The Prevalence of Defensive Orthopaedic Imaging: A Prospective Practice Audit in Pennsylvania

Abstract

Defensive medicine has been identified as an area of wasteful health-care spending. Estimates of its prevalence and its contribution to the cost of defensive practices have varied widely. To date, there has been no prospective evaluation of the use of defensive medicine for musculoskeletal conditions. Members of the Pennsylvania Orthopaedic Society were queried by means of an anonymous, prospective audit of consecutive imaging decisions in their clinical practice. For each image order, respondents recorded the modality, the body region imaged, and whether the imaging was "required for clinical care" or "ordered for defensive reasons." We evaluated the proportion of images that were ordered defensively, identified demographic differences with use of the chi-square test of independence, and calculated the contribution of defensive imaging to the total cost with use of 2009 Medicare reimbursement rates. Seventy-two orthopaedists recorded 2068 imaging decisions made during the day that their practice was audited. Defensive imaging represented 19.1% (396) of the orders and 34.7% ($113,675) of the total cost ($327,414). Magnetic resonance imaging (MRI) represented 48.7% of the defensive orders, and 38.5% (193) of the 501 MRIs were ordered for defensive reasons. The proportion of defensive imaging ordered by orthopaedists who had been sued for medical malpractice within the previous five years was significantly greater than the proportion ordered by those who had not been sued during the same time frame (24.6% compared with 15.1%, p < 0.001). The proportion of defensive imaging ordered by orthopaedists who had been in practice for more than fifteen years was significantly greater than the proportion ordered by those who had less experience (20.8% compared with 17.1%, p = 0.03). In a prospective practice audit of orthopaedists, defensive imaging was found to be both common and costly. Recent litigation experiences and longer duration of orthopaedic practice were independent predictors of an increased use of defensive practices in ordering imaging studies. This real-time audit showed that a large proportion of MRI studies were ordered for primarily defensive medicine reasons.