Background and importance Polymedication is common nowadays due to an increasing aged population as well as chronic conditions. Medicines are associated with enormous health benefits but also with the potential to cause illness and death. Conversely, prescribed drugs can give a general idea of patients’ health status and their conditions.

Aim and objectives The objective of this study was to investigate if there are pharmacological factors related to hospital admissions in polymedicated elderly patients (PEP).

Material and methods An observational retrospective case–control study in a hospital influence area of 450 000 inhabitants was done. PEP (those patients taking 15 or more drugs and aged over 65 years) during November 2019 were selected. Cases were those patients who were admitted to the hospital during 2020 (SARS-CoV-2-infected patients were excluded) and controls those who did not. Studied factors were gender, age, medications (classified at ATC level 3: pharmacological subgroup and total of prescribed drugs. Odds ratios were calculated by logistic regression analysis (method backwards: Wald). SPSS (v.20) was used.

Results 930 PEP were identified in 2019 November. 128 patients were admitted to the hospital during 2020 (cases). Only 3 of 20 factors had a statistically significant (SS) result (table 1).

Conclusion and relevance In this preliminary analysis of 930 PEP, B01A (antithrombotic drugs) and a number of total prescribed drugs were SS factor associated with a higher risk of admission, meanwhile N05A (antipsychotics) showed a protective trend.

Conflict of interest No conflict of interest