Table 5.

Comparison of Utilization Variables During Baseline (2005) and Program (2008) Year Following Application of Coarsened Exact Matching (CEM)^*

	Baseline Year†		Program Year
Explanatory Variables	Treatment (n=7833)	Comparison (n=7221)	Treatment (n=7833)	Comparison (n=7221)	% Δ‡
Inpatient Stays	0.50	0.50	0.43	0.51	2.0% CP ||−14.0% TX
	(0.0119)	(0.0094)	(0.0107)	(0.0029)
Emergency Department Visits	0.20	0.21	0.21	0.22	4.8% CP || 5.0% TX
	(0.0048)	(0.0022)	(0.0042)	(0.0012)
Outpatient Visits	12.71	13.24	13.08	13.83	4.5% CP || 2.9% TX
	(0.0781)	(0.0362)	(0.0819)	(0.0239)
Physician Visits	19.71	15.99	22.08	17.36	8.6% CP || 12.0% TX
	(0.0965)	(0.0438)	(0.1047)	(0.0385)

^*Results based on CEM stratification {DURATION_SINCE_CHRONIC_DISEASE_INDICATION_DUMMY, AGE40_DUMMY, GENDER, IP_DUMMY, ED99_DUMMY, PLAN_STATE_DUMMY, PLAN_TYPE}; all values based on the average of 250 simple random samples taken with replacement, with the treatment group sampled (simple random with replacement) at a rate equal to the original comparison group (analyzed comparison group sampled up to 1.5 times the original size). Members were between the ages of 18 and 64.9 years, evidenced to have a chronic condition of coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and/or diabetes (based on administrative claims data), and excluded if medical costs in baseline or program year exceeded the 99^th percentile, or if their change in costs over these 2 periods exceeded the 99^th percentile. Standard deviation in parentheses.

^†Results are based on application of CEM-derived weights.

^‡Independent, relative percent difference in postmatch values (by Explanatory Variable) for comparison (denoted CP) and treatment (denoted TX) group members by year. As an example, for the explanatory variable Inpatient Stays, the delta is computed as: (0.43−0.50)/0.50=−14.0%.