Abstract / Description of output
Objective: This study aimed to test the validity of the 36-item Short-Form Health Survey (SF-36) scales and summaries in patients with severe functional somatic syndromes (FSS), such as fibromyalgia and irritable bowel syndrome.
Study Design and Setting: One hundred twenty patients with severe FSS enrolled in a randomized controlled trial filled in the SF-36 questionnaire. We tested for data quality, central scaling assumptions, and agreement with the conceptual model.
Results: Most SF-36 scales were found to be valid; however, three scales (role physical, role emotional, and general health) did not satisfy predefined criteria for construct validity, internal consistency, or targeting to the sample. The correlations between SF-36 scales differed considerably from those reported in the general population. As a consequence, the SF-36 summaries, physical component summary (PCS) and mental component summary (MCS), did not accurately reflect their underlying scales and were negatively correlated (r = -0.46, 95% CI [-0.60 to -0.31]).
Conclusion: Although the SF-36 is a valuable instrument to assess perceived health in patients with severe FSS, there are problems with some of the scales and with the scoring procedure of the summaries. The SF-36 PCS may, therefore, not accurately measure the physical health status of these patients. Alternative summary measures are needed. (C) 2012 Elsevier Inc. All rights reserved.
Original language | English |
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Pages (from-to) | 30-41 |
Number of pages | 12 |
Journal | Journal of Clinical Epidemiology |
Volume | 65 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2012 |
Keywords / Materials (for Non-textual outputs)
- Quality of life
- Outcome measurement
- SF-36
- Physical component summary
- Validity
- Functional somatic syndromes
- QUALITY-OF-LIFE
- CHRONIC-FATIGUE-SYNDROME
- IRRITABLE-BOWEL-SYNDROME
- PRIMARY-CARE PATIENTS
- HEALTH SURVEY SF-36
- SHORT-FORM
- FIBROMYALGIA SYNDROME
- SCALING ASSUMPTIONS
- MULTIPLE-SCLEROSIS
- CONSTRUCT-VALIDITY