Table 3. Bacterial consistency determined by Bray-Curtis dissimilarity scores between consecutive pairs of specimens.
| Characteristic | Mean difference in dissimilarity scores within each characteristic (adjusted for all covariates) | 95% CI | p valuea | |
|---|---|---|---|---|
| Caucasian ethnicityb | -0.04 | -0.17, 0.08 | 0.492 | |
| Continuous OCP-usec | -0.12 | -0.24, 0.01 | 0.063 | |
| Sexual activity categoryd | ||||
| No sex during paired intervals | ref | |||
| Non-coital/initiate non-coital | -0.05 | -0.19, 0.09 | 0.492 | |
| Penile-vaginal sex/initiate penile-vaginal sex | 0.06 | -0.06, 0.19 | 0.307 | |
| Dominant bacteria in reference specimene | ||||
| Other heterogeneous non-lactobacilli | ref | |||
| L. crispatus | -0.36 | -0.53, -0.19 | <0.001 | |
| L. iners | -0.38 | -0.53, -0.23 | <0.001 | |
| L. gasseri or L. jensenii | -0.25 | -0.48, -0.02 | 0.030 | |
| G. vaginalis | -0.15 | -0.38, -0.02 | 0.197 | |
Bray-Curtis dissimilarity scores were calculated between paired consecutive longitudinal samples over multiple time points from each participant, where the first sample in each consecutive pair is the reference specimen. Scores were given a value from 0–1; samples with a score of 0 being having all species/genera in common and those scoring 1 with no bacterial species/genera in common.
aregression analysis using a random-effects model adjusting for all listed characteristics and clustering by participant to account for multiple specimens (52 clusters)
bcompared to the combined ethnicity groups Central or South-East Asian and Indian or Sri-Lankan
ccompared to non-oral contraceptive pill (OCP) users
dsexual activity categories for this analysis were specified as non-coital experience or progression from no activity to non-coital sex or unprotected penile-vaginal sex or initiation of unprotected penile-vaginal sex throughout the follow up period and both were compared to women who had no sex during the paired intervals
ecompared to first specimen of each consecutive pair (reference specimen) dominated by other heterogeneous non-lactobacilli (predominately A. vaginae and Prevotella spp.)