Table 5.

Control arm: Are usage patterns associated with gestational weight gain?

Usage patternsa		Excessive total GWGb			Excessive GWG rate			GWG
		RRc	95% CI	P value	RR	95% CI	P value	Estimate	95% CI	P value
Stratum 1: normal range BMId and low income (n=86)
	Low usere	1.30	0.64 to 2.64	.47	1.07	0.69 to 1.67	.76	−0.05	−2.88 to 2.77	.97
	Mid or high user	1.56	0.72 to 3.38	.26	1.25	0.79 to 2.00	.34	2.56	−0.10 to 5.22	.06
Stratum 2: normal range BMI and higher income (n=161)
	Low user	0.83	0.40 to 1.75	.63	0.97	0.63 to 1.50	.90	−0.29	−2.24 to 1.66	.77
	Mid or high user	0.94	0.47 to 1.87	.85	1.13	0.75 to 1.72	.55	0.64	−1.36 to 2.64	.53
Stratum 3: overweight or obese BMI and low income (n=82)
	Low user	1.31	0.81 to 2.13	.28	1.35	1.00 to 1.82	.05	2.31	−0.79 to 5.40	.14
	Mid or high user	1.11	0.67 to 1.82	.69	1.03	0.72 to 1.46	.89	1.39	−1.78 to 4.56	.39
Stratum 4: overweight or obese BMI and high income (n=108)
	Low user	1.34	0.90 to 2.00	.15	1.09	0.84 to 1.43	.52	0.54	−2.08 to 3.16	.69
	Mid or high user	1.13	0.75 to 1.70	.56	1.12	0.86 to 1.47	.40	−0.44	−3.19 to 2.30	.75

^aAll models have been adjusted for age, race, parity, and BMI.

^bGWG: gestational weight gain.

^cRR: relative risk.

^dBMI: body mass index.

^eRelative risk of excessive GWG and mean GWG estimates (kg) are relative to subjects who were nonusers (reference group).