MEASURING QUALITY-OF-LIFE IN PATIENTS WITH SCHIZOPHRENIA

Schizophrenia is a chronic disabling illness that affects about 1% of the population. It is a heterogenous disorder with variable aetiologic al, prognostic and treatment response patterns. Its course is generall y long term, with acute psychotic exacerbations that may require hospi talisation. The cornerstone of clinical management is the use of antip sychotic (neuroleptic) medications. Although these are effective, they can cause adverse effects that may impact negatively on the functiona l status of the individual. Early studies of quality of life in schizo phrenia were mainly concerned with the development of techniques to id entify patients' needs in the community. Difficulties encountered in t hese studies included: lack of agreement on definition of quality of l ife; lack of appropriate integrative conceptual models; concerns about reliability of patients' self-reports about their quality of life; an d the lack of standardised quality-of-life measures appropriate for sc hizophrenia. A number of disease-specific or generic scales have subse quently been used for measurement of quality of life in schizophrenia. The list of disease-specific scales is extensive; unfortunately, many of them were used only in a single study or their psychometric proper ties were not specified. Generic scales can be applied across Various types and severity of illness, as well as in different health interven tions across demographic and cultural groups. Medication costs in schi zophrenia represent only a small fraction of the total cost of the ill ness. However, pharmacoeconomic studies have attracted much interest a s a result of the high cost of newly introduced medications and of con cern about the limitations of antipsychotic medications, particularly their adverse effects, as exemplified by the reintroduction of clozapi ne for the treatment of refractory schizophrenia. Few studies have com bined quality-of-life measures with cost analysis in schizophrenia; a number of these have methodological shortcomings. Many studies are ret rospective in nature, and in most the number and length of hospitalisa tions has been used as the parameter for cost analysis, which can intr oduce bias depending on the varying approaches to hospitalisation. We conclude that the following factors are important in choosing or devel oping a quality-of-life measure for schizophrenia: quality of life is a multidimensional concept that has to be reflected in its measurement ; the scale has to be appropriate for the purpose as well as the popul ation studied;. measurement has to include patients' self-reports abou t their quality of life; measures should include only items that are r elevant and expected to change; single-item global measures are useful only when combined with multidimensional measures; in developing new scales, psychometric properties have to be established as well as bein g field-tested.