when a patient feels distress, health care needs do not always correlate with health care system definitions (Evans and Stoddard, 1990).
Although disease usually is regarded as a binary variable—it is either present or absent—most health problems fall on a continuum. Changing the thresholds associated with a disease can thus change the number of people who would be considered sick. For example, in the past, “overweight” was defined as a body mass index greater than 28. When that threshold recently was reset at 25 (NHLBI, 1998), most of the adult U.S. population became classified as overweight. Similarly, new methods for assessing subthreshold depression greatly increased the number of people characterized as having that condition (Judd et al., 1996). Although slightly more than 5% of patients in general medical practice qualify for a diagnosis of depression, as defined by the American Psychiatric Association in its DSM-IV (APA, 1994), more than 25% meet the criteria for “subsyndromal” depression (Wells, 1996).
An alternative to the traditional biomedical model, the “outcomes model,” emphasizes patient outcomes rather than disease pathologies. The biomedical model is predicated on finding specific biological problems; the outcomes model considers consequences from the perspective of the patient. Successful treatments improve quality of life or extend length of life. This might differ significantly from what would be considered successful treatment using strictly biomedical measures. One review (Fowler et al., 1994), for example, found that although many surgical procedures have no effect on life expectancy, they can help relieve symptoms and improve functional status. Outcomes assessment is useful to determine whether symptoms are, in fact, relieved. A growing body of work demonstrates that measures of wellness are significant predictors of longevity for patients with chronic illnesses (Coates et al., 1997; Idler and Benyamini, 1997; Kaplan et al., 1994). Typically, simple self-report measures of overall health status perform at least as well as physiological indicators do.
Contemporary definitions recognize that health is multidimensional. Spilker (1996) identified five major domains of life quality: physical status and functional ability, psychological status and well-being, social interactions, economic and vocational status and factors, and religious and spiritual status. Various health outcomes approaches assess different dimensions, and the dimensions themselves vary considerably in approach. An emerging consensus suggests that the concept of health must integrate mortality with multiple dimensions of life quality. Most attempts include physical and mental symptoms of behavioral and social functioning.