Introduction. Multidrug-resistant (MDR) bacterial infections are an emerging threat in older patients, but the role of global frailty, beyond age and comorbidity, has not been fully clarified. Materials and Methods. We conducted an observational study including 208 acutely hospitalized older adults. Patients were stratified into 3 groups: 1) culture-negative, 2) positive for non-multidrug-resistant bacterial infections and 3) multidrug-resistant bacterial infections. Frailty was assessed using the Clinical Frailty Scale and a multidimensional frailty index. We performed multinomial logistic regression to identify independent predictors of multidrug-resistant status. Results. Of the 208 patients, 119 (57%) were culture-negative, 60 (29%) had non-multidrug-resistant infections, and 29 (14%) had multidrug-resistant infections. Age and sex distribution were similar across groups. In contrast, frailty increased progressively from culture-negative to non-multidrug-resistant to multidrug-resistant patients: median CFS was 5, 6, and 6, respectively (p = 0.004; p for trend = 0.002), and median PC-FI was 0.20, 0.24, and 0.28 (p = 0.021). The proportion of patients with a Clinical Frailty Scale > 4 rose from 56% to 70% to 83% across the 3 groups (p = 0.015). Multidrug-resistant positive patients more frequently required professional 24-hour caregivers and broad-spectrum antibiotics and had a longer length of stay compared with the other groups. Conclusions. Frailty was more strongly associated with multidrug-resistant bacterial infections than age or traditional comorbidities.
Siniscalchi et al. (2026) studied this question.