Effect of strategies to improve interhospital transports of critically ill patients on safety and costs: protocol for a systematic review and meta-analysis

Abstract

Introduction

Transporting critically ill patients between medical facilities can be hazardous and costly. Whether by road, fixed-wing aircraft or helicopter, many professional associations have proposed strategies to efficiently and safely transport patients at high risk of instability. Although these strategies have been assessed in some studies, no comprehensive synthesis of their benefits has been conducted to date. The aim of this study is to assess the effect of strategies to improve the safety and costs of interhospital transports for critically ill patients.

Methods and analysis

We will conduct a systematic review according to the Cochrane guidelines. The review will include randomised controlled trials (RCTs), cohort studies and case-control studies assessing the effect of interventions to improve interhospital transports of critically ill patients on safety and costs. We will search multiple electronic databases (PubMed, EMBASE, CINAHL, Web of Science, Cochrane Library) from inception to 6 months prior to the submission of the final manuscript. Screening by title and abstract, full-text screening, data extraction and quality assessment will be performed by two independent reviewers. We will assess the risk of bias with the Cochrane revised tool for RCTs and with the risk of bias in non-randomised studies of interventions tool. If possible, we will calculate pooled effect estimates and 95% CIs to assess the effect of the interventions. We will also assess heterogeneity using the I² index and rate the certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation tool and trial sequential analysis.

Ethics and dissemination

Ethics approval is not required for this review. The results of this systematic review will be shared through publication in a peer-reviewed journal, conference presentations and our network of knowledge user collaborators.

PROSPERO registration number

International Prospective Register of Systematic Reviews (CRD42024595080).

Correspondence to Fabian Severino; [email protected]

STRENGHTS AND LIMITATIONS OF THIS STUDY

• We will conduct a comprehensive literature review to synthesise the effect of strategies aimed at improving interhospital transfers of critically ill patients.

• The search strategy will be developed by an information specialist and validated by a scientific librarian, both specialists in systematic reviews.

• We will use an exhaustive search strategy, identifying relevant citations in five databases, with no date or language restrictions.

• A limited number of studies or the heterogeneity of the interventions retrieved may prevent undertaking a meta-analysis.

Introduction

Interhospital transports have increased worldwide, becoming common practice in various healthcare systems.^1–3 It is estimated that over 500 000 critically ill patients are transferred between healthcare facilities each year in the USA⁴ and nearly 10 000 in the UK.⁵ The regionalisation of care and the growing number of specialised hospitals to meet patients’ advanced care needs, such as those with critical illness, are significant contributing factors to frequent patient transports.^{2 3} Critically ill patients are typically cared for in a variety of care settings, including the emergency departments, intensive care units, the step-down units and the coronary care units. They may be transferred using road ambulances, fixed-wing aircrafts and helicopters.¹ Numerous factors, such as the severity of the patient’s injury or illness, the distance to be covered, the training of healthcare professionals, the weather conditions and the associated costs, should be considered when determining the most suitable method of patient transfer.¹

Independent of the reason behind the transport, its ultimate purpose is to ensure that the patient arrives at the destination in the same condition as he or she left the original care setting. In a critical care context, Kiss et al² defines interhospital transport as the ‘transportation of a patient between medical facilities without interruption of the medical treatment and monitoring due to the underlying disease by means of specific medical, technical equipment and knowledge with the objective of improved care’. In other words, it is expected that the transport conditions will be safe, not harmful to the patient and carried out in an efficient manner, optimising processes and using the available resources in the best possible way.

The clinical condition of critically ill patients is inherently variable, increasing their susceptibility to adverse events during transfers.¹ A recent meta-analysis indicated that interhospital transfers may result in adverse events in up to 16% of critically ill patients.⁶ Subgroup analyses highlighted that respiratory failure patients from COVID-19, those undergoing extracorporeal membrane oxygenation (ECMO), and those having suffered a stroke were more likely to experience adverse events during transport. In this regard, adverse events are commonly grouped into categories such as patient-specific adverse events (eg, hypotension, bradycardia), technical incidents or equipment failures (eg, gas supply problems, missing equipment, power failure) and logistics incidents (eg, vehicule breakdown, inability to access the hospital on arrival).^{1 7}

Various recognised professional associations (eg, the American College of Critical Care Medicine,⁸ the Air and Surface Transport Nurses Association⁹), have endorsed structure and process strategies deemed crucial for the safe interhospital transfer of critically ill patients. These strategies have been assessed in some studies,^{3 10–15} but no comprehensive synthesis of their benefits has been carried out to date. Therefore, the aim of this systematic review is to assess the effect of strategies designed to improve the quality of interhospital transports of critically ill patients on their safety and associated costs. This review will enable us to identify strategies that should be incorporated into quality improvement initiatives for the interhospital transports of highly vulnerable patients, while using healthcare resources wisely.

Methods and analysis

We will conduct this systematic review according to Cochrane’s methodology¹⁶ and this protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) for Protocols statement (online supplemental file 1).¹⁷ This protocol was developed in collaboration with our advisory committee including critical care nurses, decision makers, emergency department physicians, intensivists and researchers. We submitted the protocol for registration in the International Prospective Register of Systematics Reviews (CRD42024595080).

Patient and public involvement

No patients are involved throughout the study.

Eligibility criteria

We defined our eligibility criteria using the Population, Intervention, Comparator, Outcomes and Study design approach.¹⁶

Participants

We will include studies on critically ill patients transported between two medical facilities, regardless of patient’s age and mode of transportation (eg, ambulances, fixed-wing aircrafts and helicopters). Critically ill patients are defined as those experiencing ‘a state of ill health with vital organ dysfunction, a high risk of imminent death if care is not provided and the potential for reversibility’.¹⁸ Critically ill patients typically originate from critical care units such as emergency departments, intensive care units, step down units, respiratory care units, burn units and coronary care units.^{18 19}

Interventions

We will include studies on any strategy designed to improve the quality of interhospital transports. The Donabedian model to evaluate the improvement in quality of care²⁰ will guide the classification of strategies. According to this model, the strategies should specifically target one of the following structure and/or process elements:

• Structure: use of specialised transport teams and vehicles; availability of training programmes for those involved in interhospital transports (as simulation and hands-on training for critical situations); protocols and/or procedures on patient transport, assessment and stabilisation; communication systems, use of telemedicine technologies; availability of advanced medical equipment and its maintenance.^{1–4 9 10 21–23}

• Process: well-defined coordination of care to initiate and coordinate interhospital transports; timely communication between referring and receiving healthcare teams; audit on adherence to protocols and procedures; implementation of checklists; communication between healthcare providers on patient’s medical history, current condition, treatment plan; use of standardised handover procedures; monitoring and response to any physiological changes or emergencies; administering medications or interventions; availability of healthcare providers trained to handle potential complications or deteriorations in the patient’s condition.^{1 4 9 24}

Comparator

Comparator will include interhospital transport based on usual care or any other strategies not aimed at improving the safety of interhospital transport.

Outcomes

We will consider studies that assess safety outcomes for interhospital transport of critically ill patients. According to the WHO,²⁵ patient safety is defined as the absence of preventable harm to a patient and a reduced risk of unnecessary harm associated with healthcare to an acceptable minimum. Patient-related harms,²⁵ including mortality and any complications defined by a recent consensus definition²⁶ such as respiratory failure (eg, de novo pulse oximeter readings (SpO2) ≤85%, respiratory arrest),^{6 26} extubation,^{18 26} vascular access problem,²⁶ cardiac arrest,^{6 26} life-threatening arrhythmia (eg, ventricular tachycardia or fibrillation),²⁷ hypotension (eg, defined as systolic blood pressure (SBP) <90 mm Hg for adults and children older than 10 years^{6 26 28}; SPB <70 mm Hg + (age in years x 2) for children aged 1–10 years^{26 28}; SPB <70 mm Hg for infants aged 1–12 months^{26 28}; SPB <60 mm Hg for neonates aged 0–28 days^{26 28}), neurologic deterioration (eg, ≥ 2 units on the Glasgow Coma Scale⁶), increased intracranial pressure (eg, ≥20 mm Hg) and intense pain (eg, ≥ 7/10²⁹) will be the primary outcomes. These events will have to occur during the transport or within an hour after, a delay deemed acceptable by the experts on our advisory committee to determine whether the patient’s deterioration can be explained by the quality of the transfer.

Secondary outcomes will include technical (eg, gas supply problems, equipment failure), system and organisational issues (eg, availability of transport, transfer delays, transport duration, missing equipment, inadequate use of equipment).^{1 7 21} Costs (eg, incremental cost-effectiveness ratio, incremental cost-utility ratio, incremental net monetary benefit, incremental net health benefit and the incremental cost-benefit ratio)³⁰ will also be considered as secondary outcomes.

Study design

We will include randomised controlled trials (RCTs), as well as prospective and retrospective cohort studies and case-control studies. We will exclude studies without a control group, as well as research protocols and abstracts.

Data sources

We will search the following databases: PubMed (National Institute of Health), Excerpta Medica database (EMBASE) (Ovid), Cumulative Index to Nursing and Allied Literature (CINAHL) (EBSCOHost), Web of Science (Clarivate) and Cochrane Library from inception to a maximum of 6 months prior to submission for publication. We will also search the grey literature through the Dissertations & Thesis Global (ProQuest). References of the identified studies will be manually screened for any studies not retrieved using our search strategy.

Search strategy

We will develop our search strategies in collaboration with an information specialist, which will be validated by a scientific librarian, using an iterative process according to the Peer Review of Electronic Search Strategies guidelines.³¹ We will use a combination of keywords and controlled vocabulary on the themes of patient transportation, interhospital and critically ill. We will apply the pilot strategy to the PubMed database. We will then add these words and indexing terms to the search strategy, which will be executed in PubMed and other targeted databases. There will be no date and language restriction. Articles in languages other than English and French will be translated with DeepL (http://www.deepl.com/translator).³² Using a preliminary search strategy in the MEDLINE (PubMed) database (table 1), we have identified 3298 citations, including 7 sentinel articles^{3 10–15} identified a priori, indicating good sensitivity and specificity.

Table 1

Preliminary search strategy in the MEDLINE (PubMed)

Concepts	Search strategy keywords	Research
Patient transportation	“Patient Transfer”[Mesh] OR “Transportation of Patients”[Mesh:NoExp] OR “ambulances”[MeSH]	#1
(Controlled vocabulary)	Transfer*[Title/Abstract] OR transport*[Title/Abstract] OR Ambulance*[Title/Abstract] OR helicopter* OR aeromedical	#2
(Free text)	1 OR 2	#3
Interhospital (No controlled vocabulary) (free text)	interhospital[Title/Abstract] OR “inter-hospital”[Title/Abstract] OR Interfacilit*[Title/Abstract] OR “Inter-facilit*”[Title/Abstract]	#4
Critically ill	“Critical Care”[Mesh:NoExp] OR “Critical Illness”[Mesh] OR “Emergency Service, Hospital”[Mesh] OR “Intensive Care Units”[Mesh:NoExp] OR “Burn Units”[Mesh] OR “Coronary Care Units”[Mesh] OR “Respiratory Care Units”[Mesh]	#5
(Controlled vocabulary)	trauma[Title/Abstract] OR “Critical care”[Title/Abstract] OR “critically ill”[Title/Abstract] OR “Critical Illness”[Title/Abstract] OR “Intensive Care”[Title/Abstract] OR “Coronary Care”[Title/Abstract] OR burn[Title/Abstract] OR burns[Title/Abstract] OR “Respiratory Care”[Title/Abstract] OR emergenc*	#6
(Free text)	5 OR 6	#7
Total	3 AND 4 AND 7	#8

Data management

We will import all studies retrieved from the different databases into Covidence³³ for screening. All duplicates will be deleted using electronic and manual screening.³⁴ A pair of reviewers (FS, SO) will independently screen titles, abstracts and full texts. To ensure the reliability of the selection process, both reviewers will use a systematic and iterative approach to pilot test the process on a random selection of 250 article citations until acceptable agreement is achieved (kappa >0.8).¹⁶ Any discrepancies during the review process will be resolved by consulting a senior member of the research team (MB).

Data collection process

We will create a standardised data extraction form that will be pilot tested iteratively by two reviewers (FS, SO) with methodological and content expertise, on a random selection of five studies until acceptable agreement is achieved (kappa >0.8).¹⁶ Reviewers will extract information on the following themes from original studies: setting (country, year, funding), population (age group, critical care condition, reason for transportation), study design, sample size, strategies (structures and/or processes), comparator, outcome measures and effect measures (eg, OR, relative risk, mean difference) and their 95% CIs. Any disagreement will be resolved through discussion between reviewers and, if necessary, consultation with a senior member of the research team (MB). If important information is missing or unclear, we will request it by sending up to three emails to the first, second and last authors. In case of failure, data will be considered missing.

Risk of bias

Two independent reviewers (FS, SO) will conduct the risk of bias assessment with the revised Cochrane Risk-of-Bias Tool (RoB 2) and the Risk of Bias in Non-Randomised Studies – of Interventions tool (ROBINS-I).^{35 36} We will use the RoB 2 to assess the risk of bias in RCTs. This tool considers five bias domains: randomisation process, deviations from the intended interventions, missing outcome data, measurement of the outcome and selection of the reported result. We will use the ROBINS-I tool to assess the risk of bias in observational studies. This tool includes seven bias domains: confounding, participant selection, classifications of interventions, deviations from intended interventions, missing data, measurement of outcomes and selection of the reported result. Each domain of bias and the overall bias will be assessed as low, moderate, serious, critical or no information. Both tools will be pilot tested on a random sample representing 5% of the included studies for consistency between reviewers. Any disagreements between the two reviewers will be first discussed between reviewers and resolved by a third senior reviewer (MB) if disagreement persists.

Data synthesis

A PRISMA flowchart will illustrate the study selection process.³⁷ The extracted data will first be presented as a narrative synthesis describing the main characteristics of the studies included. For each outcome, we will synthesise risk of bias assessments graphically according to each domain and the overall risk of bias.

If appropriate data are available in at least three of the included studies, we will conduct meta-analyses for primary and secondary outcomes using Reviewer Manager, V.7.2.0.³⁸ Intention-to-treat analyses will be conducted, and missing data will be managed using simple imputation.³⁹ To do this, we will use a worst-case scenario analysis, considering missing outcome data in the intervention group and those in the control group as beneficial, and an extreme worst-case analysis in which missing data are counted as non-beneficial in the intervention group and beneficial in the control group. Pooled effect estimates and 95% CIs will be computed using random effect models. We will assess studies’ heterogeneity with I² for each outcome. An I ²>50% will indicate high heterogeneity, 25% to 50% will indicate moderate heterogeneity, and <25% will indicate low heterogeneity.⁴⁰ We will use funnel plot asymmetry to assess publication bias and selective reporting of results.⁴¹

Subgroup and sensitivity analyses

To explore the causes of heterogeneity, provided there are a sufficient number of studies, we will conduct subgroup analyses according to last year of data collection, geographical location (eg, North America, Europe, Asia, Australia), strategy type (structures and processes), age groups (eg, neonate, children, adult), critical care conditions (eg,acute coronary syndrome, sepsis, surgery, trauma), healthcare providers (eg, physician, nurse, paramedics, respiratory therapist, mixed), transport mode (eg, air, ground, mixed) and risk of bias (low, medium, and high). Given that the level of implementation of structures and processes can affect outcomes, we will test the robustness of effects with studies that documented ≥75% adherence to strategies. We will also conduct worst-case and extreme-case scenario analyses to account for missing data.

Quality of the evidence

For each outcome measure, we will assess the level of evidence using the Grading of Recommendations Assessment, Development and Evaluation working group methodology.⁴² We will perform trial sequential analyses on the primary outcomes to monitor for boundary with heterogeneity-adjusted information size.⁴³ Trial sequential analyses will be conducted using 5% alpha and 80% power with a two-tailed test. We will grade the evidence from very low (the true effect is probably markedly different from the estimated effect) to high (the authors are very confident that the true effect is similar to the estimated effect). Grading will be performed independently by two reviewers (FS, SO), and conflicts will be resolved by a third senior reviewer if needed (MB).

Discussion

Critical interhospital transports are increasingly common and are often associated with many adverse events.^1–3 Our review will be conducted according to the highest standards,¹⁶ and we will search multiple databases, which could allow us to confidently identify strategies that reduce adverse events at the lowest costs. In addition, our rigorous approach could highlight gaps in the existing literature regarding interhospital transports strategies that require further research. Participation in this review of methodological experts as well as healthcare professionals from multiple disciplines and decision makers will also increase the likelihood of recommending strategies with the greatest potential to improve the quality of interhospital transfers and their cost-effectiveness, while facilitating knowledge uptake.

However, this review has some limitations. Despite our aim to conduct a review that discusses a variety of strategies, we anticipate that we will not be able to conduct meta-analyses of all the structure and process-related strategies identified. Likewise, we expect heterogeneity in terms of design, population, strategies and outcomes across studies, making it challenging to draw definitive conclusions. Finally, the generalisability of our findings could be limited to specific patient populations, healthcare settings or geographical regions, which could restrict the applicability of our findings.

Ethics and dissemination

Ethics committee approval is not required. No primary data will be collected. The results of this systematic review will be shared through publication in a peer-reviewed journal and presentations at conference meetings.

Ethics statements

Patient consent for publication

Not applicable.

Footnote

X @BrubMlanie1

Contributors FS, MB and MCG conceptualised and designed the review made substantial contributions to the manuscript. FS is the guarantor for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. FS and SO will be involved in data management, data collection and the evaluation of risk and bias. FS, MB, MCG, SO, EM, AL, AB, JSTR and CM were implicated in drafting the manuscript or revising it critically for improvement. They have all given final approval for publication of the manuscript and each author participated sufficiently in the work to take public responsibility for appropriate portions of the content.

Funding FS received funding from the Canada Graduate Scholarship - Master’s Award of the Canadian Institutes of Health Research and from the Leadership and Commitment Scholarship of Université Laval. FS is also supported by a clinical research grant from Foundation du CHU de Québec-Université Laval. Funders had no role in the design of the study or the decision to submit the paper for publication.

Competing interests FS, MCG, EM, CM, AB and MB are affiliated with organisation that funded the systematic review (Université Laval and/or CHU de Québec-Université Laval). Funders did not influence the content of this protocol and will have no influence on the results of the systematic review. All other authors have no competing interest to declare.

Patient and public involvement Patients and/or the public were not involved in the design, conduct, 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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