Impact of Clinical Trial Results on National Trends in α-Blocker Prescribing, 1996-2002

Abstract

Context Research on factors that influence prescribing patterns and the extent of change produced by clinical trial findings is limited.Objective To examine the changes in prescribing of ␣-blockers for hypertension treatment before and after the April 2000 publication of the unfavorable Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) early termination involving the study's doxazosin mesylate arm. Changes in prescribing were considered in the context of other potential concurrent influences on medication use between 1996 and 2002, including changes in ␣-blocker drug prices, generic conversion, drug promotion, and competition. Design, Setting, and PatientsUsing 2 national pharmaceutical market research reports published by IMS HEALTH, ␣-blocker prescription orders reported in the National Prescription Audit-a random computerized sample of about 20000 of 29000 retail, independent, and mail order pharmacies and mass merchandise and discount houses-and office-based physician ␣-blocker prescribing patterns reported in the National Disease and Therapeutic Index-a random stratified sample of about 3500 physician offices-were tracked.Outcome Measures Trends in physician-reported use of ␣-blockers and ␣-blocker prescribing and dispensing by US pharmacies.Results There were steady increases in ␣-blocker new prescriptions, dispensed prescriptions, and physician drug use from 1996 through 1999. There was a moderate reversal in these trends following ALLHAT early termination and subsequent publications in early 2000. Between 1999 and 2002, new annual ␣-blocker prescription orders declined by 26% (from 5.15 million to 3.79 million), dispensed prescriptions by 22% (from 17.2 million to 13.4 million), and physician-reported drug use by 54% (from 2.26 million to 1.03 million). Other potential influences did not appear to have contributed significantly to this decline although cessation of ␣-blocker marketing may have hastened the decline.Conclusions Modest yet statistically significant declines in the use of doxazosin and other ␣-blockers coincided with the early termination of the ALLHAT doxazosin arm. Although physicians responded to this new evidence, strategies to augment the impact of clinical trials on clinical practice are warranted.

Rapid Change in Prescribing Behavior in Hospitals Participating in Get With The Guidelines–Stroke After Release of the Management of Atherothrombosis With Clopidogrel in High-Risk Patients (MATCH) Clinical Trial Results

“…Our finding of rapid relinquishment of information in the setting of safety concerns is consistent with other studies, 8 including a study from a smaller US registry that reported a fall in aspirinϩclopidogrel use in the 3 months after MATCH publication. 9 These findings suggest that diffusion of knowledge is more effective when relative risks and potential harm, rather than potential benefits, are highlighted.…”

Antihypertensive Prescriptions for Newly Treated Patients Before and After the Main Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial Results and Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure Guidelines

“…21 Although data for the current study were not At least 3 previous studies have evaluated changes in antihypertensive prescription patterns from before to after publication of the main ALLHAT findings. [22][23][24] Stafford et al 22 reported 26% and 22% decreases in ␣-blocker orders and dispensed prescriptions, respectively, after the early termination of that randomization arm in ALLHAT in 2000. Two studies reported changes in antihypertensive prescription patterns after the publication of the main outcomes of ALLHAT in December 2002.…”

Changes in Antihypertensive Prescribing During US Outpatient Visits for Uncomplicated Hypertension Between 1993 and 2004

“…Other factors may include drug marketing, formularies, and drug price; a combination of these factors can act to mitigate the impact of guidelines on actual practice. 32,33 For instance, since the market entry of ACEIs and CCBs in 1980s, advertising for these drugs has increased dramatically, whereas that for diuretics has decreased sharply; physician prescribing subsequently increased for highly marketed drugs while decreasing for others. 32 In addition, when major brand drugs become available in generic form, market share often increases within 12 months for the generic form and decreases for the brand drug.…”