Table 3.

Multivariable Zero-Inflated β Regression Analysis of Risk Factors for High Schistosoma haematobium Infection Intensity Among Pregnant Women

Factor	Zero-Inflated Negative Binomial Model
	Odds of Egg Negative (n = 4437)		Infection Intensity (n = 4430a)
	Adjusted ORb, c (95% CI)	P	IRR (95% CI)	P
Maternal factors
Parity	0.99 (.85–1.15)	.888	0.95 (.82–1.10)	.483
Years of education	1.06 (.98–1.14)	.166
Age	1.07 (1.03–1.11)	.001
Marital status
Married	1.00		1.00
Not married	1.52 (.55–4.22)	.420	2.91 (1.06–8.04)	.039
Religion
Apostolic	1.00		1.00
Other Christiansd	1.45 (1.04–2.04)	.031	1.41 (.93–2.14)	.104
Other religions	0.97 (.56–1.69)	.914	1.14 (.68–1.91)	.614
Household factors
Household wealth
Lowest quintile	1.00
Second	0.93 (.61–1.41)	.720
Middle	1.36 (.84–2.20)	.207
Fourth	1.16 (.75–1.79)	.498
Highest quintile	1.23 (.70–2.18)	.476
WASH factors
Any latrine
Yes	1.00
No	0.83 (.41–1.69)	.606
Improved latrine
Yes	1.00
No	1.07 (.51–2.22)	.863
Improved drinking water
Yes	1.00
No	0.81 (.61–1.07)	.143
Environmental factors
Minimum temperature			0.79 (.21–2.91)	.722
Study hub
Chirumanzu district
Mvuma	1.00
St Theresa	0.77 (.47–1.25)	.285	0.75 (.39–1.44)	.384
Shurugwi district
Shurugwi	0.48 (.30–.75)	.001	0.45 (.25–.80)	.007
Tongogara	0.73 (.45–1.20)	.217	1.04 (.50–2.21)	.891

Abbreviations: CI, confidence interval; IRR, incidence risk ratio; OR, odds ratio; WASH, water, sanitation, and hygiene.

^aSeven participants had known schistosomiasis status but unknown infection intensity.

^bAdjusted for all other factors included in the multivariable model; variables associated with infection at P < .25 in univariable GEE (Supplementary Table 3) were entered into multivariable models.

^cOdds of being negative for S. haematobium eggs in urine.

^dOther Christians include: Protestants, Pentecostals, Catholics, and other Christian groups.