Condom effectiveness against non-viral sexually transmitted infections: a prospective study using electronic daily diaries.

OBJECTIVES

To prospectively evaluate the protective value of consistent and correct use of latex condoms against the acquisition of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis.

METHODS

Patients (N=929) attending clinics that treat sexually transmitted infections (STIs) were prospectively followed for up to 6 months. Urine STI nucleic acid amplification testing was performed at baseline, 3 months and 6 months. Participants were instructed to respond to daily prompts from a handheld device by completing a report for each penile-vaginal sexual intercourse event. Generalised estimating equation models examined associations of consistent as well as consistent and correct condom use with STI incidence over 3-month intervals.

RESULTS

Consistent condom use was not significantly associated with STI incidence (Estimated OR (EOR)=0.75; 95% CI (CI) 0.43 to 1.30; p=0.31). However, individuals who used condoms both correctly and consistently were estimated to have 59% lower odds of acquiring an STI (EOR=0.41; 95% CI  0.19 to 0.90; p=.026), compared to those who did not.

CONCLUSIONS

The correct as well as the consistent use of condoms greatly reduces the odds of non-viral STI acquisition.