Researchers followed up on a previously published report of a randomized controlled trial of a fall-prevention intervention. Linking trial data to Medicare claims, they considered whether the intervention reduced health care costs or the frequency of emergency department visits for fall-related injuries. They used these objectively measured outcomes to provide an overall assessment of the intervention's effectiveness.

Evaluation of an Intervention to Prevent Falls

Daniel A. Waxman, Xiaoyu Nie, Asa Wilks, David A. Ganz

ResearchPublished Oct 26, 2016

The Office of the Assistant Secretary for Planning and Evaluation (ASPE) in the U.S. Department of Health and Human Services asked the RAND Corporation to evaluate the effectiveness of an intervention designed to prevent falls in the elderly, with a particular focus on fall-related injuries and on health care costs.

Researchers linked data collected during a randomized trial to Medicare enrollment and claims files to compare health care costs and the frequency of fall-related emergency department (ED) visits between treatment and control groups. Using claims from both before and after trial enrollment, they adjusted for baseline differences and used intention-to-treat analyses, thereby overcoming limitations inherent in the outcome data collected during the trial.

The researchers did not find a statistically significant effect of the intervention on costs or on the rate of fall-related ED visits. They estimate that the intervention was associated with an $18-per-month increase (95-percent confidence interval [CI] = –$94 to $130) in total health care spending, an $18-per-month increase (95-percent CI = –$12 to $48) for care directly related to injuries, and a 4-percent increase in the risk of falls (95-percent CI = 26-percent decrease to 43-percent increase).

The researchers concluded that the fall-prevention intervention did not have a substantial effect on health care costs. Although they did not find evidence that the intervention reduced ED visits for fall-related injuries, they cautioned that the study was underpowered for this outcome and that a clinically meaningful effect could have gone undetected.

Key Takeaways

The Intervention Did Not Substantially Affect Costs

  • No statistically significant effect on costs was detected.
  • The 95-percent confidence interval for the intervention's effect on total monthly Medicare costs ranged from a $94-per-month decrease to a $130-per-month increase.
  • The 95-percent confidence interval for the intervention's effect on direct injury–related Medicare costs ranged from a $12-per-month decrease to a $48-per-month increase.

Researchers Did Not Detect an Effect on the Frequency of ED Visits for Fall-Related Injuries

  • No statistically significant effect on fall-related ED visits was detected.
  • The 95-percent confidence interval for the estimated effect of the intervention on the incidence of fall-related injuries leading to ED visits ranged from a 26-percent reduction to a 43-percent increase (i.e., an incidence rate ratio of 0.74 to 1.43). The wide range of this estimate suggests that the study was underpowered for this outcome and that a clinically meaningful effect could have gone undetected.

Researchers Developed and Validated a Model That Can Be Used to Measure the Incidence of Fall-Related ED Visits Without Relying on External Cause-of-Injury Codes

  • The model assigns each ED visit a probability weight that represents the likelihood that the visit was precipitated by a fall.
  • The weights can be summed to measure the incidence of fall in a given population and time interval. They can also be used to determine the incidence of particular fall-related injuries of interest by summing the weights for ED visits during which particular injuries were diagnosed.

Recommendations

  • For future evaluations of interventions aimed at preventing fall-related injuries, study outcomes derived from Medicare claims offer several advantages over self-reported data. Their primary disadvantage is that, at present, claims are available only for beneficiaries enrolled in fee-for-service Medicare. Advantages of claims-based outcomes include that they are not subject to recall bias, they allow for measurement of baseline differences in costs or the incidence of fall-related injuries, and they allow for intention-to-treat analyses. Because claims-based outcomes can be measured without costly follow-up calls, such outcomes might facilitate larger-scale studies of population-based interventions.
  • When the goal is to use health care claims as a surrogate for measuring whether or not a fall-related injury occurred, either direct injury-related costs or the estimated rate of falls might be better measures than total costs.
  • Cost-effectiveness analyses that consider not only health care costs but also improvements in health could be an important step in understanding the value of these interventions.

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Waxman, Daniel A., Xiaoyu Nie, Asa Wilks, and David A. Ganz, Evaluation of an Intervention to Prevent Falls. Santa Monica, CA: RAND Corporation, 2016. https://www.rand.org/pubs/research_reports/RR1649.html.
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The research described in this report was sponsored by the Assistant Secretary for Planning and Evaluation (ASPE) and conducted by RAND Health.

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