(1246) Older Adult Misuse of High-risk Over-the-counter Medications: Benefits of a Pharmacy-based Intervention

Objectives: The inappropriate use of over-the-counter medications (OTC) for older adults (people at least 65 years old) is prevalent and particularly risky. OTC misuse comprises: (1) Drug-Age misuse – medication risks due to advanced age, (2) Drug-Drug misuse – medication interactions, (3) Drug-Disease misuse – contraindications with health conditions, and (4) Drug-Label misuse – deviations from label instructions, including exceeding daily or recommended single dosage, inappropriate timing, frequency, or duration of use, and use for inappropriate indications. Since pharmacies are ubiquitous sources of OTC accessibility and medication safety expertise, a pharmacy-based intervention was considered important to address OTC medication misuse. A structural redesign of pharmacy OTC aisles (i.e., Senior SafeTM) was conceptualized for the purpose of reducing OTC misuse for older adults by increasing their awareness of the risks associated with certain OTCs while also encouraging their interactions with pharmacists around these products. A central feature of Senior Safe is the use of Stop Signs for high-risk OTCs and Behind-the-Counter (BTC) Signs for particularly high-risk OTCs: Chlorpheniramine, Diphenhydramine, and Doxylamine. The Stop Signs instruct older adults to consider safer products, while BTC signage encourages them to talk to pharmacists for more informed OTC use decisions. Given the practical importance of the signage, this study’ principal aim was to determine whether Senior Safe reduced misuse of Stop Sign/BTC OTCs.

Methods: A Randomized Control Trial design was used to match and randomly allocate 20 pharmacies from a large Midwestern healthcare system to either control or intervention groups, from which 288 older adults were recruited. All study participants chose one hypothetical symptom scenario (pain, sleep, cough/cold/allergy), selected one or more OTCs, and then described how they would use those OTCs at the onset of symptoms, and then product use if symptoms persisted/worsened after initial treatment. Participants’ reported OTC use was evaluated for the four aforementioned misuse types. Misuse occurrences between intervention and control sites were compared for each misuse type using multivariate modeling, Generalized Linear Mixed Model (GLMM) analyses. For each GLMM model, participants and pharmacies were included as random factors while the five fixed factors were: intervention vs. control groups, traditional pharmacy vs. remote dispensing sites, the symptom scenarios, OTC use (at symptom onset vs. persistence), and participants’ age.

Results: Drug-Age misuse was identified in 6.8% of cases. The frequency of such misuse was significantly lower in intervention sites (Coef.=-1.012, p=.004), while pain products (Coef.=-1.192, p=.002) were less involved in misuse than cough/cold/allergy products. Drug-Drug misuse, representing the highest frequency of occurrences (20.7%) had the same effects profile as Drug-Age misuse, with intervention sites and pain products being less associated with misuse (Coef.=-1.702, p=.004; Coef.=-3.313, p<.001, respectively). For Drug-Disease (3.3%) and Drug-Label misuse (5.1%), there were too few occurrences in intervention sites for statistical comparisons. Interestingly, each misuse type was as likely to occur under both initial and persistent symptom management. It also is noteworthy that adults aged 85+ had the greatest likelihood of all misuse types.

Conclusions: These findings showcase the first multi-pharmacy intervention to demonstrate effectiveness at reducing the occurrence of various types of OTC misuse for older adults, using a rigorous statistical model-building approach. Senior Safe shows substantial benefit for reducing high-risk OTC misuse of a variety of types, which is important particularly for vulnerable adults ages 85 to 91. The results also highlight the complexity of this problem, as older adults are frequently experiencing multiple types of misuse. While there is the perception that risks are only associated with persistent OTC use, our results demonstrate that older adults misuse these medications even at symptom onset. Future research should document intervention mechanisms contributing to lower older adult OTC misuse.