S1 Data -

Objective
Transcultural adaptation and validation of FACIT-TS-PS questionnaire to Serbian language.
Methods
Standard forward and backward translation from English to Serbian language was performed. Pilot testing of FACIT-TS-PS was conducted on 12 patients with a confirmed diagnosis of malignant tumor. The study included 154 patients with malignant disease. The Questionnaire of Patient Satisfaction was used as a validated tool to evaluate concurrent validity of FACIT-TS-PS questionnaire. Reproducibility was tested on 30 subjects who answered the questionnaire for the second time two weeks later.
Results
Three FACIT-TS-PS subscales (Physician Communication, Treatment Staff Communication and Nurse Communication) demonstrated satisfactory construct validity using Cronbach’s alpha, the remaining two subscales (Technical Competence and Confidence & Trust) showed high ceiling effect. Treatment Staff Communication subscale showed large floor effect. Concurrent validity was demonstrated by correlation with the two dimensions of the Questionnaire of Patient Satisfaction. Satisfactory reproducibility was demonstrated on 30 patients who filled the questionnaire for the second time two weeks after initial interview.
Conclusion
The Serbian version of FACIT-TS-PS with the omission of Treatment Staff Communication subscale could be used as a valid instrument to assess patient and treatment satisfaction in chronically ill patients in the Serbian population. Omission of Treatment Staff Communication subscale is necessary because it contains questions not relevant for patients in Serbian healthcare system.