Quality of life and discriminating power of two questionnaires in fibromyalgia patients: Fibromyalgia Impact Questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey.

BACKGROUND: Fibromyalgia is a painful syndrome characterized by widespread chronic pain and associated symptoms with a negative impact on quality of life. OBJECTIVES: Considering the subjectivity of quality of life measurements, the aim of this study was to verify the discriminating power of two quality of life questionnaires in patients with fibromyalgia: the generic Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the specific Fibromyalgia Impact Questionnaire (FIQ). METHODS: A cross-sectional study was conducted on 150 participants divided into Fibromyalgia Group (FG) and Control Group (CG) (n=75 in each group). The participants were evaluated using the SF-36 and the FIQ. The data were analyzed by the Student t-test (α=0.05) and inferential analysis using the Receiver Operating Characteristics (ROC) Curve--sensitivity, specificity and area under the curve (AUC). The significance level was 0.05. RESULTS: The sample was similar for age (CG: 47.8 ± 8.1; FG: 47.0 ± 7.7 years). A significant difference was observed in quality of life assessment in all aspects of both questionnaires (p<0.05). Higher sensibility, specificity and AUC were obtained by the FIQ (96%, 96%, 0.985, respectively), followed by the SF-36 (88%, 89% and 0.948 AUC). CONCLUSION: The FIQ presented the highest sensibility, specificity and AUC showing the most discriminating power. However the SF-36 is also a good instrument to assess quality of life in fibromyalgia patients, and we suggest that both should be used in parallel because they evaluate relevant and complementary aspects of quality of life.

Quality of life and discriminating power of two questionnaires in fibromyalgia patients: fibromyalgia Impact Questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey / A qualidade de vida e o poder de discriminação de dois questionários em pacientes com fibromialgia: fibromyalgia Impact Questionnaire e Medical Outcomes Study 36-Item Short-Form Health Survey

BACKGROUND: Fibromyalgia is a painful syndrome characterized by widespread chronic pain and associated symptoms with a negative impact on quality of life. OBJECTIVES: Considering the subjectivity of quality of life measurements, the aim of this study was to verify the discriminating power of two quality of life questionnaires in patients with fibromyalgia: the generic Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the specific Fibromyalgia Impact Questionnaire (FIQ). METHODS: A cross-sectional study was conducted on 150 participants divided into Fibromyalgia Group (FG) and Control Group (CG) (n=75 in each group). The participants were evaluated using the SF-36 and the FIQ. The data were analyzed by the Student t-test (α=0.05) and inferential analysis using the Receiver Operating Characteristics (ROC) Curve - sensitivity, specificity and area under the curve (AUC). The significance level was 0.05. RESULTS: The sample was similar for age (CG: 47.8±8.1; FG: 47.0±7.7 years). A significant difference was observed in quality of life assessment in all aspects of both questionnaires (p<0.05). Higher sensibility, specificity and AUC were obtained by the FIQ (96 percent, 96 percent, 0.985, respectively), followed by the SF-36 (88 percent, 89 percent and 0.948 AUC). CONCLUSION: The FIQ presented the highest sensibility, specificity and AUC showing the most discriminating power. However the SF-36 is also a good instrument to assess quality of life in fibromyalgia patients, and we suggest that both should be used in parallel because they evaluate relevant and complementary aspects of quality of life.

CONTEXTUALIZAÇÃO: A fibromialgia é uma síndrome dolorosa caracterizada por dor espalhada e crônica e sintomas associados com um impacto negativo na qualidade de vida. OBJETIVOS: Considerando a subjetividade da mensuração de qualidade de vida, o objetivo deste estudo foi avaliar o poder de discriminação de dois questionários que avaliam a qualidade de vida de pacientes com fibromialgia: o genérico Medical Short Form Healthy Survey (SF-36) e o específico Questionário do Impacto da Fibromialgia (QIF). MÉTODOS: Foi conduzido um estudo transversal com 150 indivíduos, divididos em dois grupos: grupo fibromialgia (FM) e grupo controle (GC) (n=75 em ambos). Os pacientes foram avaliados pelo SF-36 e pelo QIF. Na análise dos dados, utilizou-se o teste "t de Student" com α=0,05 e a Curva ROC (Receiver Operating Characteristics Curve). RESULTADOS: As amostras foram estatisticamente semelhantes para a idade - 47,8 (8,1) no GC e 47,0 (7,7) no FM - e estatisticamente diferentes em todos os aspectos dos dois questionários (SF-36 e QIF). Alta sensibilidade, especificidade e área abaixo da curva (AUC) foram obtidas com o QIF (96 por cento, 96 por cento, 0,985 respectivamente), seguido pelo SF-36 (88 por cento, 89 por cento e 0,948 AUC). CONCLUSÃO: O QIF mostrou-se mais discriminativo do que o SF-36 para avaliar a qualidade de vida de fibromiálgicos. No entanto, o SF-36 é também um bom instrumento de avaliação e sugere-se que ambos sejam usados uma vez que avaliam aspectos relevantes e complementares da qualidade de vida.