Publication:

A prospective cohort study to evaluate the correlates of polypharmacy and its association with depression among elderly patients

Background Polypharmacy is a reliable indicator of irrational prescribing particularly among elderly. Polypharmacy increases the risk of adverse drug reactions (ADRs) exponentially imposing higher economic burden. Addressing and evaluating the prescribing practices in elderly will rationalize the drug utilization leading to improvement in quality of health care. The present study was taken to evaluate the determinants of polypharmacy and its association with depression, defined as a 15 item geriatric depression scale (GDS) >6, in elderly patients.

Methods This prospective cohort study was conducted at department of medicine, Victoria hospital, Bengaluru 100 patients aged 60 and above years was enrolled. Relevant data regarding patients’ demographic details, smoking and alcohol consumption, medical diagnosis and drug details were collected. Geriatric Depression Scale was used to diagnose depression.

Results Out of 100 patients screened, 36% were males and 64% were females. Polypharmacy was noted in 73% of the elderly, of which 43% had cumulative co morbidity (≥4 diagnoses).  68% were found to have a GDS score of ≥6, which corresponded to Depression. Patients with depression (GDS score ≥6) had 1.54 (OR-1.54, 95% CI-0.59-4.01) times more risk of encountering polypharmacy (≥4 drugs). Cumulative co-morbidity (OR-1.52, 95% CI-1.08–2.11, p <0.05) was identified as an independent correlate of polypharmacy.

Conclusions Increasing age, males, Cumulative comorbidity of ≥4 diagnoses and geriatric depression were found to be the positive correlates of polypharmacy in elderly. Though geriatric depression increases the odds of encountering polypharmacy, it does not affect drug consumption directly; rather it is an important index of cumulative co-morbidity which influences polypharmacy significantly.