Translation & Cross-Cultural Adaptation of the Swedish Occupational Fatigue Inventory (SOFI) into Persian and Evaluation of its Face & Convergent Validity

The aim of the current study was to translate and cross-culturally adapt the Swedish Occupational Fatigue Inventory (SOFI) into Persian and to evaluate its face and convergent validity.Method & Material: A methodological study was performed according to standard IQOLA protocols, including the following steps: translating the SOFI questionnaire, evaluating the quality of the translation, back-translation and comparison of the English version with the Persian version by the original developer. The translated version was completed by 200 nurses. The Persian version of the Modified Fatigue Impact Scale (MFIS) questionnaire was used to evaluate the convergent validity. Spearman’s correlation was used to evaluate the correlation between the items. On the whole, the translations of the sentences were easy. The quality of the translation including the ‘clarity of translation, common language use, conceptual equivalence, and overall translation quality’ of the items was good. Face validity of the questionnaire was acceptable and did not lead to multiple changes in the questionnaire. Spearman’s correlation coefficient showed a high correlation between the total SOFI score and total (Persian) MFIS score (r=0.71 and p<0.01). The Persian version of the SOFI has acceptable face and convergent validity and is ready for further evaluation of its reliability.