TABLE 3.

Regression models by risk groups

Risk group characteristic(s)m/naRegression modelAUCCI for AUC
Previous PTD but no     vaginal bleeding9/28logit (p) = 20.86 − 1.33 × pH −2.6 × total anaerobic count + 0.58 × maximum H2O2-positive Lactobacillus sp. count + 0.70 × maximum Peptostreptococcus sp. count0.910.79-1.00
Previous PTD with or     without vaginal     bleeding11/32logit (p) = 27.35 − 3.27 × pH + 1.92 × bothb − 2.22 × total anaerobic bacterium count + 0.64 × maximum H2O2-positive Lactobacillus sp. count + 0.22 × maximum Peptostreptococcus sp. count + 0.21 × Gardnerella sp. count − 0.32 × maximum Staphylococcus sp. count0.820.65-0.98
Bleeding or no obvious     risks; H2O2-positive     lactobacilli present15/139logit (p) = 2.05 − 0.75 × total anaerobic bacterium count − 0.48 × total aerobic bacterium count + 0.29 × maximum H2O2-positive Lactobacillus sp. count + 0.21 × maximum Staphylococcus sp. count + 0.27 × maximum Corynebacterium sp. count + 0.34 × maximum Gardnerella sp. count0.740.62-0.87
Bleeding or no obvious     risks; H2O2-positive     lactobacilli absent2/35logit (p) = −81.14 − 0.45 × total aerobic bacterium count + 8.72 × maximum Lactobacillus sp. count + 0.74 × maximum Streptococcus sp. count0.940.81-1.00
  • a m, number of PTD cases; n, number of subjects with all covariates.

  • b both, indicator variable for having both vaginal bleeding and previous PTD.