title: Recruitment of participants through community pharmacies for a pharmacogenetic study of antihypertensive drug treatment.
abstract: OBJECTIVE
  To describe the design, recruitment and baseline characteristics of participants in a community pharmacy based pharmacogenetic study of antihypertensive drug treatment.
  
  
  METHODS
  Participants enrolled from the population-based Pharmaco-Morbidity Record Linkage System.
  
  
  METHODS
  We designed a nested case-control study in which we will assess whether specific genetic polymorphisms modify the effect of antihypertensive drugs on the risk of myocardial infarction. In this study, cases (myocardial infarction) and controls were recruited through community pharmacies that participate in PHARMO. The PHARMO database comprises drug dispensing histories of about 2,000,000 subjects from a representative sample of Dutch community pharmacies linked to the national registrations of hospital discharges.
  
  
  RESULTS
  In total we selected 31010 patients (2777 cases and 28233 controls) from the PHARMO database, of whom 15973 (1871 cases, 14102 controls) were approached through their community pharmacy. Overall response rate was 36.3% (n = 5791, 794 cases, 4997 controls), whereas 32.1% (n = 5126, 701 cases, 4425 controls) gave informed consent to genotype their DNA. As expected, several cardiovascular risk factors such as smoking, body mass index, hypercholesterolemia, and diabetes mellitus were more common in cases than in controls.
  
  
  CONCLUSIONS
  Furthermore, cases more often used beta-blockers and calcium-antagonists, whereas controls more often used thiazide diuretics, ACE-inhibitors, and angiotensin-II receptor blockers. We have demonstrated that it is feasible to select patients from a coded database for a pharmacogenetic study and to approach them through community pharmacies, achieving reasonable response rates and without violating privacy rules.
authors.affiliation: Department of Pharmacoepidemiology & Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences , University of Utrecht, PO Box 80082, 3508 TB Utrecht, The Netherlands.
authors.forename: Diane B M A
authors.initials: DB
authors.lastname: van Wieren-de Wijer
authors.forename: Anke-Hilse
authors.initials: AH
authors.lastname: Maitland-van der Zee
authors.forename: Anthonius
authors.initials: A
authors.lastname: de Boer
authors.forename: Bruno H Ch
authors.initials: BH
authors.lastname: Stricker
authors.forename: Abraham A
authors.initials: AA
authors.lastname: Kroon
authors.forename: Peter W
authors.initials: PW
authors.lastname: de Leeuw
authors.forename: O
authors.initials: O
authors.lastname: Bozkurt
authors.forename: Olaf H
authors.initials: OH
authors.lastname: Klungel
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy; D018579:Patient Selection; D010594:Pharmacies / Q000706:statistics & numerical data*; D010597:Pharmacogenetics / Q000379:methods*; D012107:Research Design / Q000706:statistics & numerical data*
chemical_list: D000959:Antihypertensive Agents