The neglected effects of lifestyle interventions in cost-effectiveness analysis

A review of cost-effectiveness and cost-utility analysis studies applied to health promotion, and lifestyle interventions in particular, indicates that many benefits and some risks of these measures are not considered in the analyses. This may bias the results and lead to a less than optimal use of available resources. The basic measure of health benefits has usually been mortality for a single disease, in spite of the fact that a change in lifestyle may well change the incidence of morbidity of other diseases as well. Beneficial effects on the incidence and duration of non-fatal diseases are often disregarded. Economic appraisals do not usually consider nonhealth related benefits or risks such as information, knowledge, satisfaction, anxiety, self-esteem, social and economic benefits in an appropriate way. These benefits or risks are often positive, but might also create negative reactions in the community. The impact of social diffusion, i.e. the fact that the living habits of individuals influence the lifestyle of their immediate environment, is another neglected, but not negligible effect of lifestyle interventions. Under some assumptions, the impact of the social environment on smoking behaviour can be estimated to about 20%, e.g. for ten people stopping smoking there will be two others who also stop, or do not start, smoking.