Multiple imputation of missing covariates with non-linear effects and interactions: an evaluation of statistical methods

Table 5 Analysis of vitamin-C data

	Complete		FCS		FCS		JAV
	Cases		with Passive		with PMM
	Est	SE	Est	SE	Est	SE	Est	SE
intercept	0.990	0.201	0.570	0.177	0.903	0.181	1.030	0.163
log diet C	1.141	0.090	1.322	0.079	1.163	0.081	1.106	0.075
log diet C sqrd	-0.090	0.010	-0.113	0.009	-0.094	0.009	-0.088	0.008
sex	0.169	0.008	0.173	0.007	0.172	0.007	0.172	0.007
weight (per 10 Kg)	-0.042	0.003	-0.041	0.003	-0.040	0.003	-0.041	0.003
age (per 10 yrs)	-0.052	0.004	-0.043	0.003	-0.043	0.003	-0.043	0.003
former smoker	0.212	0.015	0.213	0.012	0.213	0.012	0.212	0.012
never smoker	0.216	0.014	0.218	0.012	0.218	0.012	0.219	0.012

Table 5 Point estimates and SEs from complete-case analysis and three MI methods (full conditional specification with and without predictive mean matching, and JAV) for the regression of log plasma vitamin C on log dietary vitamin C ('log diet C'), its square ('log diet C sqrd') and a set of confounders

ISSN: 1471-2288