Costs and quantities of the resources were not reported separately. Direct costs related to health care payers. More precisely the following costs were included: drugs, physician visits, tests, procedures and hospital stays due to the treatment of any drug-related adverse effects.
Reduced hospital costs (due to reduced side effects,for example, gastrointestinal) were also considered for lesions > 0.5cm. However, the probabilities for lesions requiring treatment (>0.5cm) were reduced by a factor of 40% to account for the lower expected number of lesions discovered under routine (not endoscopically) clinical practice. Allowance was made for cases in which patients switched from one NSAID to another as a result of adverse events.
Costs were based on various sources: for example, 1992 price list for drugs, 1992 DRG reimbursements, published studies and official data for the treatment of adverse events. Final costs were calculated using a decision tree.