title: Observational studies of drug safety.
authors: Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA.
authors: A M
authors: AM
authors: Walker
authors: M J
authors: MJ
authors: Stampfer
mesh_terms: D002121:Calcium Channel Blockers / Q000009:adverse effects*; D004341:Drug Evaluation / Q000379:methods*; D006801:Humans; D009369:Neoplasms / Q000139:chemically induced*
chemical_list: D002121:Calcium Channel Blockers