effectiveness is determined first by scientific evidence, then by professional standards, then by expert opinion;9 and cost-effective for this condition compared to alternative interventions, including no intervention.10 “Cost-effective” does not necessarily mean lowest price.


Singer, S., L. Bergthold, C. Vorhaus, S. Olson, I. Mutchnick, Y. Y. Goh, S. Zimmerman, and A. Enthoven. 1999. Decreasing variation in medical necessity decision making. Appendix B. Model language developed at the “Decreasing Variation in Medical Necessity Decision Making” Decision Maker Workshop in Sacramento, CA, March 11-13, 1999.


9 For existing interventions, the scientific evidence should be considered first and, to the greatest extent possible, should be the basis for determinations of medical necessity. If no scientific evidence is available, professional standards of care should be considered. If professional standards of care do not exist, or are outdated or contradictory, decisions about existing interventions should be based on expert opinion. Giving priority to scientific evidence does not mean that coverage of existing interventions should be denied in the absence of conclusive scientific evidence. Existing interventions can meet the contractual definition of medical necessity in the absence of scientific evidence if there is a strong conviction of effectiveness and benefit expressed through up-to-date and consistent professional standards of care or, in the absence of such standards, convincing expert opinion.

10 An intervention is considered cost effective if the benefits and harms relative to costs represent an economically efficient use of resources for patients with this condition. In the application of this criterion to an individual case, the characteristics of the individual patient shall be determinative.

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