Analyzing Adherence to Prenatal Supplement: Does Pill Count Measure Up?

Table 2

Results of the primary logistic regression model predicting adherence as determined by the novel serum 25(OH)D definition.

Subject characteristic	𝑁	Odd ratio	95% confidence interval	𝑃-value
Mean percent adherence (as measured by pill count)	161	1.2∗	(0.9, 1.6)	.29
Maternal age	161	1.0†	(1.0, 1.1)	.45
Race
Black	32	1.8	(0.6, 5.0)	.20
Latina	76	1.0	(0.4, 2.3)	.41
White	53	Referent	—
Body mass index	161	1.0‡	(1.0, 1.1)	.22
Dose
2000 IU	85	0.5	(0.2, 0.9)	.02
4000 IU	76	Referent	—
Season at enrollment
Spring	53	0.7	(0.3, 1.8)	.30
Summer	40	0.7	(0.2, 1.8)	.24
Fall	34	1.7	(0.6, 4.9)	.08
Winter	34	Referent	—

∗Mean percent adherence was treated as a continuous measure in the model; however, this variable was coded such that the odds ratio reflects the increase in odds associated with a 10-percent increase in mean percent adherence.
†Maternal age at baseline was treated as a continuous measure in the model; however, this variable was coded such that the odds ratio reflects the increase in odds associated with a 1-year increase in age.
‡Body mass index was treated as a continuous measure in the model; however, this variable was coded such that the odds ratio reflects the increase in odds associated with a 1-unit increase in body mass index.