Evaluating the sustained effectiveness of a novel pharmacy-based intervention to reduce older adult misuse of over-the-counter medications: A case for non-significance.

Introduction: Misuse of over-the-counter (OTC) medications by older adults (age 65+) can comprise Drug-Age, Drug-Drug, Drug-Disease, and Drug-Label types. Pharmacies in the United States are prevalent sources of OTCs and are an apt setting to address OTC misuse. Senior Safe™ is a pharmacy-system redesign for preventing older adult OTC misuse. The redesign uses signage to designate high-risk OTCs and safer products for older adult use, as well as prompting older adults to engage with pharmacy staff around medication safety issue.

Objectives: This study compared misuse in pharmacies with initial Senior Safe implementation (Immediate Effects group) to pharmacies with Senior Safe after 3 months (Sustained Effects group).

Methods: A non-equivalent group design, involving older adults recruited from matched and randomly-allocated pharmacy sites within a health system, compared the Immediate Effects (n = 83) and Sustained Effects (n = 65) groups. All participants were recruited outside the pharmacy and were given hypothetical symptom scenarios from which to choose (i.e., cough/cold/allergy, pain, or sleep). Participants were then asked to select an OTC to treat that symptom, and explain their OTC use at symptom onset and if symptoms persisted/worsened. Participants' reported OTC use was evaluated for each misuse type. Multivariate modeling estimated differences in misuse between the Immediate and Sustained Effects groups.

Results: No significant differences emerged between Immediate and Sustained Effect groups for any misuse type for which statistical modeling was conducted. Drug-Age misuse was statistically less likely for sleep products (OR = 0.170, p = .005) and for adults aged 85+ when compared to the 65-74 and 75-84 age categories (OR = 3.979, p = .053; OR = 6.900, p = .031, respectively).

Conclusions: These non-significant results suggest that the intervention effect was maintained at three months. Overall, then, misuse reductions occurring immediately after intervention implementation did not significantly increase after three months. System buy-in, including assessing costs to implement and maintain Senior Safe, is critical to promote broader adoption.