COMPARING THE USE OF DIAGNOSTIC-TESTS IN CANADIAN AND US HOSPITALS

Although Americans pay much more for a day in the hospital than Canadi ans, we know little about whether inpatient physician practice pattern s might explain some of this difference. The authors compared the util ization of all diagnostic imaging (plain radiographs, computed tomogra phy (CT) and magnetic resonance imaging (MRI) scanning, ultrasound, nu clear medicine and vascular studies) and selected laboratory tests (he matology, basic biochemistry, and advanced biochemistry) for all patie nts discharged with selected medical and surgical diagnoses in 1990 an d 1991 from four university hospitals and four community hospitals in Canada (n = 6,491) and the United States (n = 7,980). Overall, US medi cal patients received 22% more diagnostic tests than their Canadian co unterparts (544.2 relative value units [RVUs] vs. 446.5 RVUs in Canada , P < 0.001), which was mainly the result of higher radiology use. Alt hough mean radiology use was 40% higher in the United States (370.0 vs . 264.5 RVUs in Canada, P < 0.05), there was little difference in the use of laboratory tests between countries (174.2 vs. 182.4 RVUs in Can ada P = 0.3). Within radiology, only CT and MRI use differed significa ntly between countries (US patients received 119% more tests than Cana dians). These findings were consistent after adjustments for age, gend er, diagnosis-related group, and university status. Differences in tes t use between countries were mainly the result of more testing among t he US elderly than counterparts in Canada. Among surgical patients, th ere was little difference between countries for radiology (76.3 vs. 67 .3 RVUs in Canada, P < 0.05) and laboratory (83.6 vs. 91.4 RVUs in Can ada, P < 0.05). Comparable inpatients admitted to US hospitals receive d more diagnostic tests than their Canadian counterparts even in hospi tals with similar availability of technology. Differences between coun tries were larger for high-cost tests than for lower-cost tests. Much of the difference in test use is explained by more intensive use for t he elderly in the United States.