Disability and mortality in a cohort of multiple sclerosis patients: a reapprasial.

The aim of the study was to evaluate how the natural history of multiple sclerosis (MS) had changed over a 15-year period. We compared disability and mortality in a cohort of 83 MS patients hospitalised in the Neurological Institute of Pavia, northern Italy, from January 1, 1990, to December 31, 1991, with a similar cohort of 52 patients analysed in the past. After the follow-up, an unfavourable course (death or relevant disability) was observed in 41% of the patients in the new cohort, compared to 63.5% of the patients in the old one. The percentage of deceased patients was reduced from 25 to 6%. The analysis of the pooled data of the two cohorts indicates a recent tendency of firstly hospitalised patients having a shorter disease duration and a lower disability level, which could explain the relevant decrease both in mortality and disability. The differences, therefore, could be attributed to an increased awareness of this kind of diagnosis in recent years, which bring forward patients affected by mild disability at the early stage of the disease. Finally, in accordance with the vast majority of the literature our findings confirmed that clinical factors, such as onset at a late age and a short interval between onset and secondary progression, increased the risk of an unfavourable course.