Abstract
IntroductionThe Fibromyalgia Impact Questionnaire (FIQ) is a composite disease-specific measure validated for fibromyalgia (FM), but it is rarely used in clinical practice. The objective was to develop and analyse the psychometric properties of a new composite disease-specific index (Fibromyalgia Assessment Status, FAS), a simple self-administered index that combines a patient's assessment of fatigue, sleep disturbances and pain evaluated on the basis of the 16 non-articular sites listed on the Self-Assessment Pain Scale (SAPS) in a single measure (range 0 to 10).MethodsThe FAS index was constructed using a traditional development strategy, and its psychometric properties were tested in 226 FM patients (209 women, 17 men); whose disease-related characteristics were assessed by means of an 11-numbered circular numerical rating scale (NRS) for pain, fatigue, sleep disturbances and general health (GH), the tender point score (TPS), the SAPS, the FIQ, and the SF-36. A group of 226 rheumatoid arthritis (RA) patients was used for comparative purposes. Of the 179 FM patients who entered the follow-up study, 152 completed the three-month period and were included in the responsiveness analyses. One hundred and fifty-four patients repeated the FAS questionnaire after an interval of one week, and its test/re-test reliability was calculated. Responsiveness was evaluated on the basis of effect size and the standardised response mean.ResultsThe FAS index fulfilled the established criteria for validity, reliability and responsiveness. Factor analysis showed that SAPS and fatigue contributed most, and respectively explained 47.4% and 31.2% of the variance; sleep explained 21.3%. Testing for internal consistency showed that Cronbach's alpha was 0.781, thus indicating a high level of reliability. As expected, closer significant correlations were found when FAS was compared with total FIQ (rho = 0.347; P < 0.0001) and the FIQ subscales, particularly job ability, tiredness, fatigue and pain (all P < 0.0001), but the correlation between FAS and the mental component summary scale score (MCS) of the SF-36 (rho = -0.531; P < 0.0001) was particularly interesting. Test/re-test reliability was satisfactory. The FAS showed the greatest effect size. The magnitude of the responsiveness measures was statistically different between FAS (0.889) and the FIQ (0.781) (P = 0.038), and between the SF-36 MCS (0.434) and the SF-36 physical component summary scale score (PCS) (0.321) (P < 0.01).ConclusionsThe self-administered FAS is a reliable, valid and responsive disease-specific composite measure for assessing treatment effect in patients with FM.
Highlights
Introduction The Fibromyalgia ImpactQuestionnaire (FIQ) is a composite disease-specific measure validated for fibromyalgia (FM), but it is rarely used in clinical practice
The Fibromyalgia Assessment Status (FAS) index was constructed using a traditional development strategy, and its psychometric properties were tested in 226 FM patients (209 women, 17 men); whose disease-related characteristics were assessed by means of an 11-numbered circular numerical rating scale (NRS) for pain, fatigue, sleep disturbances and general health (GH), the tender point score (TPS), the Self-Assessment Pain Scale (SAPS), the Fibromyalgia Impact Questionnaire (FIQ), and the SF-36
We evaluated a sample of 226 patients meeting the American College of Rheumatology (ACR) criteria for rheumatoid arthritis (RA) [20], who were randomly matched from 469 RA patients participating in an ongoing longitudinal outcome project and reflected the age/gender-related stratification/distribution of the FM sample, and underwent the same complete clinical assessment with the fibromyalgia tender points assessment but the FIQ was not administered [12,21]
Summary
Introduction The Fibromyalgia ImpactQuestionnaire (FIQ) is a composite disease-specific measure validated for fibromyalgia (FM), but it is rarely used in clinical practice. The objective was to develop and analyse the psychometric properties of a new composite disease-specific index (Fibromyalgia Assessment Status, FAS), a simple self-administered index that combines a patient's assessment of fatigue, sleep disturbances and pain evaluated on the basis of the 16 non-articular sites listed on the Self-Assessment Pain Scale (SAPS) in a single measure (range 0 to 10). The aim of this study was to develop and analyse the psychometric properties of a new composite disease-specific index for evaluating patients with FM, Fibromyalgia Assessment Status (FAS), which includes domains/items considered relevant by patients and doctors. When evaluating the effectiveness of FM therapy, it is important to be able to assess its impact on all of the domains considered important by clinicians and patients [7,8], and the OMERACT (Outcome Measures in Rheumatology) Fibromyalgia Syndrome Workshop has recently completed an attempt to include the patient perspective in identifying and prioritising such domains using focus groups and Delphi exercises [1,8,9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
