A validity and reliability study of the Turkish Checklist Individual Strength (CIS) questionnaire in musculoskeletal physical therapy patients

Abstract

Background and purpose

The aims of this study were the following: (1) to develop a Turkish version of the Checklist Individual Strength Questionnaire (CIS-T); (2) to evaluate the reliability and validity of the CIS-T; and (3) to compare the fatigue levels between musculoskeletal physical therapy patients and healthy subjects. Methods: The questionnaire was adapted to Turkish using a ‘back translation’ method. Fifty healthy subjects and 165 musculoskeletal physical therapy patients (128 outpatients and 37 inpatients) were evaluated. To validate the CIS-T, all participants answered both the CIS-T and the Short Form-36 (SF-36). The CIS was re-administered one week later for test–retest reliability. Results: The internal consistency reliability of the CIS-T was Cronbach's α = 0.87 and the interclass correlation coefficient reliability was r = 0.92. The item-discriminant validity ranged from r = 0.10 to 0.63. The correlations between the total scores of the scale and the subscale scores of the SF-36 were significant and negative (p < 0.01). The total CIS scores were significantly higher in musculoskeletal physical therapy patients (inpatients) than in healthy subjects, but there was no significant difference between musculoskeletal physical therapy patients (outpatients) and healthy subjects (p < 0.05). Conclusion: The CIS-T was a valid and reliable scale for assessing fatigue in physical therapy patients and the fatigue levels of musculoskeletal physical therapy patients were higher than those of healthy subjects.