Multiple Sclerosis and Several Demographic Characteristics, Family History of MS, and Month of Birth: A Case-Control Study

Background: Several factors have been reported as risk factors for multiple sclerosis (MS); however, the main causes of the disease are still unknown. A geographical area with a low MS incidence is Ahvaz, Iran. Objectives: The objective of this study was to evaluate the association of several demographic characteristics, family history, and birth month with MS in Ahvaz. Patients and Methods: This was a case-control study including 155 MS cases and 155 controls matched for age, sex, and residential status. The participants were selected randomly, using a systematic method, from the MS patients referred to the MS Society of Khuzestan (Iran). The data collection tool was a standardized questionnaire designed by the authors to assess demographic characteristics. Data were analyzed using descriptive statistics including mean, frequency, and standard deviation and inferential statistical tests including χ 2 , Fisher’s exact test, and logistic regression using SPSS version 19. Results: In both cases and controls, no significant associations were found between Arab ethnicity and incidence of MS, marital status and risk of MS in Ahvaz, or more than 15-year residency in Ahvaz, birth in Khuzestan, and month of birth and the risk of MS (P 0.05). However, there was a marginally significant association between living from birth to age 15 years in Ahvaz and MS (P = 0.05). Furthermore, there was an association between a family history of MS and the risk of MS in Ahvaz (P = 0.02), which was significant in univariate logistic regression (P = 0.006). Conclusions: The findings suggested that according to the ecological conditions of Ahvaz, a family history of MS may increase the risk of developing MS.