Table 4.

Intervention 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=179)
	Super usere	0.74	0.20 to 2.74	.65	0.53	0.21 to 1.34	.18	−0.69	−3.80 to 2.41	.66
	Medium user	1.51	0.67 to 3.41	.32	1.10	0.72 to 1.70	.65	2.27	−0.89 to 5.43	.16
	Consistent tracker	1.61	0.89 to 2.91	.11	1.24	0.86 to 1.77	.25	1.79	−0.45 to 4.02	.12
	Inconsistent tracker	1.92	1.18 to 3.14	.009	1.25	0.95 to 1.64	.12	2.48	0.63 to 4.33	.009
Stratum 2: normal range BMI and higher income (n=319)
	Super user	0.91	0.50 to 1.68	.77	0.85	0.59 to 1.22	.38	−1.22	−2.82 to 0.39	.14
	Medium user	1.04	0.52 to 2.07	.91	1.12	0.77 to 1.61	.56	0.10	−1.67 to 1.88	.91
	Consistent tracker	0.63	0.34 to 1.16	.14	0.67	0.46 to 0.98	.04	−1.22	−2.91 to 0.46	.15
	Inconsistent tracker	1.33	0.79 to 2.25	.29	1.05	0.77 to 1.44	.75	0.47	−1.12 to 2.06	.57
Stratum 3: overweight or obese BMI and low income (n=172)
	Super user	1.34	0.92 to 1.95	.13	1.25	0.98 to 1.60	.07	0.55	−2.84 to 3.93	.75
	Medium user	0.96	0.56 to 1.64	.87	0.95	0.62 to 1.45	.81	−0.58	−4.51 to 3.34	.77
	Consistent tracker	1.24	0.81 to 1.89	.32	1.11	0.80 to 1.54	.52	1.10	−2.30 to 4.49	.53
	Inconsistent tracker	1.02	0.70 to 1.50	.92	1.10	0.86 to 1.42	.45	0.44	−2.06 to 2.93	.73
Stratum 4: overweight or obese BMI and high income (n=228)
	Super user	0.96	0.72 to 1.30	.80	1.02	0.84 to 1.24	.83	−1.03	−3.59 to 1.53	.43
	Medium user	1.13	0.85 to 1.51	.41	1.06	0.85 to 1.31	.60	−0.01	−2.84 to 2.82	.99
	Consistent tracker	0.96	0.72 to 1.27	.76	1.01	0.83 to 1.23	.93	−2.78	−5.16 to −0.39	.02
	Inconsistent tracker	1.17	0.92 to 1.48	.21	1.13	0.95 to 1.34	.16	0.35	−1.94 to 2.64	.77

^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).