PubMed1987
In order to provide information for decision making regarding urolithiasis treatment programs for the population of the Central West Region (population 1.8 million) of Ontario, we conducted an incremental cost-effectiveness analysis of standard surgery, percutaneous ultrasonic lithotripsy, and extracorporeal shock wave lithotripsy for the removal of renal and ureteric stones. Estimates of costs and effects were calculated for a 5-year period, beginning in 1985. Direct medical costs estimated were fees, both professional and technical, operating costs, and hospitalization costs for standard surgery, percutaneous ultrasonic lithotripsy, and extracorporeal shock wave lithotripsy. Capital costs, opportunity costs, and depreciation were included for extracorporeal shock wave lithotripsy, but not for standard surgery or percutaneous ultrasonic lithotripsy, thus creating a bias against extracorporeal shock wave lithotripsy. All costs were expressed in 1985 Canadian dollars; both costs and effects from years 2-5 were discounted using a rate of 5%. The effects estimated were disability days. Failure rates, complication rates, length of hospital stay, and disability days were median values reported in the medical literature. Assuming 400 procedures per year (based on previous experience in the Central West Region), the total 5-year costs in millions of dollars, were 8.86 for standard surgery, 7.84 for extracorporeal shock wave lithotripsy, and 7.51 for percutaneous ultrasonic lithotripsy. Costs per procedure were 4,429 for standard surgery, 3,918 for extracorporeal shock wave lithotripsy, and 3,756 for percutaneous ultrasonic lithotripsy. The total disability days generated were 69,098 for standard surgery, 18,184 for percutaneous ultrasonic lithotripsy, and 9,092 for extracorporeal shock wave lithotripsy. Because standard surgery costs more and generates more disability days than either percutaneous ultrasonic lithotripsy or extracorporeal shock wave lithotripsy, it is clearly the least desirable alternative. At 400 procedures per year, the cost of each disability day averted by extracorporeal shock wave lithotripsy, compared to percutaneous ultrasonic lithotripsy, is $35.60. At 500 procedures per year, extracorporeal shock wave lithotripsy costs less and generates fewer disability days than percutaneous ultrasonic lithotripsy and is therefore the desired alternative. Sensitivity analyses demonstrate that cost effectiveness results are most affected by the number of procedures performed, the length of stay, and the number of disability days generated.