Background and importance Polymedication is one of the most important problems facing healthcare professionals in Europe today.

Aim and objectives To analyse adherence in polymedicated elderly patients and its relationship with the number of drugs prescribed.

Material and methods Cross-sectional observational study, carried out between February and May 2021 in the Traumatology area of a tertiary hospital. Patients >75 years old, multi-pathological (≥2 chronic pathologies) and polymedicated (≥5 chronic medications) were included. We excluded those with whom we were unable to communicate, due to their physical/mental condition and absence of a companion.

The clinical history was reviewed, collecting anthropometric variables, pathologies and home medication, confirmed by a personal interview.

Adherence to treatment was measured using the Morisky–Green questionnaire, which consists of four dichotomous yes/no questions to obtain information on patient compliance. Adherence was related to the number of drugs prescribed.

The Shapiro–Wilk normality test and the non-parametric Mann–Whitney U test were used for statistical analysis. Results with p values <0.05 were considered significant.

Results 48 patients were selected, 76.2% female; mean age was 83.8±5.4 years.

The mean number of pathologies/patient was 6±2.6. 61.9% of patients had five or more diseases. The most frequent health problems were hypertension (66.7%), hypercholesterolaemia (42.8%), diabetes mellitus (33.3%) and depression (33.3%). The mean number of medications/patient was 9±3.4. 35.7% of patients were highly polymedicated (≥10 medications).

The Morisky–Green test showed that 82.5% were adherent to treatment. 22.5% of patients were not taking ≥2 prescribed and necessary medications. In addition, 36.6% were found to self-medicate.

No statistically significant relationship was found between the number of medications and adherence (p=0.8).

Conclusion and relevance Contrary to other recently published studies, adherence was good in our sample and was not related to the number of medications. The first finding may be related to the fact that many patients had caregivers who took care of their medication.

This study shows that a significant proportion of the population is self-medicating. This calls for closer monitoring by community pharmacists, with patient education and collaboration with hospital pharmacists, whose easy access to medical records can help to conduct studies on the prevalence of polymedicated patients and the appropriateness of their prescriptions.

Conflict of interest No conflict of interest