Trends in antihypertensive drug prescriptions and physician visits in Canada between 1996 and 2006.
BACKGROUND
In 1999, the Canadian Hypertension Education Program (CHEP) was launched to develop and implement evidence-based hypertension guidelines.


OBJECTIVE
To determine temporal trends in antihypertensive drug prescribing and physician visits for hypertension in Canada, and correlate these trends with CHEP recommendations.


METHODS
Longitudinal drug data (Intercontinental Medical Statistics [IMS] CompuScript database; IMS Health Canada) were used to examine prescriptions over an 11-year period (1996 to 2006) for five major cardiovascular drug classes. The IMS Canadian Disease and Therapeutic Index database was used to determine trends in physician office visits for hypertension.


RESULTS
Prescriptions for antihypertensive agents increased significantly over the 11-year period (4054% for angiotensin receptor blockers, 127% for thiazide diuretics, 108% for angiotensin-converting enzyme inhibitors, 87% for beta-blockers and 55% for calcium channel blockers). Time series analyses demonstrated increases in the growth rate for all drug classes, with the greatest annual change in prescriptions occurring during the 1999 to 2002 time period (except in angiotensin receptor blockers). An increase in prescriptions for fixed-dose combination products occurred, which was temporally related to the change in CHEP recommendations encouraging their use in 2001. The proportion of physician office visits for hypertension increased significantly from 4.9% in 1995 to 6.8% in 2005 (P<0.001).


CONCLUSIONS
The largest increase in antihypertensive drug prescribing occurred in the period immediately following implementation of CHEP (1999 to 2002). Although prescribing rates are still increasing, the rate of change has decreased, suggesting that the treatment market for hypertension may be becoming saturated. The impact of these changes on blood pressure control and clinical outcomes remains to be determined.
Hemmelgarn
Brenda R
BR
Department of Community of Health Sciences, University of Calgary, Calgary, Alberta. brenda.hemmelgarn@calgaryhealthregion.ca
Chen
Guanmin
G
Walker
Robin
R
McAlister
Finlay A
FA
Quan
Hude
H
Tu
Karen
K
Khan
Nadia
N
Campbell
Norm
N
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000600:supply & distribution* / Q000627:therapeutic use; D002170:Canada / Q000453:epidemiology; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000453:epidemiology; D008875:Middle Aged; D009819:Office Visits / Q000639:trends*; D017063:Outcome Assessment, Health Care / Q000639:trends; D010349:Patient Compliance / Q000706:statistics & numerical data; D015995:Prevalence; D012189:Retrospective Studies
D000959:Antihypertensive Agents