Health care utilization before and after intensive care unit admission in multiple sclerosis

The incidence of intensive care unit (ICU) admission is elevated in the multiple sclerosis (MS) population but the reasons for this are incompletely understood, as are outcomes post-ICU admission. Among MS patients we examined the association between ICU admission and health care utilization in the year preceding admission, and compared health care utilization following ICU admission among persons with MS and persons from the general population.

We used population-based administrative data from Manitoba, Canada to identify 4237 MS cases of which 2547 were incident. We compared the incidence rates of ICU admission in the prevalent MS population according to health care utilization in the year before admission, adjusting for age, sex, comorbidity and socioeconomic status. Among incident cases of MS we compared rates of health care utilization after ICU admission to those in a matched general population cohort. We used generalized linear models adjusting for age, sex, socioeconomic status, region, comorbidity and utilization before admission.

Of 4219 prevalent MS cases, 222 (5.3%) were admitted to the ICU. After adjustment, any hospitalization in the prior year conferred an 80% increased incidence, and physician visits in the highest tertile and prescription costs in the highest quartile in the prior year each conferred a more than two-fold increased incidence of admission. Among 2547 incident cases of MS, 109 (4.3%) were admitted to the ICU and 93 survived their admission. Thirty-eight percent of the MS population were re-hospitalized in the year following admission, similar to the matched population (33.8%). Seven percent of both populations were readmitted to the ICU. The MS population had more hospital days after ICU admission than the matched population (adjusted RR 3.11; 95% CI: 1.34-5.90). After adjustment the number of physician visits did not differ between populations.

The incidence of ICU admission is higher among persons with MS who have higher prior health care utilization. Health care utilization remains high after ICU admission. Efforts to prevent ICU admission in this population are needed.