Background: To create and validate a German version of the Tonsil and Adenoid Health Status Instrument (TAHSI) for evaluation of tonsillectomy outcome in adult patients with chronic or recurrent tonsillitis.
Subjects and methods: 46 healthy volunteers were assessed twice in a 6 week interval with the TAHSI questionnaire. Their results were compared with 45 patients suffering from chronic tonsillitis before tonsillectomy and 6 months following surgery. For internal consistency, Cronbach's alpha was calculated; to identify normal score values, the optimum cutoff between healthy and diseased individuals was identified with receiver operating characteristic analysis; and responsiveness was assessed using Guyatt's Responsiveness Index (GRI).
Results: Cronbach's alpha for all questions was 0.92. Test- retest intraclass correlation coefficient was 0.89 (95% confidence interval 0.80-0.94 p < 0.001). Mean score for the healthy individuals was 7.0 (95% confidence interval 4.2-9.7). The optimum cut off score between healthy and diseased was 20 with a sensitivity of 80% and a specificity of 90% to differentiate controls from tonsillectomy patients.
Conclusion: The TAHSI performed well in this validation tests and is considered a favorable instrument to evaluate the effectiveness of tonsillectomy in adults with chronic or recurrent tonsillitis.
Keywords: Chronic tonsillitis; Cronbach’s alpha; Guyatt’s responsiveness Index; Quality of life; Receiver operating characteristic analysis; Test-retest reliability.