We aimed to evaluate the cost-effectiveness of screening for sexually transmitted infections (STI), Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis in patients with suspected urinary tract infection (UTI) but negative urine cultures, using a pooled sampling method. A cohort of 200 patients was analyzed. A decision tree model based on cost-effectiveness was used to evaluate the following five diagnostic strategies: (A) no screening
(B) screening only men
(C) screening only women
(D) screening men and women with high leukocyte counts (>
70cells/µL)
(E) screening all men and women. The pooling method reduced reagent testing costs by 75 %. The most cost-effective strategy was screening men and women with high leukocyte counts, yielding an incremental cost-effectiveness ratio of 489.05euros. STI screening using pooled midstream urine samples in patients with suspected UTI and negative urine cultures is cost-effective, particularly when targeting individuals with high leukocyte counts. This approach optimizes resource use and improves early STI detection.