HOW HAS EXTRACORPOREAL SHOCK-WAVE LITHOTRIPSY CHANGED THE TREATMENT OF URINARY STONES IN QUEBEC

Objectives: To determine the number of people who underwent treatment of urinary stones in Quebec before and after the introduction of extra corporeal shock-wave lithotripsy (ESWL) and to determine how the intro duction of ESWL influenced resource utilization. Design: Before-after study; data were obtained from administrative databases and hospital-b ased cost estimates. Setting: The 68 acute care hospitals in Quebec in which treatment of urinary stones is undertaken. Patients: Quebec res idents admitted to hospital for treatment of urinary stones between th e fiscal years 1984 and 1992. Outcome measures: Number of people treat ed for urinary stones per year, total number of procedures per year (i ncluding open surgery, percutaneous procedures, retrograde procedures and ESWL), and annual resources (including number of hospital bed-days and direct costs) for treatment of urinary stones used overall and in hospitals with and without ESWL services. Results: Over the study per iod the number of people treated for urinary stones increased by 59%. As well, the combined frequency of ESWL and surgery (the two main trea tment methods) increased by 107%. These increases were largely due to rates of treatment that grew by 52% among women and by 34% among men. The total number of hospital bed-days decreased by 28%, which reflecte d shorter hospital stays for ESWL. However, despite this decrease, the total direct annual costs were 7% higher in 1992 than in 1984 because of the increased numbers of people treated and procedures performed. In the three hospitals that offered ESWL the number of hospital bed-da ys and the direct costs of treating urinary stones increased by 49% an d $2.5 million respectively. In the 65 other hospitals these figures d ecreased by 41% and about $2.9 million respectively. Conclusions: Beca use of increased intervention rates the total cost of treating urinary stones has risen since the introduction of ESWL. The introduction of ESWL has also been associated with a shift in the use of resources for treating urinary stones to hospitals with a lithotriptor. The reasons for the increased intervention rates are unknown. However, given the possibility of negative health effects and the increased costs, studie s to determine whether the increased rates improve health outcomes are warranted.