Introduction

Falls among older adults account for 15% of emergency room visits and over 495 000 deaths worldwide, imposing significant burdens on patients, healthcare systems and society.1–4 Adults aged 65 and older report the highest incidence rate of falls; one-third of adults living in the community and one-half of adults in aged care will fall annually.1 3 5 6 Of these individuals, approximately one-quarter will sustain moderate to severe injuries with high morbidity and mortality rates, such as traumatic brain injury, hip fracture or lower extremity fracture.3 5 7–10 The age-adjusted fall-related death rate increased by 41% in the most recent decade (ie, 55.3/100 000 in 2012 to 78.0/100 000 in 2021), building on its steady rise since 2001.11 Additional common fall-related impacts include increased sedentary behaviour and fear of falling, both further increase fall risk.3 5 10 12 These factors create a vicious cycle, where each fall increases the risk of future falls. One-sixth of community-dwelling adults and two-fifths of individuals in aged care experience recurrent falls.1 3 10 13 14

The economic impacts of falls in older adults are substantial, with fall-related expenses accounting for 0.85%–1.5% of annual healthcare spending in high-income countries.13 15 A systematic review estimated the average cost per fall at US$15 212 (2022 prices), with falls requiring hospitalisation costing up to US$34 565 (2022 prices), depending on the severity of the injury and the length of stay.16 Falls in older adults are also associated with increased risk for significant functional and cognitive decline, with one-fifth of adults over 70 demonstrating a decreased ability to perform activities of daily living.3 12 Psychological impacts are also common, decreasing individuals’ confidence in their abilities and willingness to mobilise.12 Together, these factors are associated with greater healthcare utilisation, creating a significant burden for patients, their caretakers, the healthcare system and society.17–19 With the global population of older adults projected to reach 1.4 billion by 2030, developing efficient (ie, cost-effective) fall prevention strategies should be a global priority.13 20

Fall prevention interventions can be broadly split into three categories: physical activity or exercise, medical or physiological, and environmental. Physical activity refers to any bodily movement which increases energy expenditure above the resting or basal levels.21 A physical activity intervention focuses on increasing physical activity behaviour—either through behavioural change strategies (eg, coaching, messaging, resources, etc) or by prescribing physical activity in the form of exercise training. Exercise is physical activity for the purposes of increasing or maintaining physical fitness.21 An exercise intervention prescribes exercise training using a specific dose of exercise (ie, frequency, intensity, type, and duration), which is either maintained throughout the course of an intervention, or ideally, can be progressed over time by increasing the volume (ie, frequency × duration) or intensity of exercise performed.22

Exercise-based programmes structured with the goal of improving health or physical fitness are considered widely effective and are recommended as part of standard practice.3 5 10 13 23 A systematic review noted that exercise interventions demonstrated the most consistent benefits across multiple fall-related outcomes.11 Medical and physiological assessments, such as cardiovascular assessments, medication reviews and vision assessments, are also frequently recommended.3 10 13 24 Designed to address physiological risk factors related to falling, these intervention approaches are tailored to the patient’s individual risk profile.3 10 13 Environmental modifications, often referred to as home-safety improvements, include hazard removal and the installation of support structures to improve safety in the individual’s living space.3 10 13 25 Interventions in each category can be used alone as single-factor programmes, or combined to create general or patient-specific treatment plans, known as multicomponent or multifactorial programmes, respectively.3 10 While the implementation of intervention categories and modalities vary between nations, the interventions described above are well established, and are recommended in the WHO Step Safely guidelines and the World Falls Guidelines.3 13

Despite the strong evidence demonstrating the effectiveness of numerous fall prevention interventions, the rate of falls and fall-related outcomes is climbing.26 27 This can be partially attributed to the difficulties of translating research into clinical practice.26 28 Previous implementation studies have identified multiple barriers that prevent effective facilitation, many of which are not fully addressed in current research.28 Availability of resources is highlighted in multiple studies as a key limitation to effective implementation. Relevant to resource availability, existing guidelines for fall prevention have limited discussion on the cost of interventions.3 13 28 The lack of consistent, systematic methodology surrounding the creation of best practices also needs to be addressed.29 Many existing reviews are limited by intervention type, population subset or geographic origin, reducing the generalisability of their results.23–25 30–32 While both guidelines are broader in scope, their difference in criteria, level of stakeholder involvement and target audience resulted in recommendations that varied in strength and coverage.3 13 To better support patients, clinicians and health policymakers, a pragmatic guideline focusing on knowledge translation and the constraints of the healthcare system is required.

Living systematic reviews (LSRs) are defined as ‘a [type of] systematic review that is continually updated, incorporating relevant new evidence as it becomes available’.33 Reflecting this definition, LSRs maintain a continuous workflow, prevent the loss of institutional memory, conserve resources and ensure consistency over time.33 34 Transparent communication of an a priori commitment ensures that users understand the timing and content of each update.33–35 These characteristics provide comprehensive, relevant information on a predictable basis, thus making it valuable for the development of health policy and clinical guidelines.33 34 36 Hence, given the information we have on the effectiveness of fall prevention strategies,37 a LSR that details cost-effective fall prevention strategies is the next essential step in the research cycle38 towards informing evidence-based health policy decisions.

The aim of this LSR is to provide a comprehensive summary of the cost-effectiveness of existing and future fall prevention interventions for older adults aged 60 years and older in three settings: community-dwelling individuals, individuals in aged care facilities, and individuals residing hospital settings (ie, acute, rehab). Formation of a narrative synthesis and plain text summary will be guided by the following questions.

Which fall prevention interventions for older adults are cost-effective in three settings: community-dwelling individuals, individuals in aged care facilities, and individuals residing hospital settings?

Which factors (eg, geographic regions, demographics) impact the cost-effectiveness of fall prevention interventions for older adults?

Methods and analysis

This LSR protocol was developed in alignment with the reporting standards provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Protocols (PRISMA-P).39 The formal review will align with the reporting standards detailed by PRISMA.40 This review is registered with the Prospective Register of Systematic Reviews (PROSPERO). A copy of the completed PRISMA-P checklist can be found in online supplemental file 1.

Eligibility

Table 1 provides a summary of the eligibility criteria. Inclusion will be limited to peer-reviewed full economic evaluations on randomised controlled trials, controlled trials or economic models. Evaluations based on observational data, reviews, conference abstracts, protocol papers and grey literature will not be considered. Studies with more than half of participants 60 and over will be considered for inclusion.13

Table 1

Eligibility criteria for study inclusion

This review will include adults in three living settings: community-dwelling, aged care facilities and hospitals. However, to account for the differences in population risk factors and available resources, results will be stratified based on these three living settings.3 41–44 In studies where samples were drawn from multiple settings, separation of data will be required for study inclusion. Populations composed entirely of participants with condition-specific elevated fall risk (eg, Parkinson’s disease, cancer, multiple sclerosis, stroke, mild cognitive impairment, Alzheimer’s and other forms of dementia) will be excluded.3 10 13 44

Only interventions primarily designed and implemented to prevent falls will be included. There will be no restrictions placed on intervention duration, format and time horizon. Interventions will be broadly categorised as follows: exercise or physical activity programmes, medical or physiological assessments and environmental modifications. 21 Briefly, physical activity interventions generally focus on increasing or maintaining overall physical activity through behavioural change strategies whereas exercise interventions prescribe a specific dose of physical activity for the purpose of increasing or maintaining physical fitness.21 Exercise interventions can be progressed over time by increasing the volume (ie, frequency × duration) or intensity of the exercise performed.22

All standard comparator types for the control groups such as usual care, waitlist control and placebos will be included. Studies comparing two or more fall prevention interventions without the use of a no-effect comparator will be considered.

Both economic and health outcomes will be required for study inclusion. Primary economic outcomes will include incremental cost-effectiveness ratios (ICERs) for a falls-related outcome (ie, incremental cost per fall prevented, incremental cost per faller), incremental cost-utility ratios (ICURs) (ie, incremental cost per quality-adjusted life year (QALY) gained) and cost-benefit analyses (CBA). Values should be reported with respect to health-related quality of life (HRQoL) measures or QALYs. Briefly, incremental cost-effectiveness and cost-utility ratios are generally the primary result of economic evaluations; they are summary measures that assess the economic value of an intervention in comparison with an alternative (comparator).45 By definition, an ICER or ICUR is the difference between the costs of providing competing interventions divided by the difference in effectiveness/utility (that is, the number of falls prevented or QALYs gained).46 In cost-utility analyses, health benefits are measured by a QALY, and for CBA, in monetary units such as Net Monetary Benefit or Net Present Value. Net Monetary Benefit depends on an established willingness to pay a threshold for a unit of benefit and represents the value of an intervention in monetary terms.45 Net Present Values assess the difference between the present value of cash inflows and outflows.

Evidence of assessment of primary health and effectiveness outcomes will be required for inclusion. This may include one or more of the mean rate of falls, the number of falls prevented, the fall incidence rate ratio or the fall risk ratio to be considered for inclusion. If a study does not report an incremental measure of effectiveness, the economic evaluation will be included, provided the primary clinical paper demonstrated efficacy or effectiveness.

We will not place any restrictions on language and will rely on the language diversity among our team members to assist with translation. In instances where our team members are unable to translate languages, we may need to exclude the studies which we are not able to resource translation services for.

Information sources

The review will primarily incorporate publications from CENTRAL (Ovid), CINAHL (EBSCO), Embase (Ovid), MEDLINE (Ovid), SCOPUS (Elsevier) and Web of Science (Clarivate). Each database will be searched from inception to ensure the inclusion of studies that informed previous reviews and guidelines.

Handsearching will be used to complement retrieved materials following the primary search, including journals and studies indexed by EconLit and the Tufts CEA registry.

Search strategy

The search strategy was created in MEDLINE (Ovid) with guidance from two subject librarians. A combination of database headings and associated keywords were used to increase relevant results, with portions of the search trialled against Ovid Expert and Canadian Agency for Drugs and Technologies in Health search hedges.47 48 Following initial revision, the search strategy was piloted against target articles, which were identified as highly relevant due to inclusion in multiple prior reviews.10 23 24 29–32 49 The search strategy was translated for use in CENTRAL (Ovid), Embase (Ovid), CINAHL (EBSCO), SCOPUS (Elsevier) and Web of Science (Clarivate) following additional minor revisions. Systematic searches for EconLit and the Tufts CEA Registry were considered; on performing an overlap analysis for both resources, handsearching was determined to be sufficient.

A primary search will cover all included databases from inception to 4 March 2024, with the cut-off date being reported in the published manuscript. Following the cut-off date, databases will undergo monthly searches for relevant publications. These searches will be facilitated by platform-specific automated search alerts.

EconLit and the Tufts CEA Registry will be searched using keywords to identify articles relevant for inclusion. Reviews identified during the screening will undergo snowballing with the initial process covering one generation of references and citing material. This process will be facilitated through citationchaser.50 We will also search reviews and articles known to the author team. Following the base report, relevant reviews will have all citing material searched annually. Journals and authors repeatedly identified across multiple searches with relevant publications will have additional automated alerts created to identify new publications. Handsearching will occur for relevant resources on an annual basis.

Search strategies for each database are available in the online supplemental file 2.

Data management

Articles retrieved from searches will be archived in a reference manager before being uploaded into Covidence for deduplication and record management. Results of monthly searches will be uploaded separately to ensure clear delineation between versions.

Selection process

Screening will occur in two stages, with title and abstract screening followed by full text review. Title and abstract screening will be performed by a small team of reviewers. Each article will be independently screened by two reviewers. Prior to screening, eligibility criteria will be piloted on 1% of the articles retrieved from the initial search to ensure criteria are being consistently applied by all reviewers. Full text screening will share a similar distribution of responsibility between reviewers. Formal eligibility criteria will be piloted on 1% of relevant articles. Categories for article exclusion will be developed and reported via the PRISMA diagram. Any disputes in the screening process will be resolved by a third reviewer. Inter-rater reliability (IRR) will be calculated for both stages of screening.

Data collection process

Data extractions will be conducted for each study selected for full text review. A pilot of the data extraction process will be performed on 5% of all included articles. Any disputes in the extraction process will be resolved by a third reviewer. All data extraction will be facilitated through Excel. Each rater will have an independent copy of the extraction form.

Data items

For data extraction, all studies will be assigned an identification number. The following data will be extracted where available: author names, contact information for the corresponding author, publication date, country/geographic region, study objectives, sample size, population demographics (age, sex, socioeconomic status, education level, healthcare literacy, caregiver status, living environment and living arrangements), study design (type of economic evaluation, time horizon, intervention modality and model type if applicable), intervention details (design, dosage and implementation cost), comparators, economic evaluation type, costing perspective, discount rate, primary and secondary economic outcomes, primary and secondary health and effectiveness outcomes, currency, willingness to pay and assessment tools used. Primary economic outcome measures will be the incremental cost-effectiveness (i.e., cost per fall prevented), cost-utility (i.e., cost per QALY gained) and cost-benefit ratios. Mean incremental costs and mean incremental benefits will be considered secondary economic outcome measures. Primary health outcomes included will be the difference in HRQoL, derived from the initial and final HRQoL data. Secondary health outcomes will include the mean rate of falls, the mean number of falls prevented and the incidence rate ratio or risk ratio for falls. The Prevention of Falls Network Europe (ProFaNE) published a Core Outcome Set (COS) that identified given domains in randomised controlled trials and meta-analyses of falls among community-dwelling older adults.51 52 We will extract information, where available, for these five ProFaNE COS domains: falls, injuries, psychological consequences of falling, generic HRQoL and physical activity.51 52

Outcomes and Prioritisation

This review will prioritise determining the cost-effectiveness of each intervention in relation to falls prevented and QALYs gained. Analysis of participant demographics will provide insight into conditional effectiveness and target populations. Exploratory analyses will depend on data availability; they will ascertain the availability of information on social determinants of the interventions, education, healthcare literacy, family/caregiver involvement, income and living status.

Risk of bias and quality of reporting in individual studies

All studies will be assessed for quality using the Consensus on Health Economic Criteria Extended (CHEC-Extended), as this instrument is suitable for both trial and model-based economic evaluations.53 Studies reporting on 80% or greater of applicable items for their design will be considered good quality. This quality assessment will be used to synthesise narrative information. All economic evaluations will be assessed using Grading of Recommendations Assessment Development and Evaluations (GRADE) to determine the level of certainty in the evidence provided.54 Risk of bias will be assessed using the Bias in Economic Evaluation (ECOBIAS).55 56 All assessments will be completed by two independent reviewers, with any disputes resolved by a third reviewer. IRR will be calculated separately for both assessments.

Data synthesis

All data synthesis will be conducted using Excel for narrative synthesis and R for any meta-analyses. Prior to analysis, all costing data will be categorised based on perspective and living environment. All costs will be adjusted to a common year and currency using the Purchasing Power Parity and Consumer Price Indexes. In addition, all studies will be assessed for their transferability or the ability to apply information from a country of origin to other healthcare systems.57 58 This appraisal will be performed using an adapted version of a transferability checklist.59

Narrative synthesis will be conducted for all data, with delineations made along costing perspective, setting, geographical region and intervention type. Cost-effectiveness for individual studies will be based on author thresholds. Overarching cost-effectiveness for intervention groups will be based on established willingness to pay values. Data found to be comparable following a transferability assessment will be included in a global summary. Figures will be made to visualise mean, SD and 95% CIs for quantitative data.

Meta-analyses may be conducted based on the quality and availability of data. Data quality will be determined in accordance with the policies outlined in the CHEC-Extended, ECOBIAS and GRADE checklists, as defined above.53–55 Heterogeneity will be determined through the application of I2 tests and the use of transferability knock-out criteria.59 Trial-sequential meta-analyses will be applied to prevent inflation of Type I and Type II errors with each update.34 60

Additional subgroup analyses will be performed across data for intervention type, sex, age and fall history, if possible. All included subgroups have been previously correlated with increased fall risk.1 3 5 10 13 44

Meta-biases

There are no current assessments for meta-biases planned.

Confidence in cumulative evidence

Application of the GRADE checklist will be used to determine confidence in the evidence prior to publication of the base report and will be repeated for every full update.54 Ratings will be given for each intervention type relative to each costing perspective. All ratings will be done by two reviewers, with conflicts resolved by a third party.

Patient and public involvement

Patient partners will be recruited from the Falls Prevention Clinic (www.fallsclinic.ca) to provide input on review content, including areas of interest and relevant outcomes. Additional conversations on dissemination methods and research impact will be conducted throughout in the form of focus groups and will be collaboratively led by members of the research team and patient partners. Recruitment of patient partners will occur on a rolling basis to accommodate those with chronic health conditions. Clinicians, policymakers and additional stakeholders will be consulted throughout the lifespan of the review to determine how best to support the advancement of research and the creation of clinical guidelines.

Ethics and dissemination

Ethical approval will not be required as primary data will not be collected. The base copy of the review will be submitted for formal publication. Following this, updates to the review will occur based on the availability of data, with annual announcements made regarding update progress. All updates will be in the form of partial manuscripts unless the conclusions have changed to the point where a full manuscript is merited. Partial updates will be disseminated via a designated website, while full updates will seek formal publication. All updates will include a section detailing the changes made and will be accompanied by a list of new articles included.

The review has a planned lifespan of 10 years, after which continuation will be based on the certainty of the conclusions drawn and the rate of emerging evidence. In the event of a transition into retirement, a final full update will be published with a retirement notice.

The protocol and methodology of this review will undergo a formal review after 5 years to determine if revisions are necessary. If substantially altered, the protocol and corresponding PROSPERO entry will be updated and a notice will be made available via the author’s website and the next update.