Background Culture of Neisseria gonorrhoeae from the urethral and endocervix is currently the recommended method of detecting gonorrhoea (GC) in women in the UK. This necessitates a speculum examination. NAATs are the mainstay of testing for Chlamydia trachomatis (CT) infection and assays exist which can also detect GC. NAATs are more sensitive than culture meaning non-invasive samples can be used. No previous study has compared self-taken VVS analysed by AC2 with urethral and endocervical GC culture, which is considered the gold standard test in the UK. We therefore undertook this comparison in a clinical setting with low GC prevalence and performed a cost-effectiveness analysis.
Methods Participants were recruited within the Centre for Sexual Health at Leeds, UK between March 2009 and January 2010. The women, presenting for a new visit, performed a self-taken VVS and were then examined and urethral and endocervical samples taken for GC culture. Positive AC2 tests were confirmed by the Aptima GC and/or Aptima CT mono-specific platform tests. The cost effectiveness was analysed using incremental cost effectiveness ratios (ICERs). The analysis uses correct detection of GC as the primary endpoint and adopts the perspective of the UK National Health Service. Costs were estimated from a sub-sample of 92 patients in July 2009. The analysis includes costs of clinic time, together with the laboratory costs. Comparisons were made of self-taken VVSs using AC2 vs clinician taken cultures for the whole cohort.
Results 100 of the 3973 participants (2.5%) were infected with GC. The overall sensitivity of GC culture was 82% and self-taken VVS 95%. 35% of the participants were asymptomatic in whom GC culture sensitivity was 79% and self-taken VVS 91%. The cost effectiveness results are presented in Abstract P3-S1.24 table 1.
Conclusions Self-taken VVS analysed by AC2 are cost effective compared to urethral and endocervical GC culture; being more sensitive and less costly. Whilst those presenting with symptoms continue to require a clinician examination use of VVSs in women with no symptoms removes the need for examination. The cost of the time taken in explanation of self taken swabs for this group represents <20% of the cost of a clinician examination. Cost savings also accrue through use of AC2 alone rather than GC culture and CT NAAT.