TABLE 1.

Simulated HR When Gestational Weight Gain Is Measured at Intermittent Visits

True HR	Model	Predictors	Estimated HR	Standard Error	95% CI Coverage (%)
1.3	Survival	Intermittent visitsa	1.30	0.02	94
	Binomial	1 st trimesterb	1.29	0.08	95
		2nd trimesterc	1.29	0.05	94
		3rd trimesterd	1.30	0.04	95
1.1	Survival	Intermittent visits	1.10	0.01	95
	Binomial	1 st trimester	1.10	0.07	95
		2nd trimester	1.10	0.04	95
		3rd trimester	1.10	0.03	95
1.0	Survival	Intermittent visits	1.00	0.01	95
	Binomial	1 st trimester	1.00	0.06	95
		2nd trimester	1.00	0.04	95
		3rd trimester	1.00	0.03	95
0.9	Survival	Intermittent visits	0.90	0.01	95
	Binomial	1 st trimester	0.90	0.05	95
		2nd trimester	0.90	0.04	95
		3rd trimester	0.90	0.03	95
0.7	Survival	Intermittent visits	0.70	0.01	94
	Binomial	1 st trimester	0.73	0.05	91
		2nd trimester	0.72	0.04	90
		3rd trimester	0.71	0.03	93

^aFour visits at 1st trimester, 2nd trimester, 3rd trimester, and delivery. Weight gain values are linearly interpolated between visits.

^bBetween 10 and 12 weeks.

^cBetween 18 and 23 weeks.

^dBetween 25 and 36 weeks.

HR indicates hazard ratio; 95% CI, 95% confidence interval.