Polypharmacy and socioeconomic inequalities in Portugal, 2015–2022: a SHARE cross-sectional study

Background

Polypharmacy is a major challenge in ageing populations and may reflect both clinical need and social vulnerability. Evidence on socioeconomic inequalities in polypharmacy in Portugal remains limited.

Methods

We conducted a repeated cross-sectional study using SHARE Portugal waves 6 (2015), 7 (2017) and 9 (2022). Participants aged 50–89 years with complete information were included (n = 3,645 person-wave observations: 1,334 in 2015, 1,020 in 2017 and 1,291 in 2022). Polypharmacy was defined as taking ≥5 different medicines on a typical day. Socioeconomic exposures were education, difficulty making ends meet and living alone. Logistic regression models were estimated separately by wave, adjusting for age, sex, multimorbidity and self-rated health.

Results

Preliminary unweighted polypharmacy prevalence was 38.5% in 2015, 41.4% in 2017 and 40.0% in 2022. Polypharmacy was more frequent among women, those with lower education, those living alone and those reporting greater economic difficulty. Participants with great difficulty making ends meet had consistently higher polypharmacy prevalence than those without relevant difficulty (47.1% vs 33.3% in 2015; 49.8% vs 36.3% in 2017; 49.4% vs 34.2% in 2022). In fully adjusted logistic models, great economic difficulty remained associated with polypharmacy in all waves (aOR=1.82, 95%CI 1.32–2.52 in 2015; aOR=1.51, 95%CI 1.06–2.15 in 2017; aOR=1.96, 95%CI 1.40–2.75 in 2022). Education and living alone were not independently associated after adjustment. Multimorbidity showed the strongest association (aOR range: 4.06–4.50).

Conclusions

Polypharmacy was common and stable over time in this preliminary analysis. Economic hardship, more than education or living alone, was the socioeconomic factor most consistently associated with polypharmacy. Medication review and pharmaceutical policy should explicitly consider economic vulnerability when addressing safe and equitable prescribing in ageing populations.

Key messages

• Polypharmacy affected about 40% of Portuguese SHARE participants aged 50–89 between 2015 and 2022.

• Great economic difficulty was consistently associated with polypharmacy after adjustment for age, sex and health.