Table 6.

Multivariable binary logistic regression coefficients and risk score for variables retained in the final reduced model for prediction of preterm birth among pregnant women attending ANC, 2020–2022

Predictor Variable	category	Multivariable Analysis		Reduced model		Risk Score
		β (95%CI)	p-value	β (95%CI)	p-value
Age	< 20	1.458 (0.124–2.791)	0.032	1.628(0.363, 2.892)	0.012	2
	20–24	1		1
	25–29	0.077 (-0.86-1.014)	0.872	0.114(-0.792, 1.02)	0.805
	30–34	-0.009(-0.754-0.736)	0.98	-0.011(-0.74,0.724)	0.977
	≥ 35	− 0.715 (-1.639-0.209)	0.129	-0.642(-1.55,0.266)	0.166
Residence	Urban	1
	Rural	0.349 (-0.347-1.044)	0.326	NA
MUAC	≥ 24 cm	1		1
	< 24 cm	0.616 (-0.122-1.353)	0.102	0.523(-0.096,1.142)	0.098
Weight of Mother	≥ 50 kg	1
	< 50 kg	-0.33(-1.201.542)	0.458	NA
Gravidity	Primigravida	1
	Multigravida	-0.337(-1.689-1.015)	0.625	NA
Parity	Nullpara	1		1
	Primipara	0.782 (-0.497-2.061)	0.231	0.565(-0.252,1.382)	0.175
	Multipara	1.359 (0.086–2.632)	0.036	1.138(0.324,1.953)	0.006	2
Timing of ANC	Early initiation	1		1
	Late initiation	0.821 (0.062–1.58)	0.034	0.782(0.042,1.522)	0.038	1
Pregnancy status	Unplanned	1.194 (0.622–1.766)	0.000	1.188(0.626,1.751)	0.001	2
	Planned	1		1
Hemoglobin	≥ 11 g/dl	1		1
	< 11 g/dl	4.227 (3.268–5.185)	0.000	4.198(3.254,5.141)	0.001	5
Comorbidity	No	1
	Yes	0.273 (-1.548-2.094)	0.769	NA
Recent pregnancy complication	No	1		1
	Yes	3.59 (2.994–4.186)	0.000	3.613(3.019,4.207)	0.001	5
Constant		-5.627(-6.702-4.552)		-5.682(-6.71-,4.64)	17 total risk score

MUAC Middle Upper Arc Circumference, ANC Antenatal care, CI Confidence Interval