Liao PJ, et al. - Among 108,548 older inpatients, researchers examined factors correlated with the occurrence of adverse drug reactions (ADR), prognosis, and medical expenses in this nested case-control study. The admission department, number of comorbidities, and number of drug prescriptions before ADRs were linked to ADR occurrence in this older population. The investigators noted that ADR severity was a significant prognostic factor among ADR cases. The number of comorbidities and polypharmacy—including the use of psychoactive drugs—had significant effects on ADR occurrence and prognosis, according to findings. Furthermore, ADRs resulted in the addition of US$1803.8, US$360.8, and 5.6 days in total medical expenses, drug expenses, and length of stay among affected older inpatients, respectively. The findings may inform future modification of prescription and improvement of patient safety in geriatric care.