Systematic review of the clinical effectiveness and cost-effectiveness of rapid point-of-care tests for the detection of genital chlamydia infection in women and men.

OBJECTIVE: To assess whether or not the Chlamydia Rapid Test (CRT) could improve detection of genital chlamydia, and whether it is more effective than current practice using nucleic acid amplification tests (NAATs), in terms of the number of cases of chlamydia that are detected and treated and the proportion of partners identified and treated. DATA SOURCES: Eleven electronic bibliographic databases (including MEDLINE and EMBASE) were searched until November 2008, as well as relevant websites. REVIEW
METHODS: Studies of sexually active adolescent and adult women and men suspected of having or being tested for genital chlamydia infection were considered. The tests considered were the CRT and other comparator point-of-care tests identified, using a NAAT as a reference standard. Summary sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratios for each model were reported as a median and a 95% confidence interval (CI). Effectiveness was measured in terms of the absolute numbers of true-positives, false-positives, false-negatives (and other positive cases missed) and true-negatives detected. Costs were considered from the health service's perspective. Incremental cost-effectiveness ratios were used to examine the relative cost-effectiveness, and values of the major parameters of the models were varied in a sensitivity analysis.
RESULTS: Thirteen studies enrolling 8817 participants were included in the analysis. In the pooled estimates for the CRT, sensitivity (95% CI) was 80% (73% to 85%) for vaginal swab specimens and 77% (59% to 89%) for first void urine (FVU) specimens. Specificity was 99% (99% to 100%) for vaginal swab specimens and 99% (98% to 99%) for FVU specimens. In the pooled estimates for a comparator point-of-care test (Clearview Chlamydia), sensitivity (95% CI) was 52% (39% to 65%) for vaginal, cervical and urethral swab specimens combined, and 64% (47% to 77%) for cervical specimens alone. Specificity was 97% (94% to 100%) for vaginal, cervical and urethral swab specimens combined, and 97% (88% to 99%) for cervical specimens alone. The results of the economic evaluation showed that for a hypothetical cohort of 1000 people, using the current practice of polymerase chain reaction testing would result in 12.63 people who were offered testing being correctly treated and having their sexual partners contacted, at a cost of 7070 pounds (for the whole cohort). For the CRT, the number being correctly treated would be 10.98, at a cost of 7180 pounds. For the Clearview Chlamydia test, the number correctly treated would be 7.14, at a cost of 7170 pounds. Both point-of-care tests were therefore more costly and less effective than current practice.
CONCLUSIONS: The limited evidence available suggests that NAATs are still the most accurate and cost-effective method for diagnosing chlamydia infection. There may be circumstances in which point-of-care tests could be provided in addition to existing NAAT services, but there is currently little evidence on point-of-care methods in such settings. Robust evidence of the diagnostic accuracy of point-of-care tests for different types of samples is also still required, as are studies evaluating clinical effectiveness outcomes for these tests in comparison with NAATs.