Clinician-rated functioning and patient-rated quality of life in schizophrenia: Implications of their correspondence for psychopathology and side effects

Abstract

Past studies have found inconsistent associations between subjective and objective measures of quality of life (QOL) in schizophrenia. We hypothesized that this may be due to heterogeneity in the demographic and/or clinical variables inherent in the samples and we investigated this possibility. We stratified the patients according to a descriptive measure of correspondence between self-reported QOL and clinician-rated functioning. We then examined whether heterogeneous patterns existed among the subgroups in terms of demographic variables, symptom severity, associations between self-reported and clinician-rated psychopathology and associations between side effects, QOL and functioning. The subgroups significantly differed with respect to clinician-rated positive symptoms (F=3.075, p<.05), subjective symptoms (somatization, F=5.768, p<.01; obsessive-compulsive, F=3.885, p<.05; interpersonal sensitivity, F=8.278, p<.001; depression, F=9.368, p<.001; anxiety, F=6.909, p<.01; hostility, F=7.787, p<.01; phobic anxiety, F=9.551, p<.001; paranoia, F=5.304, p<.01; psychoticism, F=5.071, p<.01) and in- and outpatient ratio (Chi(2)=11.58, p<.01). Only the subgroup with relatively good correspondence between clinician-rated functioning and self-reported QOL showed significant low to moderate associations between the aforementioned measures and side effects. In addition, they showed similar levels of significant associations between the positive and subjective symptoms. In contrast, other discordant subgroups lacked overall associations between side effects, functioning and QOL as well as between subjective and objective measures of psychopathology. Low to moderate levels of correspondence between subjective QOL and objective functioning were partly supportive of the independence of the constructs. Insight is likely to be a mediating variable of the correspondence between self-report and clinician-rated measures and should be considered in studies using self-report measures.