A decision-tree model was designed to assess a hypothetical cohort of 10,000 women per year who requested Chlamydia trachomatis screening. The time horizon was 10 years. The authors reported that the perspective was that of the public health care system.
The clinical and effectiveness data were from a number of sources, including data collected from July 2004 to June 2010 as part of the evaluation of the self-testing website, and published studies. The relative screening rates were from a study comparing home-based screening to clinic-based screening. A literature search in PubMed was used to determine the sensitivity and specificity of the vaginal and endocervical Aptima Combo 2 (AC2) tests. The key terms of the search and the inclusion criteria were reported.
Monetary benefit and utility valuations:
Measure of benefit:
The measure of benefit was the number of cases of pelvic inflammatory disease (PID) that were prevented.
The direct costs were those of website maintenance and personnel, screening kits, tests, clinician visits, consumables (gloves, drapes, speculum, etc.), medication, in-patient and out-patient treatment for PID, and treatment for infertility, ectopic pregnancy, and pain. The resource use and costs were from the evaluation of the self-testing intervention and from published studies. The price year was 2010 and future costs were discounted at an annual rate of 3%. All costs were reported in US dollars ($).
Analysis of uncertainty:
One- and two-way sensitivity analyses were undertaken by varying all the parameters over defined ranges.