A case-control study of the association between socio-demographic, lifestyle and medical history factors and multiple sclerosis

Objective: The etiology of multiple sclerosis (MS) remains poorly understood. Sociodemographic characteristics may play important roles in its development. Methods: In a case-control study of MS, a total of 200 newly diagnosed MS patients and 202 frequency age- and sex-matched controls were studied. Results: A direct and significant association was observed between cigarette smoking and the risk of MS. Higher education seemed to reduce the risk of MS. Contact with cats was inversely associated with MS, particularly in males, whereas contact with caged birds increased the risk significantly, especially in females. A strong family aggregation of MS was observed among cases. A past history of trauma and eye problems appeared to pose a high risk of MS. Cases had a significant family history of eye problems, mumps, measles, rubella, cancer and auto-immune diseases. Conclusion: If smoking and history of certain infectious diseases increase the risk of MS significantly, they could be modified and avoided, thereby reducing the likelihood of being afflicted by MS.