MSc (Med), Epidemiology and Biostatistics, University of the Witwatersrand / Introduction
This secondary data analysis of a prospective cohort study set out to describe the
association between the use of hormonal contraception and sexually transmitted
infection (STI) acquisition in a cohort of 752 HIV negative women who were followed
up for a year.
Methods
Outcome variables were measured by standard laboratory tests (PCR for Chlamydia
trachomatis (CT) and Neiserria gonorrhoea (NG), culture for Trichomonas vaginalis
(TV) and gram stain with Nugent score for Bacterial Vaginosis (BV). Exposure
variable information was collected by structured interview. Basic descriptive
statistics were applied to describe the characteristics of the cohort, including a
comparison of women who used contraception and those who did not. A time series
analysis including incidence rates for the outcomes (CT, NG, TV and BV), Kaplan
Meier curves for time to event measurement and Cox regression models (univariate
and multivariate), for the estimation of risk were applied.
Results
The analysis found no significant difference between women who use hormonal
contraception and those who did not with respect to baseline demographic
characteristics. Incidence rates per 100 women years to follow up with 95%
confidence intervals were: CT 13 (7 to 17), NG 2 (1 to 4), TV 6 (4 to10), BV 72 (63 to
83). Kaplan Meier curves showed no significant difference in time to event between women who used contraception and those who did not. Adjusted hazard ratios for
women who used contraception was 1.12 (0.69 to1.82) for CT, 0.47 (0.17 to 1.30)
for NG, 1.06 (0.48 to 2.34) for TV and 0.27 (0.05 to 1.52) for BV.
Conclusion
This analysis did not reveal any significant associations between the use of
hormonal contraception and the acquisition of STIs, however the trends in risks
follow those reported in the literature.
Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/8753 |
Date | 21 September 2010 |
Creators | Moyes, Jocelyn Anstie |
Source Sets | South African National ETD Portal |
Language | English |
Detected Language | English |
Type | Thesis |
Format | application/pdf |
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