Background and Objectives Fibromyalgia it is recognised as a chronic condition because of high morbidity. Usually classified as a disease by the absence of functional organic changes, the diagnosis is controversial and takes approximately 2 to 3 years to be established by a rheumatologist. To minimize this gap, as well as the negative impact on quality of life of patients and the socio-economic context of the country concerned can resort to the administration of validated questionnaires. They also facilitate the collection of reliable information and its comparison with international studies in the scientific community. The objective of this study is culturally adapt and validate the instruments The London Fibromyalgia Epidemiology Study Screening Questionnaire (LFESSQ) and Clinical New Fibromyalgia Diagnostic Criteria (NCFDC) for the Portuguese population with FM.
Materials and Methods We administered the English version of the Fibromyalgia Impact Questionnaire (FIQ - P) and Portuguese versions of the new LFESSQ NDFDC and a sample of 82 individuals, in which 51 had a clinical diagnosis of FM and 31 showed no turning administer the LFESSQ and NDFDC after 10 days. These new versions of cultural adaptation resulted according to the Guidelines of the ERGHO and were subjected to the study of its psychometric properties.
Results After obtaining the conceptual and semantic equivalence of translated versions of LFESSQ and NDFDC, these instruments have demonstrated good levels of reliability (Cohen's kappa of 0.78 and 0.88, respectively). Verified the construct validity by correlations with the FIQ (from 0.63 to 0.76 and for LFESSQ NCFDC). The results also showed that the instruments are sensitive, with values between 72.6% and 78.4%, and specific, with values between 93.4% and 96.8%.
Conclusion Portuguese versions of the LFESSQ and NCFDC for the Portuguese population with FM have clarity and understanding, construct validity and good levels of reproducibility. The instruments also showed sensitivity and specificity.