NAAT Testing for Gonorrhea and Chlamydia: A Review of Diagnostic Accuracy, Cost-Effectiveness, and Acceptability
At NCCID’s request, the Canadian Agency for Drugs and Technologies in Health (CADTH) conducted a review on the diagnostic accuracy, cost-effectiveness and compliance with testing for gonorrhea and chlamydia. This paper is a companion for the full-length 2009 CADTH Technology Report, “Urine Based Testing for Gonorrhea and Chlamydia: A Review of Diagnostic Accuracy, Cost-Effectiveness, and Compliance.” Here, the Report is condensed to highlight the conclusions and implications for public health practice and policy. Furthermore, we provide additional information on the concept behind nucleic acid amplification tests (NAATs) and discuss other pertinent issues related to the interpretation of the CADTH Technology Report.
NAATs are powerful molecular techniques for the screening and diagnosis of infectious microorganisms.
Three commercially available NAATs are approved in Canada for the screening and diagnosis of chlamydia and gonorrhea.
NAATs are, in most instances, highly sensitive and specific for chlamydia and gonorrhea testing on urine, cervical swab or urethral swab specimens. However, some studies show that factors within urine samples could hamper the performance of NAATs.
Studies that directly measure the compliance with testing for chlamydia and gonorrhea are generally lacking, but several systematic reviews and observational studies report important factors that could enhance compliance.
Cost-effectiveness and cost-savings of NAATs for screening for chlamydia and gonorrhea have been demonstrated in some mathematical modelling studies. However, there is a paucity of cost-effectiveness modelling studies that are based on Canadian data.
No study regarding the stability of urine-based or swab-based specimens during storage or transport could be found.
NAAT technologies can be adopted for other applications in public health.