Evidence-based medicine, utilities, and quality of life.
Evidence-based medicine provides the highest quality of information for medical practitioners. At the top of the pyramid of evidence-based medicine are the prospective, randomized clinical trials and meta-analysis. Evidence-based medicine can be incorporated with quality-of-life parameters; the latter can be quantified using utility theory. With utility theory, utility values range from 0.0 (death state) to 1.0 (perfect health state). The higher the utility value, the better a person's quality of life. Interventional treatment can change the utility level experienced by a patient. A change in utility value induced by an interventional treatment can be amalgamated with the duration of the treatment effect to provide the number of quality-adjusted life-years (QALYs) gained by a specific treatment (QALYs = [gain in utility value] x [duration of treatment effect]). Thus, this formula takes into account both the improvement in quality of life and the improvement in length of life gained by a treatment. The number of QALYs gained by a treatment can then be incorporated with medical costs (discounted for the time value of money) to arrive at a final common denominator of $/QALY (cost per QALY). The parameter $/QALY can be used to compare the cost-effectiveness of interventional treatments across diverse specialties in medicine. In essence, this methodology allows a measure of the cost-effectiveness of a treatment that incorporates the highest quality of scientific information, clinical efficacy, patient quality-of-life preferences, and realistic costs.
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Cataract and Primary Eye Care Service, Wills Eye Hospital, Philadelphia, Pennsylvania, USA.
Brown
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Sharma
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Garrett
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D000368:Aged; D003362:Cost-Benefit Analysis; D019317:Evidence-Based Medicine / Q000191:economics / Q000379:methods*; D006801:Humans; D008268:Macular Degeneration / Q000628:therapy; D008297:Male; D011788:Quality of Life