title: Retrospective studies and chart reviews.
authors.affiliation: Respiratory Care, Ellison 401, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA. dhess@partners.org
authors.forename: Dean R
authors.initials: DR
authors.lastname: Hess
mesh_terms: D016022:Case-Control Studies; D016021:Epidemiologic Studies; D006801:Humans; D012189:Retrospective Studies