Translation, cross-cultural adaptation, and psychometric evaluation of the Persian (Farsi) version of the QoLAF (quality of life in patients with anal fistula) questionnaire

INTRODUCTION: The effective treatment of anal fistulas almost always requires surgical intervention, which could be accompanied by post-operative complications, and affect the quality of life of patients. This study aimed to cross-culturally adapt the Persian version of the Quality of Life in patients with Anal Fistula questionnaire and evaluate its validity and reliability. MATERIALS AND METHODS: Sixty patients with a mean age of 44 years ranging from 21 to 72 years entered the study. Forty-seven participants were men, and thirteen were women. After performing a scientific translation of the questionnaire based on Beaton’s guidelines for cross-cultural adaptation and after extensive reviews by experts and specialists, the final version of the questionnaire was obtained. Then, 60 questionnaires (100%) were filled out by the participants (n = 60) and retrieved during a 7 to 21-day period. Data were collected and analyzed. Finally, according to the obtained data, the validity and reliability of the questionnaire were calculated. RESULTS: Cross-cultural adaptation of the translated questionnaire was verified by the expert committee. The results showed perfect internal consistency (Cronbach alpha = 0.842), and external consistency (intraclass correlation coefficient = 0.800; P<0.001). Spearman correlation coefficient between test and retest was reported to be 0.980 (P-value <0.01), confirming the temporal stability of the translated questionnaire. The interrater reliability based on Cohen’s kappa coefficient also demonstrated a perfect degree of agreement between two peer variables (Kappa = 0.889; P<0.001). CONCLUSION: The Persian translation of the Quality of Life in patients with the Anal Fistula questionnaire was proven to be valid and reliable for the evaluation of the QoL of patients with anal fistula.