Relatively short term test re-test reliability of Neck Disability Index by long term test re-retest reliability method of Oswestry Disability Index in healthy office workers.

ABSTRACT

BACKGROUND: Assessment of local condition specific outcome measures in combination to obtain an idea about the disability status of the whole spine is a conventional method. Oswestry Disability Index (ODI) and Neck Disability Index (NDI) are two outcome measures used together. Test re-test reliability of ODI in healthy subjects has clinical importance and the test re-test reliability of NDI may have clinical significance. OBJECTIVE: The purpose of this study is to investigate the test re-test reliability of the NDI by using long-term test re-test reliability method of ODI on healthy office workers. METHODS: Participants who have no chronic neck pain history were included in the study. Subjects were assessed by the Turkish-NDI (e-forms) on 1st, 2nd, 4th, 8th, 15th, 30th days. 49 (20 female, 29 male) of 106 participants (57 female, 49 male) completed the study. Kolmogorov-Smirnov and Friedman tests were used. RESULTS: The difference between median score of each day (χ= 9.275, p > 0.05) was neither statistically nor clinically significant. CONCLUSIONS: NDI has test re-test reliability in healthy subjects over a 1-month time interval and the test re-test reliability is also valid in cases where both questionnaires are used in combination in this time interval.