Psychometric validation of Indonesian Truth-Telling Questionnaire (TTQ-70) in patients with cancer

Abstract Background A culturally adapted Indonesian Truth-Telling Questionnaire is needed to assess patients’ preferences for cancer-related disclosure. This study aimed to translate and culturally adapt the 70-item Truth-Telling Questionnaire (TTQ-70) and evaluate its measurement properties among Indonesian patients with cancer. Methods A cross-sectional study included 500 patients with cancer from three tertiary hospitals in Medan, Indonesia. Translation and cultural adaptation involved forward translation, reconciliation, back translation, expert review, and cognitive debriefing with 50 patients. Evaluation included item- and scale-level content validity indices, exploratory analysis of dimensionality, comparisons by sex and age, Cronbach’s alpha, and a two-week test–retest Pearson correlation in the pilot sample. Results Item-level content validity indices ranged from 0.80 to 1.00, and the scale-level index was 0.95. Exploratory analysis yielded seven dimensions, with a reported cumulative extracted variance of 74.44%; this structure has not been confirmed by confirmatory factor analysis (CFA). Women and participants aged < 60 years had higher total scores in unadjusted comparisons. Overall Cronbach’s alpha was 0.923, and the two-week test–retest correlation was 0.964. Conclusion The Indonesian TTQ-70 shows preliminary evidence of content validity, internal consistency, and short-term score consistency. The seven-dimension solution remains provisional. Further evaluation of factor retention, correlated-factor solutions, independent CFA, and score agreement is needed before routine use of the proposed subscales. Longitudinal studies are required to examine preference changes during the cancer trajectory.