Background Asymptomatic non-gonococcal non-chlamydial urethritis (NCNGU) is common and can only be diagnosed by urethral smear microscopy. UK guidelines no longer recommend urethral smear microscopy in asymptomatic men, leaving men with this condition and their sexual partners untreated. The clinical and economic significance of this is unclear. We do not know if the costs of microscopy screening for asymptomatic NCNGU outweigh any future health benefits. We performed a model based economic evaluation to compare a screening strategy which includes microscopy to one which omits microscopy in asymptomatic men.

Methods The economic model was from the perspective of the UK health service and so only direct medical costs and outcomes are included. A hypothetical cohort of asymptomatic men who present at sexual health clinics, or at primary care is assumed to have Chlamydia trachomatis, Neisseria gonorrhoeae or NCNGU. In the economic model, untreated infections were taken into account for patients and their partners (pelvic inflammatory disease and tubal factor infertility in female partners). Probabilities and frequencies of these health events were informed by the outputs of a mathematical transmission model which used data from literature and national databases. A bottom-up costing estimated the cost for microscopy screening, while other cost inputs were sourced from published literature and online reference manuals for the economic evaluation. Appropriate sensitivity analyses were conducted to test the baseline results.

Results Currently, there are no robust quality-adjusted-life-year (QALY) data to value STI outcomes. Consequently, results will be presented as cost per major outcome avoided and cost per infection avoided, where major outcome averted refers to PID, infertility and tubal factor infertility. Incremental cost-effective ratios will be interpreted based on accepted precedents.

Conclusions The UK's current financial restraint has increased the importance of allocating resources based on need and value-for-money. This in turn, requires the UK health service to eliminate ineffective and inefficient services to create additional source of funding. Results from this study will indicate whether microscopy testing for asymptomatic men is good use of public money and whether funding for the service should be maintained.