QUALITY-ADJUSTED SURVIVAL ANALYSIS - A NEGLECTED APPLICATION OF THE QUALITY OF WELL-BEING SCALE

Background: In survival analysis, those who are alive are statisticall y coded as 1.0 while those who are dead are coded as 0.0. Since everyo ne who remains alive is given the same score, a person confined to bed with an irreversible coma is alive and is counted the same as someone who is active and asymtomatic. The Quality of Well-being (QWB) scale defines levels of wellness on the continuum between death and optimum function and integrates morbidity and mortality into the same number. This paper demonstrates the effect of including mortality in QWB estim ates for male adults with HIV infection. Method This study involves fo llow-up of a cohort of 386 male adults participating in the San Diego HIV Neurobehavioral Research Center (HNRC). Patients were evaluated us ing the QWB at enrollment and at six month intervals. All patients wer e classified into three stages of HIV disease according to the Center for Disease Control (CDC) classification: CDC IV (symptomatic HIV dise ase), CDC II or III (asymptomatic infection) and uninfected male contr ols. Results: QWB scores were calculated with and without mortality in cluded for men in each CDC class who completed a one year (N = 148) or two year follow-up (N = 60). At each evaluation, there were significa nt differences among CDC classes and inclusion of deaths increased the variance accounted for by CDC class at each evaluation. Conclusions: HIV infection has significant impacts upon both morbidity and mortalit y. Survival analysis captures only the mortality dimension, while qual ity adjusted survival analysis using the QWB includes both dimensions. We propose quality adjusted survival analysis as a more sensitive met hod for assessing outcome in HIV disease and other health conditions.