Drug-Related Problems in Institutionalized Older Adults: A Cross-Sectional Study of Prevalence and Risk Factors

Aims Nursing‑home residents consume up to four times more medications than community‑dwelling older adults, making them especially vulnerable to drug‑related problems (DRPs). We quantified the prevalence of polypharmacy and DRPs in Spanish nursing homes and identified clinical factors associated with these outcomes. Main methods This observational, cross‑sectional study reviewed the pharmacotherapy of 823 residents (24 nursing homes). A systematic, structured medication review captured patient demographics, comorbidity, functional and cognitive status, number of chronic drugs and DRPs, which were classified as indication‑, effectiveness‑ or appropriateness‑related. Key findings Residents were very old (mean ± SD = 87.1 ± 7.4 years) with substantial multimorbidity, severe functional dependence and severe cognitive impairment. Chronic use of ≥10 drugs occurred in 15.0 % of residents, while 51.5 % received 5–9 drugs. At least one DRP was found in 68.3 % of residents (mean = 1.37 DRPs/patient). DRP categories were predominantly related to indication (64.7  %), followed by effectiveness (24.8 %) and appropriateness (9.8 %). Advanced age, higher comorbidity burden and polypharmacy were independent risk factors for the presence of DRPs, whereas age, comorbidity and DRPs themselves predicted polypharmacy. Significance Very old, multimorbid and heavily medicated nursing‑home residents are at particularly high risk of DRPs. Implementing routine, structured medication reviews could substantially reduce unnecessary prescribing and its associated complications in this frail population