Costs were not discounted since only those costs incurred within a time horizon of 1 year after the start of the intervention were included in the analysis. Some quantities of resource use were reported separately from the costs. These included professional fees, investigation (laboratory tests, radiology, urodynamic), drugs, capital equipment, disposable equipment, and overheads. The costing was performed from the viewpoint of the Ministry of Health. Physicians' fees and laboratory costs were derived from the official fees from the Ontario Ministry of Health. In the estimation of common hospital costs as overhead expenses, heating, etc, two existing hospital models were used (per diem figures were used to value such costs). Hospital charts and official records were used to calculate the other components of costs. The costing was in 1994 Canadian dollars.