Alternative perspectives on the biased foundations of medical technology assessment.

Medical technology assessment seeks to improve the care of individual patients (the conventional unit of clinical practice) through evaluation studies conducted in groups of patients (the conventional unit of clinical investigation). This distinction between individuals and groups has practical relevance to the design, analysis, and clinical applicability of technology assessment studies. We define several biased perspectives about technology assessment that derive from the distinction between individuals and groups: a misguided emphasis on efficacy versus effectiveness, on statistical significance versus clinical importance, and on objective versus subjective outcomes. In each case, we contrast these alternative perspectives and speculate on their implications for health care policy.