title: Cohorts in economic comparison might not have been comparable.
authors.forename: Mike
authors.initials: M
authors.lastname: Thomas
mesh_terms: D018927:Anti-Asthmatic Agents / Q000191:economics*; D001249:Asthma / Q000188:drug therapy*; D015331:Cohort Studies; D016527:Drug Costs; D006801:Humans
chemical_list: D018927:Anti-Asthmatic Agents