Acceptability and cross-cultural feasibility of a self-administered questionnaire on past exposure to putative environmental risk factors for multiple sclerosis

Background: The use of self-administered questionnaires to reliably assess exposures that occurred prior to disease onset is an essential data collection component in international multi-center case control studies. Objective: To test the acceptability and cross-cultural feasibility of a self-administered questionnaire to assess past environmental exposures, including childhood infections and infectious mononucleosis, vitamin D through diet and sunlight, and smoking in multiple sclerosis (MS) patients and healthy subjects (HS) in Norway, Italy, Serbia and Sweden. Methods: A six-page questionnaire was developed in English and then translated into Norwegian, Italian, Serbian and Swedish. MS patients and HS were asked to complete it and evaluate each question using scores of 1 (‘easy to understand, easy to answer’), 2 (‘easy to understand, difficult to answer’), 3 (‘easy to understand, impossible to answer’) and 4 (‘difficult to understand’). Results: Eighty one subjects from Norway (26 MS patients, 55 HS), 104 from Italy (23, 81), 40 from Serbia (11, 29), and 32 from Sweden (20, 12) completed and evaluated the questionnaire. Gender was known for 244 subjects, 72 men and 172 women (mean age 37.6 ± 10.5 years). Scores of 1 were reported by over 53% for recalled diet, over 70% for sun exposure, over 73% for childhood infections/comorbidity/ familiar disorders, and over 94% for smoking. Neither sex nor subject group was found to be related to the reported level of understanding/ difficulty. On some questions, older subjects reported more difficulty. Questions on recalled sun exposure were perceived to be more difficult by Norwegians. Conclusions: The questionnaire has proven to be cross-culturally acceptable and feasible to complete to the same degree in MS patients and HS, and is an appropriate tool for assessing the association between MS risk and past environmental exposure in large international case-control studies.