MRI algorithm for medical necessity for auto accident injured patients.

RATIONALE: Magnetic resonance imaging (MRI) is often used as a diagnostic test to evaluate personal injury. However, it increases the health care cost. Therefore, it is important to study the necessity for using MRI.

OBJECTIVE

To examine the percentages of MRI ordering between orthopaedic surgeon and non-surgeon referring health care providers, and to propose an MRI an algorithm to reduce unnecessary MRI for patients with personal injuries.

METHODS

This is a retrospective study. A total of 2000 patients that received a soft tissue injury and did not require surgery between 1 January 2000 and 31 December 2004, were examined. Among them, 1000 patients came directly to one of the authors, an orthopaedic surgeon, and other 1000 were referred to the same surgeon. The percentages of MRI ordered by the author and the referring health care providers are examined. For referred patients, the orthopaedic author re-examined each patient to determine whether he thought the MRI was necessary. The Chi-square test and McNemar's test are used for comparisons for the percentages, and confidence intervals are reported. The study examines the overall MRI ordering, and MRI ordering separately for body regions.

CONCLUSIONS

We found that there was a great disparity between the percentages of MRI ordering between the orthopaedic surgeon and the non-surgeon referring doctors, the orthopaedic surgeon ordered significantly less MRI (P-values < 0.001). Adopting the proposed algorithm of medical necessity for ordering MRI or considering early referral to an orthopaedic surgeon prior to ordering MRI can significantly reduce the medical cost for these patients.