title: Observational studies versus controlled clinical trials for efficacy & effectiveness of a drug.
authors.affiliation: Department of Community Medicine, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Kanica
authors.initials: K
authors.lastname: Kaushal
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Raina
mesh_terms: D000927:Anticonvulsants / Q000494:pharmacology*; D001569:Benzodiazepines / Q000494:pharmacology*; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male
chemical_list: D000927:Anticonvulsants; D001569:Benzodiazepines