Table 1.

Characteristics of Older Adults in Medicare with Multimorbidity whose Predominant Provider of Care is Primary Care vs Other Specialties Before & After Propensity Matching (2011)

	Unmatched			Std Diff*	Matched		Std Diff
	Overall	Primary care	Other Specialty		Primary care	Other Specialty
N	3,924,942	2,648,500	1,276,442
		67.5%	32.5%
Age
Mean (%)	76.9	77.3	76.1	.162	77.3	77.2	.000
65–69	20.1	19.1	22.4	−.081	19.1	18.4	.018
70–74	21.8	21.0	23.4	−.060	21.0	21.0	−.002
75–79	21.3	21.0	21.9	−.022	21.0	21.7	−.018
80–84	19.2	19.7	18.2	.039	19.7	20.2	−.014
85-Up	17.7	19.3	14.2	.139	19.3	18.7	.017
Male (%)	46.3	43.8	51.3	−.150	43.8	43.9	−.001
Race (%)
White	82.0	81.6	82.9	−.034	81.6	81.2	.010
Black	9.3	9.4	8.9	.018	9.4	9.6	−.007
Hispanic	5.5	5.6	5.2	.019	5.6	5.8	−.006
Other	3.3	3.4	3.0	.021	3.4	3.4	−.003
Dual-Eligible (%)	18.5	20.4	14.5	.156	20.4	20.7	− −.008
Median household income	$55,394	$53,866	$58,563	−.180	$53,866	$53,793	.002
Number of chronic conditions (%)
2	56.7	56.7	56.7	−.001	56.7	55.5	.023
3	24.1	24.0	24.4	−.009	24.0	24.4	−.010
4	11.1	11.2	11.1	.003	11.2	11.4	−.008
≥5	8.1	8.2	7.8	.013	8.2	8.6	−.016
Selected Chronic Conditions (%)
Coronary artery disease	18.1	17.2	20.1	−.075	17.2	17.4	−.007
Congestive heart Failure	34.9	34.9	35.0	−.003	34.9	35.3	−.010
Diabetes Mellitus	54.5	56.9	49.3	.153	56.9	57.1	−.004
Dementia	22.3	25.0	16.5	.211	25.0	25.0	.001
HCC score	2.0	1.9	2.1	−.128	1.9	2.0	−.034
Baseline utilization
Number of Visits	15.1	14.5	16.4	−.191	14.5	14.6	−.008
Hospital Discharges (per 1,000)
Total	833.4	842.1	815.5	.023	842.1	862.6	−.012
Medical Discharges	616.8	639.2	570.3	.069	639.2	653.6	−.010
Surgical Discharges	216.6	202.8	245.1	−.085	202.8	209.0	−.009

^*Std diff = Standardized Difference compares the difference in means (or proportions) in the units of the pooled standard deviations between treated and controls and is the recommended measure for comparing balance between propensity-matched groups. A value of greater than 0.1 suggests potentially meaningful lack of balance