The impact of AIDS-associated wasting on quality of life: qualitative issues of measurement and evaluation.

In 1987, wasting was designated an AIDS-defining condition by the Centers for Disease Control (Centers for Disease Control 1987). Defined conventionally as the involuntary loss of 10% or more of one’s premorbid weight, wasting has been observed as a primary feature of HIV disease since the first reports were filed documenting the clinical manifestations of this condition. The prevalence of wasting was reported to be approximately 17% through 1989 (Fleming et al. 1991); however, more recent clinical trials have documented that as many as 50% of people enrolled in AIDS studies have been found to have involuntary weight loss in excess of 10% of premorbid weight. The most recent reports find that wasting ranks as the second most frequent initial AIDS-defining condition in the United States and is diagnosed with equal frequency in men and women (Nahlen et al. 1993). As a cause of death wasting has increased from 3.6% to 13.7% during the period 19841995 as compared with pneumocystis carinii pneumonia which decreased from 28.6% to 3.8% (Kravik et al. 1997). The clinical and quality-of-life implications of AIDS wasting are striking. Loss of 10% of body weight at the time of AIDS diagnosis, moderate (.4.5 kg) weight loss prior to an AIDS diagnosis and failure to regain weight after acute infection are all associated with decreased survival. Increases in the rates of hospital admissions and diminished quality of life have also been reported (Cohan et al. 1992, Turner et al. 1994). The mechanisms by which wasting exerts its influence on mortality and morbidity have not been fully elucidated. Reductions in lean body mass are correlated with mortality, while loss of body fat does not show the same degree of association. Loss of lean body mass leads to weakness, organ failure, secondary immune dysfunction, general inanition and ultimately death. A body cell mass of ,30% is predictive of a survival rate of only 20% by about 15 months. This compares with over 70% survival at two years among individuals who maintain their lean body mass, an effect that is independent of CD41Tcell count. Treatments for AIDS-associated wasting have led to the development of new treatments for enhancing weight gains in chronically ill patients. However, the functional and qualityof-life impacts of these treatments have not been well studied. Changes in body composition, rather than changes in functional patient status, have remained the primary endpoint. Measures of exercise tolerance and muscle strength have been the focus of most studies purporting to evaluate physical function. However, the mechanisms by which changes in weight and body composition affect how a patient feels emotionally, how able he/she is to carry out daily activities, and how he/she responds to social relationships have not been studied systematically. Implications for associated changes due to wasting and quality of life can have important implications for evaluating the relative importance of the clinical significance of new therapies. This paper will report findings from four focus groups conducted on patients with AIDS-associated wasting and highlight conceptual and measurement issues important for evaluating the therapeutic impact of pharmacological agents on AIDS-associated wasting.