Quantifying the defensive medicine contribution to primary care costs

Defensive medicine represents one cause of economic losses in healthcare. Studies that measured its cost have produced conflicting results.

To directly measure the proportion of primary care costs attributable to defensive medicine.

Six-week prospective study of primary care physicians from four outpatient practices. On 3 distinct days, participants were asked to rate each order placed the day before on the extent to which it represented defensive medicine, using a 5-point scale from 0 (not at all defensive) to 4 (entirely defensive).

This study calculated the order defensiveness score for each order (the defensiveness/4) and the physician defensive score (the mean of all orders defensiveness scores). Each order was assigned a weighted cost by multiplying the total cost of that order (based on Medicare reimbursement rates) by the order defensiveness score. The proportion of total cost attributable to defensive medicine was calculated by dividing the weighted cost of defensive orders by the total cost of all orders.

Of 50 eligible physicians, 23 agreed to participate; 21 returned the surveys and rated 1234 individual orders on 347 patients. Physicians wrote an average of 3.6 ± 1.0 orders/visit with an associated total cost of $72.60 ± 18.5 per order. Across physicians, the median physician defensive score was 0.018 (IQR = [0.008, 0.049]) and the proportion of costs attributable to defensive medicine was 3.1% (IQR = [0.5%, 7.2%]). Physicians with defensive scores above vs below the median had a similar number of orders and total costs per visit. Physicians were more likely to place defensive orders if trained in community hospitals vs academic centers (OR = 4.29; 95% CI = 1.55-11.86; p = 0.01).

This study describes a new method to directly quantify the cost of defensive medicine. Defensive medicine appears to have minimal impact on primary care costs.