Table 3.

Number of covariates by data source, along with mean standardized differences and percentage with standardized difference greater than 0.05 before and after propensity score(PS) adjustment.

Data source	Covariates	Before PS		After PS
		Mean	$>0.05(\%)$	Mean	$>0.05(\%)$
P-Plus	6611	0.23	6.1	0.04	0
Optum CEDM	6890	0.2	8.2	0.05	0.015
Truven CCAE	5605	0.16	4.3	0.05	0
Truven MDCR	4726	0.2	8.8	0.06	0.11
NHIS NSC	3138	0.36	26	0.13	21
Truven MDCD	1873	0.32	53	0.21	49
Cerner UT	721	0.46	72	0.13	20
Columbia	379	0.73	84	0.44	66
Stanford	288	0.45	81	0.44	81