Medication use among community-dwelling older Icelanders. Population-based study in urban and rural areas

Objective: To describe medication use among older community-dwelling Icelanders by collecting information on number of medicine, polypharmacy (>5 medications), and medications by ATC categories. Moreover, to explore the relationship between medication use and various influential factors emphasizing residency in urban and rural areas. Material and methods: Population-based, cross-sectional study. Participants were randomly selected from the National registry in one urban (n=118) and two rural (n=68) areas. Inclusion criteria: 1) >= 65 years old, 2) community-dwelling, 3) able to communicate verbally. Information on medication use was obtained from each person's medication list and interviews. A questionnaire and five standardized instruments were used to assess the potential influencing factors. Results: On average, participants used 3.9 medications and prevalence of polypharmacy was 41%. Men used 3.5 medications on average and women 4.4 (p=0.018). Compared to rural residents, urban residents had fewer medical diagnoses, better mobility, less pain, and fewer depressive symptoms. By controlling for the effects of these variables, more medications were associated with urban living (p<0.001) and more medical diagnoses (p<0.001). Likewise, adjusted odds for polypharmacy increased with urban residency (p=0.023) and more medical diagnoses (p=0.005). Urban residency, more medical diagnoses, higher age, and male gender were related to use of drugs for blood and blood forming organs. Conclusion: The results reveal an unexplained regional difference in medications use by older Icelanders. Further studies are required on why urban residents use at least equal amount of medications as rural residents despite better scores on health assessments.