Background The Fatigue Severity Scale (FSS), Pittsburgh Sleep Quality Index (PSQI) and Modified Health Assessment Questionnaire (mHAQ) are validated questionnaires that measure fatigue, sleep quality and function respectively. Research in the Maltese population, on systemic lupus erythematosus (SLE) requiring the use of these questionnaires, necessitates their translation and validation into the Maltese language.
Objectives The aim of the study is to translate, validate and perform cross-cultural adaptation of the FSS, PSQI and mHAQ into the Maltese language, according to the recommended methodology.1
Methods The original instruments were translated into Maltese by two translators whose mother language is Maltese. One of the translators had a medical background and was knowledgeable on the concepts being examined in the questionnaires; while the other did not. The two translated versions of the instruments were then compared and the discrepancies were resolved by reaching a consensus on the best Maltese version that reflects the underlying meaning of the original English version. The preliminary initial Maltese translations were then given to two other translators for back translation into English. English was the native language of these translators and they were totally blind to the original versions. The back translated English versions were then compared to the original English questionnaires and any discrepancies were highlighted. The equivalent statements in the Maltese translations were discussed and changes were made to reflect the original English versions more accurately. The pre-final Maltese translations were produced and pilot tested in a sample of 20 bilingual SLE patients to evaluate the clarity of the questionnaires. These 20 patients were also asked to fill in the original English version of the FSS, PSQI and mHAQ, seven days after filling in the Maltese versions. Psychometric testing was carried out to assess reliability of the translation, internal consistency and validity.
Results Reliability of the translation of the FSS, PSQI and mHAQ into Maltese was analysed by using Kendall's tau test for statements having an ordinal scale and Pearson's correlation test for variables having a metric scale. The p value for each statement in the FSS, PSQI and mHAQ was less than 0.05 showing that the reliability of the translated versions was satisfactory. Internal consistency of the Maltese translations was demonstrated using Cronbach's alpha. This was calculated to be 0.877 for the FSS, 0.859 for the PSQI, and 0.897 for the mHAQ. Validity of the Maltese translation of the FSS was assessed by its correlation with the visual analogue scale for fatigue using Pearson's Correlation test. Pearson's R value was 0.809 and the p value was <0.001 confirming a positive significant correlation.
Conclusions This study has confirmed the reliability and internal consistency of the translated English versions of the FSS, PSQI and mHAQ into Maltese. Moreover the validity of the Maltese version of the FSS has been shown. The Maltese translations can be finalised and used for research purposes.
Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine. 2000; 25(24): 3186–3191.
Disclosure of Interest None declared