"Shotgun" versus sequential testing. Cost-effectiveness of diagnostic strategies for vaginitis.
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.


METHODS
Decision and cost-effectiveness analyses.


METHODS
Healthy women with symptoms of vaginitis undiagnosed after an initial pelvic exam, wet mount preparations, pH, and the four criteria to diagnose bacterial vaginosis.


METHODS
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.


METHODS
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 dollars, 7.30 symptom days). Other strategies cost 8 dollars to 76 dollars 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.
Carr
Phyllis L
PL
Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA. plcarr@bu.edu
Rothberg
Michael B
MB
Friedman
Robert H
RH
Felsenstein
Donna
D
Pliskin
Joseph S
JS
D000328:Adult; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002690:Chlamydia Infections / Q000175:diagnosis / Q000191:economics; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D015342:DNA Probes / Q000191:economics; D003661:Decision Support Techniques; D003944:Diagnostic Techniques, Obstetrical and Gynecological / Q000191:economics*; D005260:Female; D006801:Humans; D006878:Hydroxides; D008795:Metronidazole / Q000627:therapeutic use; D009010:Monte Carlo Method; D017680:Potassium Compounds; D014247:Trichomonas Vaginitis / Q000175:diagnosis / Q000188:drug therapy / Q000191:economics; D014481:United States; D014627:Vaginitis / Q000175:diagnosis* / Q000188:drug therapy / Q000191:economics* / Q000382:microbiology; D016585:Vaginosis, Bacterial / Q000175:diagnosis / Q000188:drug therapy / Q000191:economics
D000890:Anti-Infective Agents; D015342:DNA Probes; D006878:Hydroxides; D017680:Potassium Compounds; D008795:Metronidazole; C029943:potassium hydroxide