http://www.nejm.org/doi/full/10.1056/NEJMcp1412652 https://www.nejm.org/doi/full/10.1056/NEJMcp1412652 advanced dementia http://www.nejm.org/doi/full/10.1056/NEJMcp1412652 http://www.nejm.org/doi/full/10.1056/NEJMcp1412652