Feasibility of utility assessment by rating scale and standard gamble in patients with ankylosing spondylitis or fibromyalgia.
OBJECTIVE
To assess the feasibility of utility measurement in patients with ankylosing spondylitis (AS) or fibromyalgia (FMS). Patient derived utilities provide overall estimates of the impact of a disease on patient well being.


METHODS
The Maastricht Utility Measurement Questionnaire was applied cross sectionally to 57 patients with AS and 86 outpatients with FMS. By means of rating scale and standard gamble techniques, patients were asked to value their own health state.


RESULTS
All 143 patients completed the interview. Patients with AS valued their personal health state on the rating scale (0-100) considerably higher than patients with FMS (AS: 69 and FMS: 54). Standard gamble utility values (0-1), however, were about the same at a higher level (AS: 0.86 and FMS: 0.83). Four weeks test-retest reliability was examined in 15 patients with FMS. The intraclass correlation coefficient of the utility score for the patient's own health state was 0.56 for the rating scale and 0.66 for the standard gamble technique.


CONCLUSIONS
Feasibility of the Maastricht Utility Measurement Questionnaire was generally satisfactory in both patient groups. Utility values obtained by rating scale and standard gamble technique differed considerably. Our data support the view that utility measurement is sensitive to the method chosen to elicit patient well being.
Bakker
C
C
Department of Internal Medicine, University of Limburg, Maastricht, The Netherlands.
Rutten
M
M
van Doorslaer
E
E
Bennett
K
K
van der Linden
S
S
D000203:Activities of Daily Living; D000328:Adult; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology / Q000523:psychology*; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D013167:Spondylitis, Ankylosing / Q000503:physiopathology / Q000523:psychology*; D011795:Surveys and Questionnaires