EVALUATION OF SUSPECTED URINARY-TRACT INFECTION IN AMBULATORY WOMEN -A COST-UTILITY ANALYSIS OF OFFICE-BASED STRATEGIES

BACKGROUND, The purpose of this study was to determine the most cost-e ffective strategy for managing suspected urinary tract infections in o therwise healthy adult women presenting to their primary care physicia n with dysuria and no symptoms or signs of pyelonephritis. Several off ice-based management strategies are considered: empiric therapy, use o f dipstick analysis, use of complete urinalysis, and several strategie s using office or laboratory cultures, METHODS. We constructed a decis ion tree using model probabilities obtained from the literature. Where published probabilities were unavailable, we used extensive sensitivi ty analyses. Utilities were obtained from the Index of Well-Being. We obtained costs by surveying hospitals, physicians, and pharmacies. RES ULTS. The most cost-effective strategy is to treat empirically ($71.52 per quality-adjusted life month, QALM). When the cost of antibiotics exceeds $74.50 or if the prior probability of having a UTI is under 0. 30, then treatment guided by the results of a complete urinalysis is p referred. While it was the preferred strategy, other strategies (compl ete urinalysis, culture and treat, and dipstick testing only) were ass ociated with greater utility, The marginal cost-effectiveness of these strategies compared with empiric therapy ranged from $2964 to $48,460 per additional QALM, CONCLUSIONS. The preferred strategy of empiric t herapy is robust over a wide range of sensitivity analyses, While empi ric therapy is associated with the best cost-utility ratio, doing a cu lture yields the greatest utility at greater incremental cost per QALM . Many primary care physicians already treat UTls empirically with ant ibiotics. This study confirms that empiric therapy, while frowned upon by some, is a cost-effective strategy. Other strategies may be consid ered, but at greater marginal cost. Ultimately these findings need to be confirmed in clinical trials.