title: Prescribing patterns for thiazide diuretics in a large health maintenance organization: relationship to participation as an ALLHAT clinical center.
abstract: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) published its main findings in December, 2002. It recommended thiazide diuretics as a first-line treatment of hypertension. The current study describes the prescribing patterns of thiazide diuretics in four regions of Kaiser Permanente, a large national United States Health Maintenance Organization--two regions that had an ALLHAT clinical center and two that did not. We tested the hypothesis that participation in a clinical trial leads to quicker and greater adoption of study recommendations than non-participation in a trial. The relative percentage of filled outpatient prescriptions for the period 2 or 3 years before the ALLHAT main publication through December 31, 2004 was calculated by region for thiazide-type diuretics and for calcium channel blockers (CCBs), beta-blockers, central alpha-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and other antihypertensive diuretics. In the 2 years after publication of the ALLHAT trial findings, the percentage of all prescriptions for thiazide diuretics increased from 11.2% to 12.4% in the two regions with an ALLHAT clinical site and from 8.9% to 10.1% in the two regions without an ALLHAT clinical site (p > 0.05). The percentage of new prescriptions for thiazide diuretics increased from 13.7% to 16.6% in the two regions with an ALLHAT clinical site and from 10.8% to 13.0% in the two regions without an ALLHAT clinical site (p > 0.05). Participation in a clinical hypertension study does not appear to accelerate adoption of study recommendations.
authors.affiliation: Kaiser Permanente Southern California, 393 E. Walnut Street, Pasadena, 91188, USA. Diana.b.petitti@kp.org
authors.forename: Diana B
authors.initials: DB
authors.lastname: Petitti
authors.forename: Fagen
authors.initials: F
authors.lastname: Xie
authors.forename: Joshua I
authors.initials: JI
authors.lastname: Barzilay
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D004059:Diffusion of Innovation; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use*; D014481:United States
chemical_list: D000959:Antihypertensive Agents; D049993:Sodium Chloride Symporter Inhibitors