Philadelphia, PA, USA) to remove duplicates and subsequently transferred to Covidence systematic review software (Veritas Health Innovation, Melbourne, VIC, Australia) for storage and screening. The screening process will be carried out independently by four reviewers (FDE, ATF, RP and AL) who will work in pairs to screen the articles following a two-step process: titles/abstracts and full text. Any disagreements between the reviewers will be resolved by discussion with a fifth reviewer (CB). To ensure accuracy and consistency, consensus between reviewers will be monitored periodically. For the full-text screening phase, all full texts will be added to Covidence. In addition, the references of including articles and existing reviews on the subject will be screened against our eligibility criteria for possible inclusion in our study. Articles not available in open access will be requested from the university library. Any articles that are not found with the assistance of the library after the screening phase is completed will be excluded.

Data extraction

The data extraction of eligible studies will be carried out independently by two reviewers (ATF and AL). A spreadsheet will be developed and piloted to include information on author name, year of publication, study location, purpose, theoretical framework (if any), study design, study population, a description of the intervention, setting and study outcomes.

Risk of bias and certainty of the evidence

Two reviewers will independently assess the risk of bias for each included study. For randomised trials, we will use the Cochrane Risk of Bias tool (RoB V.2),³⁶ and for non-randomised studies comparing two or more interventions, we will use the Risk of Bias in Non-Randomised Studies of Interventions (ROBINS-I V.2).³⁷ This will help identify potential sources of bias within the studies, including selection, performance, detection and reporting biases. Each domain will be rated as low, high or unclear risk of bias. Any disagreements will be resolved through discussion or, if necessary, by a third reviewer. No studies will be excluded based on quality alone; however, we will highlight any methodological weaknesses if they significantly impact data synthesis.

The certainty of the evidence for each outcome will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, and it will be based on five factors: study limitations, indirectness of evidence, inconsistency of results, imprecision and publication bias. We will assess the overall rating per outcome, based on our confidence that the estimates of the effect are correct, by rating them as high, moderate, low or very low.³⁸

Data synthesis

The included studies will be described narratively and grouped by intervention types (eg, rehabilitation, pharmacological treatment and guideline implementation). All outcomes will be reported according to the intervention type. In addition, we will provide a detailed summary of the characteristics and components of the interventions, such as duration, frequency, intensity and type of professionals involved in their execution. We will group the outcomes by type of symptom under the following categories: cognitive, physical, psychological and other. We anticipate substantial variation in the outcomes reported across included studies, which may limit the feasibility of conducting a meta-analysis. We will therefore apply a vote-counting approach,³⁹ in which we tally the number of studies reporting a statistically significant effect versus those reporting a non-significant effect for each outcome of interest. A significant relationship between the concussion treatment and the outcome of interest will be determined by the presence of a minimum of three studies with the same effect (eg, significant vs non-significant).⁴⁰ We will also report the magnitude of the effect for all the statistically significant results.

Ethics and dissemination

We will synthesise the available literature on the effectiveness of concussion-related interventions in older adults, including both pharmacological and non-pharmacological approaches to reduce symptoms, improve recovery and enhance function. This work is essential for identifying key interventions and shaping future guidelines for this under-represented population. The findings will highlight effective interventions for older adults and their impact on patient outcomes. Additionally, this review will identify areas where further research is needed, encouraging new studies to strengthen the evidence base in this field. No ethical approval is needed for the systematic review, and we plan to present the results of this research at a conference and in a peer-reviewed journal.

Ethics statements

Patient consent for publication

Not applicable.

Footnote

Contributors FDE contributed to the initial draft of the systematic review protocol. All authors (FDE, SGF, ATF, RP, AL, LS, SJ, RZ, WL, SF, PT and CB) made substantial contributions to the protocol design. LS was responsible for developing the search strategy. All authors (FDE, SGF, ATF, RP, AL, LS, SJ, RZ, WL, SF, PT and CB) contributed to the critical review of the manuscript and approved its final version. CB is the guarantor of the review.

Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

Competing interests None declared.

Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting or dissemination plans of this research.

Provenance and peer review Not commissioned; externally peer reviewed.

Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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