Table 3.

Effect of calcium supplementation^a by treatment compliance.^b

		Average (Overall)			Second trimester			Third trimester
Compliance	No.	β	% Δc	p-Value	β	%Δc	p-Value	β	%Δc	p-Value
All	557	−0.12	−11%	0.004	−0.15	−14%	0.001	−0.08	−8%	0.107
< 50%	82	0.18	20%	0.115	0.30	35%	0.024	0.09	9%	0.497
≤ 50%	475	−0.17	−15%	< 0.001	−0.22	−20%	< 0.001	−0.11	−10%	0.037
≤ 67%	357	−0.20	−19%	< 0.001	−0.28	−24%	< 0.001	−0.12	−11%	0.054
≤ 75%	241	−0.27	−24%	< 0.001	−0.32	−27%	< 0.001	−0.21	−19%	0.004

^aAdjusted for baseline blood lead level, maternal age, dietary calcium intake at baseline, daily energy intake at baseline, treatment group, and trimester of pregnancy.

^bWe assessed compliance by pill count at each visit and analyzed it as proportion of expected pills used between baseline (first trimester) and end of follow-up (8 months’ gestation).

^cPercent change; log-transformed outcome variable, thus estimate of treatment effect: 1 − e^−β.