Change in central nervous system-active medication use following fall-related injury in older adults

Abstract

Background: Central nervous system (CNS)-active medication use is an important modifiable risk factor for falls in older adults. A fall-related injury should prompt providers to evaluate and reduce CNS-active medications to prevent recurrent falls. We evaluated change in CNS-active medications up to 12 months following a fall-related injury in community-dwelling older adults compared with a matched cohort without fall-related injury.

Methods: Participants were from the Adult Changes in Thought study conducted at Kaiser Permanente Washington. Fall-related injury codes between 1994 and 2014 defined index encounters in participants with no evidence of such injuries in the preceding year. We matched each fall-related injury index encounter with up to five randomly selected clinical encounters from participants without injury. Using automated pharmacy data, we estimated the average change in CNS-active medication use at 3, 6, and 12 months post-index according to the presence or absence of CNS-active medication use before index.

Results: One thousand five hundred sixteen participants with fall-related injury index encounters (449 CNS-active users, 1067 nonusers) were matched to 7014 index encounters from people without fall-related injuries (1751 users, 5236 nonusers). Among CNS-active users at the index encounter, those with fall-related injury had an average decrease in standard daily doses (SDDs) at 12 months (-0.43; 95% CI: -0.63 to -0.23), and those without injury had a greater (p = 0.047) average decrease (-0.66; 95% CI: -0.78 to -0.55). Among nonusers at index, those with fall-related injury had a smaller increase than those without injury (+0.17, 95% CI: +0.13 to +0.21, vs. +0.24, 95% CI: +0.20 to +0.28, p = 0.005).

Conclusions: The differences in CNS-active medication use change over 12 months between those with and without fall-related injury were small and unlikely to be clinically significant. These results suggest that fall risk-increasing drug use is not reduced following a fall-related injury, thus opportunities exist to reduce CNS-active medications, a potentially modifiable risk factor for falls.

Keywords: fall-related injury; medications; older adults.

Figure 1.

At index (yellow oval) and each follow-up time point (blue ovals), central nervous system (CNS)-active medication use was defined as having any prescription fill coverage overlapping with the period 30 days prior to each time point (dotted line in figure). This measure takes into account adherence and early refills. The green bars in the box below show three different example scenarios of prescription fills: 1) the medication fill is completed prior to the 30 day window which is considered not current use; 2) the medication fill overlaps the 30 day window which is considered current use; and 3) the medication fill starts within the 30 day window which is considered current use.