The measurement of outcome in the treatment of acid-related diseases can be assessed against the background of various types of economic evaluation. Apart from endoscopic confirmation of healing (or nonhealing), the measurement of outcome has been based on recording separately the occurrence of various symptoms and possible adverse effects, as experienced and reported by the patients. Findings have been reported as the proportions of total patients who are free from some or all symptoms. These proportions may be noted in terms of prevalence or incidence.
However, unless one treatment dominates the others (is superior or at least is not worse) on all outcome measures, it is impossible to say conclusively which treatment is the best overall, provided of course that there is no difference between the treatments in the severity of symptoms and adverse effects.
Decision trees have been built to combine some outcomes. However, in the future, measurements that give a more complete picture of the combined severity of various symptoms and adverse effects need to be adopted. These should help to assess how quickly and to what degree the severity of disease is affected by treatment. The emerging guidelines for economic evaluations encourage the measurement of outcome prospectively in terms of quality of life and/or survival, since for most drugs the ultimate outcome of therapy is to improve them, and expressing them as quality-adjusted life-years (QALYs) gained. Quality-of-life measures potentially appropriate for QALY calculations in acid-related diseases (EuroQol Group 1988; Kaplan & Anderson 1988; Rosser & Kind 1978; Sintonen & Pekurinen 1993) are briefly reviewed. Further, the use of decision analysis is encouraged to ensure that all relevant outcomes and their possibly changing probabilities over time are considered and quantified. Expressing results as proportions and numbers achieving specified targets (success) is recommended, because they are relatively easy to incorporate into economic evaluation. The use of cost-benefit analysis based on the human capital approach is discouraged, since there may not be an economic loss or benefit to society through a patient's lack of, or return to, productive capacity.