title: Feasibility of using recipients of health promotional newsletters for post-marketing surveillance.
abstract: Achieving an adequate sample size is one of the major difficulties in performing post-marketing observational studies of health outcomes in persons taking specific drug preparations. We assessed the feasibility of recruiting participants for such a study of Cardizem CD from approximately 400,000 U.S. recipients of a health promotion newsletter. A three-page questionnaire was sent to a 2.5% random sample (n = 10,000) of recipients, stratified by geographic region. After two mailings, 2779 (28%) returned the questionnaire. Of the 2779 respondents, 2132 (77%) reported having high blood pressure. Eighty-seven percent indicated a willingness to participate in a long-term prospective study. In a multivariate model, calcium channel blocker (CCB) use was associated with a history of coronary heart disease, duration of hypertension medication use greater than 1 year, a rating of good or excellent hypertension care, higher systolic blood pressure, higher education level, family history of cardiovascular disease, and history of smoking. These results indicate that self-reported CCB users may be at greater risk of cardiovascular heart disease and that it is feasible to use health promotion newsletters as a source of participants in prospective studies of cardiovascular disease.
authors.affiliation: Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD, USA. lmead@wclch.jhu.edu
authors.forename: L A
authors.initials: LA
authors.lastname: Mead
authors.forename: D E
authors.initials: DE
authors.lastname: Ford
authors.forename: L H
authors.initials: LH
authors.lastname: Roht
authors.forename: C L
authors.initials: CL
authors.lastname: Beach
authors.forename: M J
authors.initials: MJ
authors.lastname: Klag
mesh_terms: D000368:Aged; D001794:Blood Pressure; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002318:Cardiovascular Diseases; D004110:Diltiazem / Q000627:therapeutic use*; D005240:Feasibility Studies; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D015999:Multivariate Analysis; D010506:Periodicals as Topic; D011358:Product Surveillance, Postmarketing / Q000379:methods*; D012494:Sampling Studies; D011795:Surveys and Questionnaires; D014481:United States
chemical_list: D002121:Calcium Channel Blockers; D004110:Diltiazem