Objective: To determine whether treatment of symptomatic bacteriuria in older ambulatory women affects the subsequent development of symptoms of urinary tract infection.
Design: A controlled clinical trial.
Participants: Older women not having urinary catheters.
Measurements: Urine cultures every 6 months (the same organism at 10(5) colony-forming units or more per mL on two midstream urine specimens defined asymptomatic bacteriuria) and questionnaire surveys for the new development of symptoms of urinary tract infection (dysuria, frequency, urgency, low back pain with fever) 1, 3, and 6 months after the initial survey.
Results: Of the 23 initially culture-positive participants receiving antibiotic treatment for symptomatic bacteriuria, nine were culture positive at 6 months, which contrasts with 18 of 27 who received no treatment or placebo, P = .05. However, symptoms of urinary tract infection were more common in the antibiotic-treated group.
Conclusion: Antibiotic therapy effectively reduced the subsequent occurrence of positive urine cultures, but symptoms were not reduced. Based on this study of morbidity, previous studies failing to show any relation to mortality, and the cost and complications of antibiotic therapy in the older population, treatment of asymptomatic bacteriuria in older women is contraindicated.