// update object instance
ObjectData od = encounter.getObjectInstance().getData().get("participants");
logger.trace("od: " + od);
if(od != null) {
if(ep.getParticipant() instanceof BasicModelObject) {
od.removeValue("instance:" + ((BasicModelObject)ep.getParticipant()).getId());
}
else {
od.removeValue("label:" + ep.getLabel());
}