Table 1.

The L₁ measure of imbalance before and after CEM.

Variables	Before Matching		After Matching
	L1	Mean	L1	Mean
Age	0.099	0.185	9.30 × 10−16	6.00 × 10−15
Gender	0.051	−0.050	6.70 × 10−16	2.40 × 10−15
Quintiles	0.16	−0.452	1.10 × 10−15	5.80 × 10−15
SAH	0.015	0.028	4.90 × 10−16	1.60 × 10−15
Multivariate L1	0.252		9.07 × 10−16