“Shotgun” Versus Sequential Testing

Background: Although vaginitis is a common outpatient problem, only 60% of patients can be diagnosed at the initial office visit of a primary care provider using the office procedures of pH testing, whiff tests, normal saline, and potassium hydroxide preps. Objective: To determine the most cost‐effective diagnostic and treatment approach for the medical management of vaginitis. Design: Decision and cost‐effectiveness analyses. Participants: Healthy women with symptoms of vaginitis undiagnosed after an initial pelvic exam, wet mount preparations, pH, and the four criteria to diagnose bacterial vaginosis. Setting: General office practice. Methods: We evaluated 28 diagnostic strategies comprised of combinations of pH testing, vaginal cultures for yeast and Trichomonas vaginalis , Gram's stain for bacterial vaginosis, and DNA probes for Neisseria gonorrhoeae and Chlamydia. Data sources for the study were confined to English language literature. Measurement: The outcome measures were symptom‐days and costs. Results: The least expensive strategy was to perform yeast culture, gonorrhoeae and Chlamydia probes at the initial visit, and Gram's stain and Trichomonas culture only when the vaginal pH exceeded 4.9 ($330, 7.30 symptom days). Other strategies cost $8 to $76 more and increased duration of symptoms by up to 1.3 days. In probabilistic sensitivity analysis, this strategy was always the most effective strategy and was also least expensive 58% of the time. Conclusions: For patients with vaginitis symptoms undiagnosed by pelvic examination, wet mount preparations and related office tests, a comprehensive, pH‐guided testing strategy at the initial office visit is less expensive and more effective than ordering tests sequentially.