A study published in October 2003 examined 22,312 people between the ages of 40 and 47 in Hordaland County, Norway. Questionnaires asked if they had ever smoked and whether they had multiple sclerosis or other diseases. Out of the 22,312 people, 87 had multiple sclerosis, and of these, twice as many were smokers as were nonsmokers. There was an average of 15 years from when the people started smoking to when they developed multiple sclerosis. Researchers will now look more closely at smoking as a possible risk factor for developing the disease.