A comparison of the determinants of subjective and objective quality of life in schizophrenic illness [Abstract]

Background: Conceptually quality of life is a broad term and consists of a sense of well-being, life satisfaction and access to resources and opportunities. Methods: A subjective quality of life measure, the Lancashire quality of life scale(Oliver, 1991) was compared with an objective measure, the Heinrichs quality of life scale (Heinrichs et al,1884) in 75 subjects entering a randomised controlled trial comparing conventional and new atypical antipsychotics and clozapine.
Results: A significant correlation was found between the two scales (r = 0.386 p <0.01). Determinants of subjective and objective quality of life were explored using multiple regression analyses. The main determinants of subjective quality of life were depression measured on the Calgary Scale, insight(Birchwood Scale) and non-neurological side-effects, which together explained 44% of the variance p <0.01. Depression was responsible for 34% of this variance. In contrast, the main determinant of objective QLS were PANSS negative score and PANSS total score. These two together explained 51% of the variance with PANSS negative accounting for most 46% of this p <0.01.
Conclusion: The choice of subjective or objective quality of life measures is likely to reflect different dimensions of outcome, reflecting the underlying psychopathology of schizophrenia as opposed to measuring a discrete construct. A value judgement must therefore be made as to which of these measures best encapsulates what is meant by quality of life in schizophrenic illnesses.