Table 4.

Impact of smoking status (current smoking, yes/no) on risk of miscarriage or stillbirth among Women's Interagency HIV Study participants, 1994–2014, by HIV status.

	HIV-negative		HIV-positive
Analysis 2: by HIV status	Risk difference (%)	95% confidence limits	Risk difference (%)	95% confidence limits
Crude	15.0	4.9 to 25.1	30.0	21.9 to 38.2
Adjusteda	9.7	0.0 to 19.4	19.2	10.9 to 27.5
Sensitivity analysesb
Adjusted, reduced modelb	8.8	−0.9 to 18.5	21.5	13.3 to 29.8
2.1 Subjects with smoking history	14.2	3.0 to 25.4	24.0	14.1 to 33.9
2.2 Subjects with smoking history and control for previous pregnancy loss	13.0	2.6 to 23.4	23.9	14.0 to 33.7
2.3 First pregnancy	7.3	−7.7 to 22.3	23.5	9.7 to 37.2
2.4 Pregnancies on or after …
1 January 1998	4.2	−6.4 to 14.8	19.7	9.9 to 29.5
1 January 2002	5.5	−6.4 to 17.4	23.7	12.6 to 34.8
2.5 Controlling for bacterial vaginosis	8.0	−1.5 to 17.5	19.2	11.0 to 27.3
2.6 By ART usec
Current ART			20.4	10.4 to 30.5
No current ART			17.5	1.9 to 33.1
2.7 By HAART usec
Current HAART			24.0	13.0 to 35.1
No current HAART			13.4	0.4 to 26.5
2.8 By viral suppression statusd
Suppressed			22.5	11.1 to 33.9
Not suppressed			13.4	0.6 to 26.3

All models account for repeated outcomes within women.

^aFully adjusted models controlled for HIV status (including an interaction term with main exposure), age, socioeconomic status (employment, race, income), BMI, depression, recent use of intravenous drugs, marijuana, and alcohol. Modeling details given in text.

^bSensitivity analyses relied on a reduced model for convergence. The main reduced adjusted model controlled for HIV status (including an interaction term with main exposure), depression, recent use of marijuana and alcohol.

^cThis model did not control for viral load or CD4⁺ cell count, which are affected by ART/HAART use in the last six months.

^dModel also controlled for use of HAART. Suppression was defined as a viral load <1000 copies/ml.