Table 1. Descriptive Summary of Outcome and Predictor Variables, Stratified by Provider Type

Variable	Mean	SD	Min	Max	P^*
UPC (%)^{^†}
All providers	62.92	11.55	37.30	87.40
Physician	60.97	9.84	37.29	78.64	.033
Mid-level	67.78	14.16	41.93	87.41
Clinic frequency (monthly half-day clinic sessions held)
All providers	16.83	7.27	4.92	31.30
Physician	13.63	5.04	4.92	24.42	.000
Mid-level	24.85	5.63	15.06	31.30
Panel size (count of patients assigned to provider)
All providers	577.4	315.8	65	1377
Physician	540.5	274.3	92	1288	.144
Mid-level	669.7	395.4	65	1377
Patient load (ratio of panel size to half-day clinic frequency)
All providers	38.21	19.96	2.40	93.67
Physician	41.32	18.80	5.90	93.70	.049
Mid-level	30.41	21.22	2.41	72.55
Attendance ratio^{^‡}
All providers	1.01	0.26	0.56	2.15
Physician	1.04	0.30	0.56	2.14	.140
Mid-level	0.93	0.13	0.68	1.29
Duration in practice (years)
All providers	6.35	6.38	0.42	24.92
Physician	7.19	6.85	0.67	24.92	.099
Mid-level	4.26	4.50	0.42	16.75