Table 3.

Multivariable Correlates of Preterm Birth

Variables in the Model	Adjusted PR (95% CI)	P Value
Model 1 (n = 1234)
Age ≤ 21 y	1.33 (1.09–1.62)	.005
Education ≤ 8 y, primary school	1.22 (.98–1.52)	.07
Any STIa	1.31 (1.04–1.66)	.02
Abnormal vaginal discharge	1.10 (.87–1.39)	.5
Cervical inflammation	1.17 (.91–1.50)	.2
Model 2 (n = 1234)
Age ≤ 21 y	1.31 (1.07–1.60)	.008
Education ≤ 8 y, primary school	1.24 (1.00–1.54)	.047
Any STIb	1.49 (1.13–1.97)	.005
Abnormal vaginal discharge	1.12 (.89–1.42)	.320
Cervical inflammation	1.20 (.93–1.54)	.149
Model 3 (n = 1230)c
Age ≤ 21 y	1.35 (1.11–1.65)	.003
Education ≤ 8 y, primary school	1.29 (1.04–1.60)	.02
Chlamydia	1.42 (1.04–1.95)	.03
HIV	2.32 (1.65–3.26)	<.001
Abnormal vaginal discharge	1.06 (.85–1.34)	.6
Cervical inflammation	1.23 (.96–1.57)	.1

Abbreviations: CI, confidence interval; HIV, human immunodeficiency virus; PR, prevalence ratio.

^aAny STI includes trichomonas, chlamydia, syphilis, gonorrhea, and HIV.

^bAny STI includes chlamydia, syphilis, gonorrhea, and HIV.

^cModel with chlamydia, gonorrhea, and HIV would not converge so only chlamydia and HIV are included.