Reliability and validity of hip adduction strength to measure disease severity in XXXX .

@entity1 @entity2371 @entity158
STUDY DESIGN: A cross-sectional analysis was performed in @entity1 with @entity2371 ( @entity2371 ). The strength of adduction of the hips was measured and compared with the scores of commonly used disease severity measures of @entity158 . OBJECTIVES: To assess the reliability and validity of using hip adduction strength as measure of disease severity in @entity1 with @entity2371 . SUMMARY OF BACKGROUND DATA: Various tools are used to measure disease severity in @entity2371 ; there is still a need for simple tests with high reliability and validity. METHODS: Intra- and intertester reliability of hip adduction strength measurement was assessed in two small groups of @entity1 with @entity2371 . Validity of hip adduction strength to measure disease severity was investigated in a group of 200 @entity1 with @entity2371 by comparing the test scores with the medical history, scores on self-reported scales on disability, @entity158 , and tiredness, @entity158 provocation tests, and the active straight leg raise test. Responsiveness of hip adduction strength was assessed in a group of 75 @entity1 with @entity2371 . Global impression of improvement, scored by the @entity1 , was used as criterion standard. The responsiveness of the hip adduction strength was expressed as the standardized response mean and was compared with the responsiveness of the Quebec Back Pain Disability Scale. RESULTS: The intratester reliability for measuring hip adduction strength and the intraclass correlation coefficient were both 0.79. The intertester reliability for measurement of adduction strength and the intraclass correlation coefficient were also both 0.79. Hip adduction strength correlated as expected with all disease severity measures. Responsiveness of the hip adduction strength was large (standardized response mean = 0.93) and slightly less than that of the Quebec Back Pain Disability Scale (standardized response mean = 1.20). CONCLUSION: Hip adduction strength can be recommended to measure disease severity in @entity2371 , especially to describe groups of @entity1 and to evaluate the course of the disease in groups as well as in individual @entity1 . Decreased hip adduction strength appears to be caused by the inability to use the hip muscles rather than by weakness of the muscles.
