A higher-order analysis supports use of the 11-item version of the Tampa Scale for Kinesiophobia in people with neck pain

Background. Despite increasing clinical and research use of the 11-item version of the Tampa Scale for Kinesiophobia (TSK-11) in people with neck pain, little is known about its measurement properties in this population. Objective. The purpose of this study was to rigorously evaluate the measurement properties of the TSK-11 when used in people with mechanical neck pain. Design. This study was a secondary analysis of 2 independent databases (N=235) of people with mechanical neck pain of primarily traumatic origin. Methods. The TSK-11 was subjected to Rasch analysis and subsequent evaluation of concurrent associations with the Neck Disability Index and a numeric rating scale for pain intensity. Results. The TSK-11 conformed well to the Rasch model for interval-level measurement, but less so for acute or nontraumatic etiologies. A transformation matrix suggested that small changes at the extremes of the scale are more meaningful than in the middle. Cross-sectional convergent validity testing suggested relationships of expected magnitude and direction compared with pain intensity and neck-related disability. The use of the linearly transformed TSK-11 led to potentially important differences in distribution of data compared with use of the raw scores. Limitations. The sample size was slightly smaller than desired for Rasch analysis. The 2 databases were similar in terms of symptom duration, but differed in pain intensity and age. Conclusions. The TSK-11 can be considered an interval-level measure when used in people with neck pain. It provides potentially important information regarding the nature of neck-related disability. Clinically important difference may not be consistent across the range of the scale.