Antibiotic prescribing and outcomes following treatment of symptomatic urinary tract infections in older women

OBJECTIVE: To describe antibiotic prescribing patterns for the treatment of urinary tract infections (UTI) among older women female long-term care facility residents and evaluate factors associated with adverse outcomes METHODS: Study Design: Population-based retrospective cohort study. Population and sampling frame: All female residents of Olmsted County, Minnesota, aged 65 years and older, who were treated for urinary tract infections during calendar year 1996 were included in the study. Data collection: Subjects' complete medical records were reviewed and abstracted. Data collected included age, weight, serum creatinine, antibiotic treatment including dosage and duration, as well as retreatment and adverse drug events. RESULTS: A total of 196 subjects, ranging in age from 65 to 98 years, were diagnosed with UTI during calendar year 1996. Forty-four subjects were nursing home residents, and 152 resided in the community. The odds of prolonged antibiotic therapy (7 days or more) were 83 times higher among nursing home residents (Odds ratio = 82.7, 95% Confidence Interval, 11.1-617.7). The odds of receiving treatment for 10 days or longer were 5 times higher among nursing home residents compared to community subjects. The odds of underlying renal impairment necessitating dosage reduction were 3.6 times higher among nursing facility residents. Nursing facility residents were 7.3 times more likely to be treated with excessive dosages of antibiotics, 9.6 times more likely to experience adverse drug events, and 2.6 times more likely to receive retreatment for persistent or recurrent symptoms within one week of antibiotic discontinuation, compared to community subjects with UTI. CONCLUSIONS: Nursing home residents with UTI are treated for longer durations than community elderly. They experience a greater likelihood of receiving antibiotics in excessive dosage, a greater likelihood of adverse drug events, and a greater likelihood of retreatment compared with community subjects with UTI.