Economic evaluations of fall prevention exercise programs: a systematic review

Introduction

One in three community-dwelling people aged over 65 years fall each year1 2 with the rate of fall-related injuries increasing with age.3 In aged care facilities, falls are a particular problem with at least 50% of residents falling each year.4 Consequences of falls include fractures and brain injuries,3 reduced quality of life,5 fear of falling, loss of confidence and self-restricted activity leading to a reduction in physical function and social interactions.6 The restriction of activities probably increases the risk of further falls by contributing to deterioration in physical capacity.

Exercise delivered as a single intervention is the most commonly investigated fall prevention intervention. Its effectiveness is supported by a recent Cochrane Review, which showed that exercise reduces the risk of falls by 23% in older adults living in the community.7 Exercise interventions are effective when delivered in a group-based setting or individually. Programmes that include balance/functional training and multicomponent programmes that target both strength and balance appear to be particularly effective.7 8 In aged care facilities, the effectiveness of exercise for preventing falls is less clear, with a 2018 Cochrane Review9 showing low-quality evidence of no effect. However, a more recent trial10 has shown promising results, with a 55% reduction in falls from a strength and balance exercise programme.

Previous systematic reviews have summarised the evidence on the cost-effectiveness of fall prevention exercise programmes, but they focused on specific population subgroups, such as adults aged>80 years11 or people with Parkinson’s Disease,12 or on fall prevention strategies more broadly rather than exercise as a single intervention.13 To date, no reviews have summarised and critically appraised the evidence on the cost-effectiveness of fall prevention exercise programmes as a single intervention for older adults living in the community and aged care facilities. Previous reviews would not have included more recent studies as the latest search was conducted in 2018 and excluded partial economic evaluations (costing studies). Costing studies can provide useful information on intervention costs that are essential for implementation. Considering the scarcity of healthcare resources and the burden posed by falls to individuals and societies, a comprehensive up-to-date review summarising the value for money of fall prevention exercise programmes would contribute to evidence-based policy and decision-making.

The aim of this review was to summarise the evidence from economic evaluations and costing studies of fall prevention exercise programmes delivered to: (1) adults aged 60+ years living in the community; (2) adults aged 60+ years living in aged care facilities. The review questions were:

What is the cost-effectiveness and cost-utility of fall prevention exercise programmes?

What are the costs of developing and implementing fall prevention exercise programmes?

Methods

This review was commissioned by the WHO Physical Activity Unit to inform the development of the WHO ACTIVE toolkits,14 which will assist countries to tailor and implement the policy recommendations outlined in the Global Action Plan on Physical Activity 2018–2030.15 This review may also support the updating of the WHO CHOICE modelling of cost-effective interventions for physical activity15 16 as part of the wider programme of CHOICE work on non-communicable disease management and prevention.

We followed the guideline recommendations for conducting systematic reviews of economic evaluations for informing evidence-based healthcare decisions17–19 and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.20 The review protocol was prospectively registered (PROSPERO 2020 CRD42020178023).

Data sources

We searched the following specialised databases and registries, which contain records of full and partial economic evaluations from inception to July 2021 (online supplemental materials 1): the National Institute for Health Research Economic Evaluation Database (via Centre for Reviews and Dissemination (CRD) up to 2015), Health Technology Assessment database (via CRD), the Tufts Cost-Effectiveness Analysis Registry, Research Papers in Economics (via EconPapers) and EconLit (Ebsco). We also searched Medline (via Ovid) and Embase from inception to July 2021. In May 2022, all searches were updated, and additional searches were conducted from inception to May in Scopus and Web of Science. We reviewed the reference lists of included papers as well as other relevant systematic reviews such as Cochrane reviews7 9 for relevant studies, and contacted experts in the field.

EligibilityType of study

We included full (cost-effectiveness, cost-utility and cost-benefit analysis) and partial (cost analysis) economic evaluations of fall prevention exercise interventions in older adults living in the community and aged care facilities to prevent falls. Both trial-based and model-based economic evaluations were included. We classified studies as trial-based analyses where all the information used to perform the economic evaluation was obtained from the trial to determine clinical effectiveness. All economic evaluations that relied on external information as a source of input for the analyses were classified as model-based, even if they only modelled the intervention using the effectiveness trial parameters, such as duration and sample size. No restrictions were applied on language, publication date or country and only peer-reviewed manuscripts and policy-relevant reports from trustworthy organisations were included.

Participants

Studies were included if they involved participants 60 years of age or older living in the community or an aged care facility.

Intervention

We only included studies where the intervention of interest was exercise that aimed to prevent falls. We excluded multifaceted interventions, where exercise was only a component of a broader intervention, as in this type of study it is not possible to quantify the effects of exercise alone.

Comparator

We included studies where an exercise intervention was compared with ‘usual care’ (ie, no change in usual activities), no intervention or a control intervention (ie, an intervention that is not thought to reduce falls, such as general health education, social visits, very gentle exercise or ‘sham’ exercise not expected to impact on falls).

Main outcomes

The health outcomes of interest were fall-related outcomes, including number of falls (or fall-related injuries, fractures or hospitalisation), and number of individuals with falls (or fall-related injuries, fractures or hospitalisation). The main health economic outcomes were incremental cost-effectiveness ratio (ICER) expressed as the incremental cost per fall prevented (or per fall-related outcomes) or incremental cost per quality-adjusted life year (QALY) gained by the intervention group compared with the comparator. Secondary outcomes were costs, such as total costs, intervention costs, health service utilisation costs, community services costs and out-of-pocket costs.

Study selection and data extraction

Two reviewers independently screened all titles and abstracts, followed by full texts, and disagreements were solved by consensus or discussion with a third reviewer. Data extraction was conducted by an experienced reviewer and all data were checked by a second reviewer. The following information was extracted into a standardised data extraction form: authors, year, journal, country, type of economic analysis, study sample characteristics, sample size, intervention and comparator description, measure of effectiveness (in terms of falls and QALYs), economic analysis perspective, type of currency, price year, time horizon, discounting, costs (total, intervention, health service utilisation, community services, out of pocket, other), ICER, sensitivity analysis and author’s conclusion. Data were extracted from the included study as well as from any other relevant publication cited in the study, such as an economic evaluation protocol or the main trial results.

We used elements of a framework for classifying physical activity programmes and services for older adults that we developed for our previous reviews for WHO21 to guide our extraction of participant characteristics and intervention description data. We used the Prevention of Falls Network Europe taxonomy to classify the exercise programmes in the included studies on the basis of the primary exercise category and noted the presence of additional, secondary, exercise categories.22 The programmes were classified as primarily involving the following exercise categories: (1) gait, balance, coordination and functional task training (referred to as ‘balance and functional exercises’ for simplicity); (2) strength/resistance training (including power training, using resistance so referred to as ‘resistance exercises’); (3) flexibility; (4) three-dimensional (3D) exercise (with tai chi or dance subcategories); (5) general physical activity (walking programmes); (6) endurance; (7) other kinds of exercise. The taxonomy allows for more than one type of exercise to be delivered within a programme. We classified programmes as multicomponent if two or more components were given equal emphasis in the intervention.

Risk of bias

Risk-of-bias assessment was conducted by two independent reviewers using the Consensus on Health Economic Criteria list (CHEC-list, online supplemental material 2)23 and any discrepancies were discussed and reviewed by a third reviewer. We created a modified version of the CHEC-list to assess the risk of bias of the costing studies (online supplemental material 3) and the final version was reviewed and approved by three authors. When rating the studies using the CHEC-list, we considered the information provided in the included study as well as from any other relevant publication cited in the study, such as an economic evaluation protocol or the main trial results.

We also rated all model-based economic evaluations considering three additional items not covered by CHEC-list items but identified by authors as relevant to the quality of the studies in the context of the present review: (1) Was the effectiveness measure used appropriate to the modelled intervention and population? Did the study that contributed the effectiveness estimate investigate a population and exercise intervention with similar characteristics to that being modelled? (2) Did the model appropriately consider attenuation of effectiveness on falls, post intervention? Was any evidence used to support the continued effectiveness of the intervention beyond the trial duration? (3) Did the study report intermediate measures or use a ‘stepped approach’ to report the results of each step of the model to allow understanding of the impact of each step on the overall results?

For the trial-based economic evaluations, we considered the methodological quality of the effectiveness trial used to conduct the economic evaluation by using the Physiotherapy Evidence Database (PEDro) scale.24 25 The PEDro scores publicly available in the PEDro database (www.pedro.org.au) were used.

Strategy for assessing the certainty of economic evaluations for WHO decision-making

We developed a rating scale to assess the overall certainty of the model-based economic evaluations based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) principles26 as well as previous recommendations for assessing the certainty of evidence from modelling studies.27 The risk-of-bias assessment items (extended CHEC-list) and the three additional items were integrated in our certainty of evidence assessment and the following domains were considered for model-based economic evaluations: (A) quality of model reporting, (B) certainty of model inputs, (C) credibility of model, (D) certainty of model outputs, (E) directness of model (online supplemental material 4).

For the trial-based economic evaluations, in addition to the risk-of-bias assessment (CHEC-list items), we considered the methodological quality of the effectiveness trial used as input for the economic evaluation (PEDro items 2, 4 and 8) to assess the certainty of the evidence (online supplemental material 5). The following domains were considered for trial-based economic evaluations: (A) quality of trial-based economic evaluation reporting, (B) credibility of the clinical trial, (C) credibility of economic evaluation, (D) certainty of economic evaluation results, (E) applicability. Each domain was rated as ‘good’, ‘fair’ or ‘poor’ and the level of certainty of each economic model for WHO decision-making was rated as high, moderate, low or very low considering the ratings for the domains.

Strategy for data synthesis

Results were not pooled as the studies were heterogeneous in their intervention, methods, data and context. Instead, we presented a narrative synthesis of the findings from included studies. Summaries of effect size, cost-effectiveness and costs were reported for each study (as available). Summary tables and figures are also provided. We used an arbitrary willingness-to-pay threshold of US$100 000 per QALY gained and US$4000 per fall prevented to assist with the interpretation of results.28

Studies reported costs in different currencies and from different years. To enable comparison of findings, we expressed monetary values in two ways: (1) by year and currency as reported by the included study, (2) converted to 2020 US$. We initially inflated the costs to year 2020 using the inflation rate for each country according to inflation rates from theOrganisation for Economic Co-operation and Development (OECD) database (https://data.oecd.org/price/inflation-cpi.htm). Then we transformed the costs in respective currencies of 2020 into US$ using purchasing power parity conversion factors for 2020 (https://data.oecd.org/conversion/purchasing-power-parities-ppp.htm).

Discussion

There are a considerable number of economic evaluations of fall prevention exercise programmes for people living in the community (n=20, reported in 21 articles), but none were conducted in low-income or middle-income countries. Overall, there was heterogeneity in the economic analyses investigated, making direct comparisons difficult. The results varied, with ICER estimates ranging from dominant (more effective and less costly) to as high as US$279 802 per QALY gained and US$11 986 per fall prevented. A considerable proportion of the interventions (17 out of 24, 71%) had an ICER below a willingness-to-pay threshold of US$100 000 per QALY gained. The level of certainty varied between low and moderate, but there was a considerable number of studies with moderate level of certainty (n=11). These results suggest that fall prevention exercise programmes probably offer good value for money depending on one’s willingness to pay, particularly for ‘older’ old people (aged 80+ years) and those with high fall risk. There was a trend for more favourable results for supervised exercise. In contrast, there are few economic evaluations (n=2) investigating fall prevention exercise programmes for older adults living in aged care facilities. The results of these economic evaluations are promising, with relatively low ICERs for fall avoided (dominant and US$35/fall avoided) and moderate level of certainty for the trial-based analysis. None of the included studies conducted in care facilities investigated QALYs. The overall evidence in this setting is less clear, and more high-quality trial-based and model-based analyses are needed. The intervention costs varied across the included economic analyses and are similar to costs found in previous reports of fall prevention exercise.59

Implications for clinicians and policy-makers

Although our results suggest that exercise programmes may offer better value for money for specific subgroups (‘older’ old people, people with higher fall risk) and this information could inform budget allocation, we argue that fall prevention exercise should be offered to all older adults given its proven benefits for fall reduction.7 Although a trend was found for multicomponent and tai chi exercises and supervised programmes to offer better value for money than balance and functional exercise and unsupervised programmes, these results should be interpreted with caution. Therefore, policy-makers and managers considering funding exercise programmes should choose the exercise type and supervision level according to their context and budget.

We have selected an arbitrary willingness-to-pay threshold of US$100 000 per QALY gained to facilitate the interpretation of findings. Although this threshold has been commonly referenced in the US literature,28 whether an intervention is cost-effective or not depends on the decision-maker’s willingness to pay. Decision-makers considering implementing a fall prevention exercise programme should also take into account the additional benefits of physical activity for overall health60 that were not included in the economic evaluations, low risk as well as the ease of implementation of the intervention (ie, no sophisticated equipment required and no need for the highly specialised workforce).

The overview of the intervention costs presented in this review should be interpreted in the context of the duration of the exercise programme, level of supervision and number of participants. Policy-makers and governments considering the implementation of a fall prevention exercise programme can use this information to inform their budget and implementation planning. The intervention cost information can also be used as an input for future model-based analyses.

None of the included studies were conducted in low-income and middle-income countries. However, most of the model-based analyses used effectiveness measures from meta-analyses that included some studies conducted in low and middle-income countries. Considering the ease of implementation of falls prevention exercise programmes, we would expect to find similar cost-effectiveness ratio in countries with lower income levels. This needs to be tested in future studies.

Strengths and limitations

This is the largest systematic review of economic evaluations and costing studies of fall prevention exercise programmes and the first to include both community and aged care settings. This was also the first review to attempt to explore the results according to participant and programme characteristics, to summarise intervention costs, to conduct an in-depth appraisal of the risk of bias of the studies and to apply GRADE style rating to assess the certainty of the evidence. Our results are aligned with previous reviews that concluded that fall prevention programmes for older people living in the community are likely to offer good value for money,13 29 although it was often unclear the methods and criteria used to judge an intervention as cost-effective in these previous reviews.

The following limitations should be considered when interpreting the results of this study. Although we used a comprehensive search strategy and searched specialised databases, we only searched electronic databases and performed hand search of peer-reviewed systematic reviews. It is possible that we may have missed economic evaluations of fall prevention exercise programmes that were not available in these sources. As anticipated, we were unable to pool the results by conducting a meta-analysis. There are often inherent challenges in comparing and combining the results of economic evaluations as they commonly have several differences, such as context and health service of the country, perspective, time horizon, cost items considered, methods for capturing costs and for calculating ICERs. We attempted to facilitate comparability between studies by reporting results in 2020 US$ and by displaying the results in figures. However, such approach has limitations as it does not consider the underlying heterogeneity between the studies. Additionally, uncertainty intervals were not displayed in the figures as these were rarely reported in the included studies. Therefore, caution is needed when interpreting the results of the figures and they should be analysed in combination with the detailed information provided for each study in the online supplemental tables and materials. There may be a risk of publication bias. There is presently no clear method to assess publication bias in reviews of economic evaluations as economic evaluation protocols are commonly not registered and trial-based economic evaluations should only be performed for interventions that are effective.

Several studies only reported results for natural outcomes (ie, fall-related outcomes). These results are useful when comparing interventions with the same outcome measure. However, natural outcomes do not allow us to examine whether the intervention represents value for money relative to other disparate healthcare programmes. A willingness-to-pay threshold for fall-related outcomes is currently not available in the literature, which makes the interpretation of results more challenging. Previous non-exercise fall prevention strategies, such as home safety programmes and multifactorial interventions have demonstrated similar results to the ones found in this review.13 29

Although we found that supervised programmes seem to offer better value for money than unsupervised programmes, these results should be interpreted with caution as social interactions in supervised programmes may contribute to the results of exercise interventions. However, as social interaction is a key component of supervised exercise it is not possible to disentangle the proportion of the effect observed that is due to the exercise programme itself or social interactions associated with the programme.

Recommendations for future research

Future economic evaluations of fall prevention exercise programmes should describe both alternatives in details, including the type of exercise, frequency, duration, as well as provide a detailed description of the control intervention as the content of the control intervention will influence the interpretation of results. Additionally, studies should report disaggregated values, that is, total costs per group, incremental costs and incremental outcomes, instead of only presenting ICERs, as the additional information would enhance the interpretation of findings. Studies should also express the uncertainty in the results by reporting uncertainty intervals and acceptability curves.

Future modelled economic evaluations should identify all relevant costs for both alternatives, clearly report the parameters used as well as their sources and report uncertainty intervals for the results. Additionally, extensive sensitivity and scenario analyses should be performed to test the robustness of the findings and to enhance interpretation of results. Farag et al’s study could be used as an example.42 In this model-based analysis, different intervention costs, uptake levels and programme effectiveness were modelled in sensitivity analyses and, therefore, the results offer clear guidance to policy-makers considering implementing a fall prevention programme. In addition to reporting the results for the end of the time horizon, authors should also report intermediate results in a stepped manner so the impact of each of the steps of the model can be tested. Examples of intermediate results include results limited to trial-based data, results after application of utility weights, and extension of time horizon.

Future studies should consider using standardised methods for identifying and measuring costs and health benefits to enhance comparability of results. Additionally, they should present a detailed breakdown of the elements and costs involved in developing and implementing a fall prevention programme, such as training, staff and equipment to allow implementation. Unit costs should also be presented for each of these items. Actual intervention costs should be reported instead of costs based on recommendations for future applications, which could be explored in a scenario analysis.

Most of the trial-based economic evaluations included in this review only included fall-related healthcare utilisation. Future studies should consider including total healthcare utilisation as exercise may have additional consequences that are not captured by the fall-related healthcare utilisation measure. For instance, exercise may result in other general health benefits and therefore reduce other service utilisation that is not related to a fall. On the other hand, exercise may have unintended consequences and may increase the incidence of adverse events requiring medical attention that are not related to falls, such as musculoskeletal complaints. Therefore, capturing healthcare utilisation more broadly would offer a more comprehensive picture of the cost-effectiveness of the intervention.

Future primary studies investigating the effectiveness of fall prevention exercise programmes should consider including a trial-based economic evaluation, particularly those conducted in low-and-middle-income countries. Studies should also consider including a generic outcome measure such as QALY to enhance comparability with other interventions. We strongly recommended that future primary studies and reviews follow standard economic evaluation best-practice recommendations17–19 and reporting guidelines, such as the Consolidated Health Economic Evaluation Reporting Standards statement.61

Conclusions

This review found a considerable number of economic evaluations (n=20, 11 of moderate certainty) investigating the value for money of fall prevention exercise programmes for older adults living in the community. The results of the economic evaluations varied, which probably reflects the heterogeneity between studies, with differences in the perspective taken, time horizon, healthcare systems between countries, which in turn influences the cost consideration. However, for many of the studies, there is an indication of significant potential for cost-effectiveness of fall prevention exercise programmes. The intervention appeared to be more cost effective for ‘older’ old people (eg, 80+) and those with high fall risk. The evidence for older adults living in aged care facilities is limited but promising. The intervention costs varied, and no clear association was found between costs and type of exercise, location and level of supervision. The intervention costs summarised in this report should be interpreted considering exercise type, duration, level of supervision and number of participants. This information can be used for planning the implementation of future programmes or future models investigating the value for money of such programmes.

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