Invasive composition for the evolution of a health information system

{I}n this paper we show that some of the evolution tasks in {O}pen{MRS}, a health information system, may require the invasive modification of interfaces and implementations in order to offer an appropriate modularization. {W}e introduce a new composition framework in {J}ava that supports the definition of expressive pattern-based invasive compositions. {F}ur thermore, we show that the composition framework allows us to concisely define an evolution scenario of {O}pen{MRS} that supports the consolidation of patient data from differ- ent remote instances.