QL14
Effect of Coexisting Autoimmune Disorders on Clinical Outcome in Multiple Sclerosis Patients: An Analysis from National Inpatient Database
Growing literature proposed an association between Multiple sclerosis (MS) and autoimmune disorders. Research related to clinical outcomes in MS patients with coexisting autoimmune disorder has not been given sufficient attention. The resulting information gap adds further complexity to disease management.
Objectives:
The objective of this study was to determine whether coexisting autoimmune disorder impacts clinical outcome in MS patients.
Methods:
We classified our patients with the diagnosis of MS into two groups. MS group (without coexisting autoimmune disorders) and MS Plus group (with coexisting autoimmune disorders). We used Nationwide Inpatient Survey data files from 2006 -2010. We identified patients using ICD-9 diagnosis and procedure codes. We compare the rate of clinical outcomes (In hospital mortality, discharge to home, nursing facilities, length of stay and total charges) between MS and MS Plus group. All the in-hospital outcomes were analyzed after adjusting for potential confounders using multivariate analysis.
Results:
Of 115,120 patients with MS, 18796 (16%) were in MS Plus group. After adjusting for confounders, the odds of in-hospital mortality was significantly higher in MS group compared to MS Plus group (OR 4.67, 95% CI 1.44-15.06, p=0.009). After adjusting for confounders, the odds of discharge to nursing facilities was significantly higher in MS group compared to MS Plus group (OR 1.16, 95% CI 1.05-1.28, p=0.002). Length of stay (6 ±14 days vs. 4 ±13 days, p=0.02) and mean hospital charges ($27,940 ±$ 131,292 vs. $23,938 ±$ 70,836, p<.0001) were significantly higher among MS Plus group compared to MS group.
Conclusions:
We found a considerable increase in In-hospital mortality and discharge to nursing facilities in MS group compared to MS Plus group. One of the possible explanation is that a co-existing autoimmune disorder might directly decrease the inflammation of the MS. Other autoimmune diseases have effector T cells (Th17 or Th2 predominant) which are typically different from those of MS (Th1 predominant). It is understood that certain effector T cells can regulate the effect of other effector T cells, and the findings in this study suggest that a co-existing autoimmune disorder may in fact lessen the severity of the immune dysregulation of MS which leads to improved health outcomes. Other possible explanations of better outcome in the MS Plus group might be the use of chronic immunosuppressive agents in addition to MS immunotherapy, and multidisciplinary management.