Abstract
PURPOSE: This study aimed to translate the T-14 questionnaire into Swedish and validate it in a Swedish pediatric population with tonsil-related disease. METHODS: A prospective validation study was conducted across five Swedish otorhinolaryngology departments from October 2022 to June 2024. Translation followed a standardized forward-backward procedure. Caregivers of patients (< 16 years) scheduled for tonsil surgery completed the Swedish T-14 and EQ-5D-Y VAS (EuroQol five-Dimensional questionnaire for Youth, Visual Analog Scale [VAS]) at baseline, 2 weeks later, and 6 months postoperatively. A healthy control group was included for comparison. Psychometric evaluation included known-groups validity (Mann-Whitney U), construct validity (confirmatory factor analysis), convergent validity (Spearman's correlation), internal consistency (Cronbach's α), test-retest reliability (intraclass correlation coefficient), and responsiveness (Wilcoxon signed-rank, Cohen's d). RESULTS: A total of 249 participants were included (case group 169, control group 80). Known-groups validity was confirmed, with significantly higher baseline T-14 scores in the case group (p < 0.001). Confirmatory factor analysis supported the predefined two-factor model (comparative fit index = 0.94, Tucker-Lewis index = 0.92, standardized root mean square residual = 0.061), although root mean square error of approximation (0.099) indicated some misfit. Convergent validity was demonstrated by a weak but significant negative correlation with EQ-5D-Y VAS (rs = -0.32; p < 0.001). Internal consistency was good (α = 0.83), and test-retest reliability showed good stability (ICC = 0.77). Responsiveness was strong, with a large reduction in T-14 scores 6 months after surgery (p < 0.001; Cohen's d = 1.89). CONCLUSION: T-14 demonstrated good validity, reliability, and responsiveness, effectively distinguishing patients from healthy controls. It is suitable for clinical use and enables comparisons with international studies. LEVEL OF EVIDENCE: Level III-non-randomized controlled cohort.