Validation of Tampa Scale for Kinesiophobia in patients with shoulder instability

Purpose: The Tampa Scale for Kinesiophobia (TSK) has been used to evaluate psychological outcomes in patients with low back pain, anterior cruciate ligament injuries, and other orthopaedic conditions, but no previous study verified the validity of TSK for patients with glenohumeral instability. The purpose of this study was to evaluate the measurement properties of the Tampa Scale of Kinesiophobia (TSK-13) in patients with glenohumeral instability. Methods: The present study was designed as an observational study that includes individuals with a diagnosis of pathological glenohumeral instability. All patients underwent a structured interview to collect information on personal socio-demographic and contextual characteristics at the time of enrolment. Kinesiophobia was assessed using the 13-item version of the TSK-13. The questionnaire is divided into two domains (subscales): activity avoidance (AA) and health anxiety (HA). Additionally, enroled patients were administered the American Shoulder and Elbow Society (ASES) score and the Western Ontario Shoulder Instability Index (WOSI) questionnaire. The validation of the TSK questionnaire was conducted according to the analysis plan outlined in the IQOLA project and current guidelines. Correlation analysis was performed between TSK and ASES and WOSI. Results: The study population consisted of 100 patients. The TSK-13 questionnaire showed no floor and ceiling effects; all the correlations between each question in a given domain and the score of the same domain showed a very significant correlation (p < 0.0001) with Pearson's correlation coefficient greater than 0.90. Regarding discriminant validity, for each domain, 100% of questions showed a higher correlation with the domain of belonging than with the other domains. Correlation analysis between the TSK and the other questionnaires showed a significant correlation between each domain (and the overall score of TSK-13 and ASES and WOSI questionnaires. The internal consistency was good for each domain and for the overall score (Cronbach's α = 0.874, 0.787, and 0.851 for AA and HA and the overall score, respectively). Test-retest reliability was excellent for both domains (ICCs = 0.927 and 0.878 for AA and HA domains, respectively), and the overall score (ICC = 0.915). Conclusion: Measurement properties of the TSK-13 in patients with glenohumeral instability were good to excellent in terms of validity and reliability. The TSK-13 is a valid and useful instrument to assess kinesiophobia in patients affected by glenohumeral instability. Level of Evidence: Level III, observational study.