Characterising polypharmacy in the very old: Findings from the Newcastle 85+ Study

Abstract

Background Polypharmacy is potentially harmful and under-researched amongst the fastest growing subpopulation, the very old (aged ≥85). We aimed to characterise polypharmacy using data from the Newcastle 85+ Study—a prospective cohort of people born in 1921 who turned 85 in 2006 (n = 845). Methods The prevalence of polypharmacy at baseline (mean age 85.5) was examined using cut-points of 0, 1, 2–4, 5–9 and ≥10 medicines—so-called ‘no polypharmacy’, ‘monotherapy’, ‘minor polypharmacy’, ‘polypharmacy’ and ‘hyperpolypharmacy.’ Cross-tabulations and upset plots identified the most frequently prescribed medicines and medication combinations within these categories. Mixed-effects models assessed whether gender and socioeconomic position were associated with prescribing changes over time (mean age 85.5–90.5). Participant characteristics were examined through descriptive statistics. Results Complex multimorbidity (44.4%, 344/775) was widespread but hyperpolypharmacy was not (16.0%, 135/845). The median medication count was six (interquartile range 4–8). Preventative medicines were common to all polypharmacy categories, and prescribing regimens were diverse. Nitrates and oral anticoagulants were more frequently prescribed for men, whereas bisphosphonates, non-opioid analgesics and antidepressants were more common in women. Cardiovascular medicines, including loop diuretics, tended to be more frequently prescribed for socioeconomically disadvantaged people (<25th centile Index of Multiple Deprivation (IMD)), despite no difference in the prevalence of cardiovascular disease (p = 0.56) and diabetes (p = 0.92) by IMD. Conclusion Considering their complex medical conditions, prescribing is relatively conservative amongst 85-year-olds living in North East England. Prescribing shows significant gender and selected socioeconomic differences. More support for managing preventative medicines, of uncertain benefit, might be helpful in this population.