Health outcomes of older patients colonized by multi-drug resistant bacteria (MDRB): a one-year follow-up study.

The objective of this study was to examine whether asymptomatic colonization with MDRB would affect outcomes in older patients one year after hospitalization in a geriatric ward. Patient samples were analyzed to identify specific MDRBs, including methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase-producing Enterobaceriaceae (ESBLE), and vancomycin-resistant enterococci (VRE). Among 337 patients screened at hospital admission, 62 (18%) carried one or more MDRB isolates (MRSA: n=23; ESBLE: n=39; VRE: n=2). At 12 months after admission, 320 patients were interviewed by telephone (17 patients lost to follow up) to assess all-cause mortality, nursing home admissions, functional decline, and hospital readmissions. All-cause mortality rates were similar in MDRB carriers (34%; n=61) and non-carriers (30%; n=259) (P=0.512). Nursing home admission, functional decline, and hospital readmission did not differ between the two groups. In this population, predictors of mortality were: male gender (P=0.002), cognitive disorders at admission (P=0.028), low pre-albumin level at admission (P=0.048), a high level of co-morbidities (P=0.002), and a history of an acute condition in the three months prior to initial hospital admission (P=0.024). In conclusion, in this cohort of older patients, asymptomatic MDRB colonization was not significantly associated with adverse health outcomes at a one-year follow-up after hospitalization. The potential limitations of the study were the small sample size, relatively high mortality rate, and lack of MDRB reassessment during the follow-up.