A cohort study has examined the clinical and economic outcomes following plasma exchange (PLEX) and intravenous immunoglobulin (IVIG) in U.S. patients with myasthenia gravis (MG).

Patients were identified for the study from the Nationwide Inpatient Sample database for 2000–2005. The following findings were reported:

• Among 1606 hospitalised patients, the unadjusted mortality rate of MG crisis remained higher than those without crisis (0.44% vs. 4.44%, p < 0.001), as well as the unadjusted complication rate (26.36% vs. 11.23%, p < 0.001).

• MG crisis patients receiving PLEX had statistically significantly more complications than those receiving IVIG (30.06% vs. 14.79%, p < 0.001).

• Among the whole cohort, adjusted mortality and complication rates were not significantly different between the treatment groups (p > 0.05).

• Acute respiratory failure, major cardiac complications, and acute renal failure were associated with an increased mortality rate (p < 0.001).

• Age and respiratory failure were associated with an increased complication rate (p < 0.001).

• Length of stay was statistically significantly longer for MG (6 vs. 4 days, p < 0.001) and MG crisis (10 vs. 5 days, p < 0.001) patients receiving PLEX.

• Inpatient costs were higher for MG ($26,662 vs. $21,124, p < 0.01) and MG crisis ($53,801 vs. $33,924, p < 0.001) patients receiving PLEX.

The researchers conclude from these findings that “compared to PLEX, IVIG appears of similar clinical (mortality and complications) and perhaps of superior economic (length of stay and total inpatient charges) outcomes in the treatment of MG. Elderly and those with complex comorbid diseases including acute respiratory failure may be better treated with IVIG.”