Skip to main content

Table 4 Estimated difference in percent medicare visits for MRI exams for physicians Post/Pre Onsite MRI acquisition relative to physicians without onsite MRI, 2007–2009 cohorts

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

∆MRIs as % Visits Model 1 Model 2 Model 3 Model 4
  Coeffi-cient p-value Coeffi-cient p-value Coeffi-cient p-value Coeffi-cient p-value
Onsite MRI −0.330 0.486 −0.139 0.753 −0.237 0.507 −0.468 0.161
MRI Year         
 2007 Reference -- Reference -- Reference -- Reference --
 2008 1.569 0.063 1.570 0.068 0.817 0.125 2.175 0.038
 2009 0.424 0.454 0.567 0.323 0.227 0.533 1.157 0.067
Number of providers         
 1-2 -- -- Reference -- Reference -- Reference --
 3-5 -- -- −1.930 0.088 −1.121 0.398 −1.086 0.448
 6-10 -- -- −2.199 0.037 −2.142 0.076 −1.892 0.095
 >10 -- -- −2.395 0.023 −2.015 0.072 −1.907 0.083
Practice Payer Mix (%)         
 Medicare -- -- -- -- 0.0734 0.006 0.0926 0.010
 Private Insurance -- -- -- -- 0.0660 0.004 0.0644 0.006
 Workers’ Comp -- -- -- -- 0.0289 0.511 0.0442 0.353
 Other -- -- -- -- Reference -- Reference --
Area Characteristics         
 ∆Per cap inc ($1000s) -- -- -- -- -- -- 0.072 0.278
 ∆Pop age 65+ (%) -- -- -- -- -- -- 0.516 0.198
 ∆Unemployment (%) -- -- -- -- -- -- −0.246 0.216
 ∆MDs/1000 Pop -- -- -- -- -- -- −1.215 0.418
F-Statistic (p-value) 1.37 0.266 1.81 0.125 2.80 0.013 2.93 0.007
  1. Sources: see text