TABLE 3.

Results of the Decomposition of the Cost Difference Between Medicare Beneficiaries Attributed to Primary Care Physicians and Those Attributed to Nurse Practitioners by Primary Care Service Category and Contributing Factors for Low-risk and High-risk Strata

	Low-risk Stratum (N=140,385)					High-risk Stratum (N=140,379)
Primary Care Service Categories	Payment Difference ($)	Service Mix Difference ($)	Service Volume Difference ($)	Sum All Differences ($)	% Contribution of Service Category	Payment Difference ($)	Service Mix Difference ($)	Service Volume Difference ($)	Sum All Differences ($)	% Contribution of Service Category
DME	1.12	0.57	0.70	0.15	0	0.58	1.22	0.30	2.10	0
Standard imaging/echo/ultrasound	3.22	2.94	18.66	24.81	7	12.70	47.18	23.04	57.52	4
Advance imaging	3.07	4.90	8.30	16.27	4	19.44	49.39	12.01	80.84	6
Office visits	22.73	50.20	52.47	125.41	34	38.72	255.98	32.04	326.74	25
Home visit	0.16	11.76	2.81	8.78	−2	0.50	49.41	4.62	44.28	−3
Specialist visits	8.33	2.39	16.98	22.91	6	35.07	63.70	14.73	13.89	−1
Hospital/emergency department/nursing home visit	19.82	67.74	28.98	18.94	−5	443.85	325.03	161.02	279.84	22
Other services	0.80	0.10	25.56	26.25	7	136.32	81.18	84.29	29.16	2
Anesthesia	0.95	4.93	5.17	11.06	3	6.51	39.50	7.17	53.19	4
Major procedures	4.05	26.20	26.71	56.96	15	14.57	164.22	27.47	206.26	16
Minor/ambulatory procedures	6.60	25.33	34.38	66.31	18	46.40	67.13	23.60	137.13	11
Endoscopy/oncology/dialyses	2.17	8.34	9.67	20.18	5	22.49	73.70	17.52	113.72	9
Ordinary lab tests	4.09	6.20	24.73	14.44	4	61.95	66.83	30.78	25.90	2
Other tests	1.05	8.78	5.51	13.23	4	7.36	41.61	6.57	55.55	4
Other	0.64	3.96	1.42	1.89	−1	11.67	27.80	3.56	12.57	−1
Total	66.28	40.04	262.04	368.36	100	560.08	288.36	448.75	1297.20	100

DME indicates durable medical equipment; PCMD, primary care physicians; PCNP, primary care nurse practitioners.