Is a family equal to the sum of its parts? Estimating family-level well-being for cost-effectiveness analysis.

Cost-effectiveness (CEA) analysis of health interventions focuses primarily on individual-level costs and benefits. However, health interventions intended for individuals often have implications for other members of an individual's family and the overall functioning of the family. While researchers have assessed the effects of health interventions on multiple family members, CEA has not routinely incorporated measures of effectiveness or costs from multiple family members. We could imagine, however, that CEA might over- or under-estimate the effects of health interventions if they are limited to individuals targeted by the intervention. Family-level CEA would consider the well-being of and costs borne by multiple family members in response to an individual-level intervention, and potentially lead to more appropriate resource allocation. Using the health plan as a working frame of reference, we explore conceptual issues related to estimating effectiveness at the level of the family for use in CEA.