In-office magnetic resonance imaging (MRI) equipment ownership and MRI volume among medicare patients in orthopedic practices

Table 3 Sample means for physician practice sample, by on-site MRI status

	All	MRI	No MRI
	[n = 433]	[n = 252]	[n = 181]
MRI Volume ^a (% Medicare Visits)
Pre-MRI year	1.151	1.460	0.595
Post-MRI year	1.312	1.530	0.919
∆(Post-Pre)	0.161	0.071	0.324
Ortho-MRI Volume ^b (% Medicare Visits)
Pre-MRI year	1.066	1.391	0.482
Post-MRI year	1.239	1.478	0.809
∆(Post-Pre)	0.173	0.087	0.327
MRI Year (%)
2006	38.55	44.72	27.43
2007	26.54	31.21	18.14
2008	34.91	24.08	54.42
Number of providers (%)
1-2	2.37	1.47	3.98
3-5	6.64	5.90	7.96
6-10	26.86	12.53	52.65
>10	64.14	80.10	35.40
Practice Payer Mix (%)
Medicare	27.07	26.13	28.77
Private Insurance	46.90	47.83	45.22
Workers’ Comp	12.30	12.10	12.64
Other	13.74	13.94	13.38
Area Characteristics (Post-Pre)
∆Per capita income ($1000s)	1.211	1.916	−0.058
∆Pop age 65+ (%)	0.449	0.467	0.417
∆Unemployment (%)	2.860	2.461	3.578
∆MDs/1000 Population	−0.0018	−0.0045	0.0032

Sources: Medicare Claims Data; AAOS Survey Data, 2012; Area Resource File (see text)
^aHCPCS codes 71552, 73218, 73718, 74183, 77059, 70543, 70551, 70553, 72141, 72146, 72148, 72156, 72157, 72158, 72195, 72197, 73220, 73221, 73222, 73223, 73720, 73721, 73722, 73723, 70336, 70540, 70542, 70552, 71550, 71551, 72142, 72147, 72149, 72196, 73219, 73719, 74181, 74182, or 77084
^bHCPCS codes 72141, 72146, 72148, 72156, 72157, 72158, 72195, 72197, 73220, 73221, 73222, 73223, 73720, 73721, 73722, or 73723

ISSN: 2191-1991