Validity of the EQ-5D in assessing and valuing health status in patients with schizophrenic, schizotypal or delusional disorders.
OBJECTIVE
The EQ-5D is a generic questionnaire generating a health profile and a single index score for health-related quality of life. This study aimed to analyse the discriminative ability and validity of the EQ-5D in patients with schizophrenic, schizotypal or delusional disorders.


METHODS
One hundred sixty-six patients with schizophrenic, schizotypal or delusional disorders (ICD-10 F2) completed the EQ-5D. Measures of quality of life (WHOQOL-BREF), utility (TTO), subjective (SCL-90R) and objective (PANSS, CGI-S) psychopathology, and functioning (GAF, GARF, SOFAS, HoNOS) provided comparison. Discriminative ability was analysed by assessing frequency distributions of EQ-5D scores. Validity of the EQ-5D self-classifier was analysed by assessing differences in related other scores grouped by response levels of EQ-5D items. Validity of the visual analogue scale (EQ VAS) and the EQ-5D index (UK social tariff) was analysed by assessing their correlation with all other scores.


RESULTS
Seventy-nine percent of respondents reported problems in at least one of the EQ-5D dimensions (anxiety/depression 57%, usual activities 45%, pain/discomfort 44%, self-care 29%, mobility 22%). The mean EQ VAS score/EQ-5D index was 65.7/0.71. The four most frequently reported EQ-5D health states covered 45% of all respondents. For almost all EQ-5D dimensions, different response levels were associated with significantly different scores of measures used for comparison. Correlation of EQ VAS score and EQ-5D index were largest with scores of subjective measures (SCL-90R: -0.50 and -0.73; WHOQOL mental subscore 0.62 and 0.58; always P<0.001).


CONCLUSIONS
The EQ-5D showed a moderate ceiling effect and seems to be reasonably valid in this patient group.
König
Hans-Helmut
HH
Health Economics Research Unit, Department of Psychiatry, University of Leipzig, 04317 Leipzig, Germany. hans-helmut.koenig@medizin.uni-leipzig.de
Roick
Christiane
C
Angermeyer
Matthias C
MC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003702:Delusions / Q000175:diagnosis* / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D004185:Disability Evaluation; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics / Q000706:statistics & numerical data; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D011795:Surveys and Questionnaires