Thirty-day readmissions in multiple sclerosis: An age and gender-based US national retrospective analysis.

Background: Hospital readmission rate is an important indicator of the quality of care, healthcare economic burden, and post-discharge care. Multiple sclerosis (MS) is a potentially progressive neurological disease predominantly affecting young women. The natural history of the disease involves intermittent relapses and/or accrued baseline disability overtime especially in older patients contributing to frequent hospitalizations. The readmission metrics for patients with MS have not been studied.

Objective: To estimate nationwide 30-day readmission (30-DR) rate among patients hospitalized with MS and to study the predictors of readmission based on age and gender.

Methods: This was a retrospective observational cohort study of patients hospitalized with primary discharge diagnosis of MS using 2013 Nationwide Readmission Database (NRD). The cases were identified by ICD 9-CM code (340) linked to MS diagnosis. We used patient unique identifiers 'NRD visit link' to identify MS index hospitalizations and readmissions. Age (<40 vs. >40 years) and gender-based analyses were performed using multivariable logistic regression adjusting co-variables to identify the patient/system-specific factors associated with 30-DR.

Results: The overall 30-day readmission rate (30-DRR) was 10.2%. No gender difference was seen in the readmission rates (men 10.7% vs. women 10.1%, p = 0.56); higher readmission rates were observed in older patients (11.2% vs. 8.8%; p = 0.0055). However, readmission cost was higher in younger age group (≈ $ 12,586 vs. ≈$ 11,827; p = 0.62) and among women (≈$ 12,217 vs. ≈$ 11,746; p = 0.75). The common causes of 30-DR were MS exacerbation (42.5%), sepsis (13.7%) and respiratory complications (7.3%). The predictors of higher 30-DRR in younger patients were diabetes (OR 1.87, p = 0.02), intravenous immunoglobulin (IVIG) use (OR 3.64, p = 0.016), and discharge to a nursing facility (OR 1.66, p = 0.03), whereas in older age group, higher Charlson-Deyo Comorbidity Index (CCI) (OR 1.15, p = 0.0057), and plasma exchange (PLEX) (OR 2.38, p = 0.03) were predictive of higher readmission rate. The longer length of stay (LOS) during index admission (OR 1.81, p = 0.03) in men and higher CCI (OR 1.15, p = 0.007) and intravenous immunoglobulin (IVIG) use (OR 2.27, p = 0.04) in women increased the odds of readmission.

Conclusion: The overall 30-day readmission rate among patients following hospitalization for MS was 10.2%. The readmission rate was higher in older (>40 years) patients. The common causes of readmission were MS exacerbation, respiratory complications, and sepsis. A higher systemic disease burden, longer length of stay, and treatment with IVIG and PLEX were associated with higher risk of readmission. The readmissions were associated with higher cost of care and longer LOS compared to index admissions highlighting the economic impact of readmissions. Future strategies to lower the risk of readmissions in patients with MS should focus on optimal management of medical co-morbidities and infections.