PCR136 The Burden of Systemic Mastocytosis in Select European Countries: Evidence from the Prism Patient Survey. - Mesa, R.; Triggiani, M.; Hobart, J.; Green, T.; Powell, D.; Gressier-Sayag, C.; Baisley, W.; Lahue, B.; Rueff, F.; Schinhofen, W.; Hegmann, N.; Livideanu, C.; et al. (Value in Health, 2023)