Reliability and validity of the Persian adaptation of the Core Outcome Measure Index in patients with chronic low back pain

Background: The purpose of the study was to determine whether the Persian Core Outcome Measures Index (PCOMI) is reliable and valid in patients with chronic low back pain (CLBP). Methods: The Persian COMI was developed using forward-backward translational method. Subjects were100 patients with CLBP. Patients completed the PCOMI, Persian functional rating index, and visual analog scale. Fifty patients completed the PCOMI for the second time after 7days to evaluate test-retest reliability. Fifty healthy subjects participated to assess discriminant validity. Results: There was no ceiling or floor effect. Cronbach's alpha was 0.85. The construct validity coefficient was 0.72. The ICCagreement for test-retest reliability was 0.86. Pearson correlation for criterion validity was 0.70. The PCOMI discriminated between patients and healthy subjects. The standard error of measurement and the smallest detectable change was 0.75 and 2.1, respectively. Factor analysis extracted 1 component. Conclusions: The results support the reliability and validity of the PCOMI for assessing patients with CLBP. (C) 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.