Validation of the Fibromyalgia Survey Questionnaire within a cross-sectional survey.
The Fibromyalgia Survey Questionnaire (FSQ) assesses the key symptoms of fibromyalgia syndrome. The FSQ can be administrated in survey research and settings where the use of interviews to evaluate the number of pain sites and extent of somatic symptom intensity and tender point examination would be difficult. We validated the FSQ in a cross-sectional survey with FMS patients. In a cross-sectional survey, participants with physician diagnosis of FMS were recruited by FMS-self help organisations and nine clinical institutions of different levels of care. Participants answered the FSQ (composed by the Widespread Pain Index [WPI] and the Somatic Severity Score [SSS]) assessing the Fibromyalgia Survey Diagnostic Criteria (FSDC) and the Patient Health Questionnaire PHQ 4. American College of Rheumatology 1990 classification criteria were assessed in a subgroup of participants. 1,651 persons diagnosed with FMS were included into analysis. The acceptance of the FSQ-items ranged between 78.9 to 98.1% completed items. The internal consistency of the items of the SSS ranged between 0.75-0.82. 85.5% of the study participants met the FSDC. The concordance rate of the FSDC and ACR 1990 criteria was 72.7% in a subsample of 128 patients. The Pearson correlation of the SSS with the PHQ 4 depression score was 0.52 (p<0.0001) and with the PHQ anxiety score was 0.51 (p<0.0001) (convergent validity). 64/202 (31.7%) of the participants not meeting the FSDC criteria and 152/1283 (11.8%) of the participants meeting the FSDC criteria reported an improvement (slightly too very much better) in their health status since FMS-diagnosis (Chi(2) = 55, p<0.0001) (discriminant validity). The study demonstrated the feasibility of the FSQ in a cross-sectional survey with FMS-patients. The reliability, convergent and discriminant validity of the FSQ were good. Further validation studies of the FSQ in clinical and general population settings are necessary.
Department Internal Medicine I, Klinikum Saarbrücken, Saarbrücken, Germany. whaeuser@klinikum-saarbruecken.de
Winfried
W
Häuser
Eva
E
Jung
Brigitte
B
Erbslöh-Möller
Mechthild
M
Gesmann
Hedi
H
Kühn-Becker
Franz
F
Petermann
Jost
J
Langhorst
Thomas
T
Weiss
Andreas
A
Winkelmann
Frederick
F
Wolfe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult