Quality of life measurement and clinical practice in mental health: applications and correlations of quality of life instruments in Greek patients with schizophrenia

The evaluation of health related quality of life (HRQL) has gained great importance as a measure of social and clinical outcome in schizophrenia. It extends beyond mere assessment of symptoms, and is also used in needs assessment and population based studies. Several studies have explored the usefulness of such indicators in assessing the overall individual and social impact of mental health policy interventions or the introduction of new neuroleptic drugs. In Greece, there has been limited research on the evaluation of HRQL impact of antipsychotic drugs on patients with schizophrenia. In addition, more research is needed on the relationship between psychopathology and measures of quality of life. HRQL measurement for patients with schizophrenia has to address important methodological issues. The core domains of HRQL indicators include assessments of physical, social and psychological functioning, disease and therapy related symptoms and global assessment of health. Generic instruments, such as the SF-36 and EQ-5D have been used to provide HRQL estimates. Generic instruments allow for a global HRQL assessment and comparisons with other disease populations. However, in patients with schizophrenia, generic assessments should be accompanied by indices, which capture disease specific domains such as interpersonal relationships, instrumental role, intrapsychic foundations, disability assessments, etc. Disease specific scales are more sensitive in capturing HRQL changes, which result from organizational, clinical or pharmacological interventions. The combination of subjective and objective, as well as clinician assessed and patient reported outcomes measures provides a comprehensive HRQL assessment.

An open label, 52-week follow-up study of 170 patients is being conducted in 8 psychiatric wards in both psychiatric and general public hospitals in Greece. The objectives of the study are the following:

i) the assessment of the impact of quetiapine (Seroquel^®) on the quality of life of patients with schizophrenia for 1 year,

ii) the relationship between psychopathology and HRQL outcome measures, and finally,

iii) the possible correlation of the generic quality of life questionnaires with disease specific instruments

iv) the assessment of psychometric properties (validity, reliability, reproducibility and specificity) and the cultural adaptation of the Greek version of a schizophrenia specific HRQL instrument, the Quality of Life Scale (QLS).

The outcome measures explored in the study include:

i. the generic questionnaires SF-36, EuroQol-5D and WHO-DAS II,

ii. the disease specific questionnaire Quality of Life Scale (QLS), which has been translated, validated and launched for the first time in a Greek patient population

iii. the Positive and Negative Symptom Scale (PANSS),

iv. the Clinical Global Impressions (CGI),

v. the Brief Psychiatric Rating Scale (BPRS), and

vi. the Extrapyramidal Symptoms Evaluation (ESE, Simpson-Angus).

Based on the preliminary analysis of 6 months follow-up data from the study, the panel session addresses the following core questions:

To what extent does long term treatment with quetiapine improve the quality of life of patients with schizophrenia?

Does long term treatment with quetiapine improve the psychopathology of patients with schizophrenia?

How do HRQL indicators relate to changes in patients' psychopathology over time?

Is it feasible to compare generic with disease specific HRQL indicators in the assessment of HRQL of patients with schizophrenia?

What are the psychometric properties of the QLS scale? Is it a useful outcome measure for Greek schizophrenia patients?