Drugs to treat cardiovascular conditions top the list in both use and cost for public drug programs
Almost two-thirds (62%) of Canadians age 65 and older living in the community in six provinces are using five or more classes of prescription drugs, according to a study released today by the Canadian Institute for Health Information (CIHI).
The study, Drug Use Among Seniors on Public Drug Programs in Canada, 2002 to 2008, examined public drug claims for more than one million Canadian seniors in Alberta, Saskatchewan, Manitoba, New Brunswick, Nova Scotia and Prince Edward Island. The study found that in 2008, slightly more than one in five (21%) of these seniors were using 10 or more types of prescription drugs, and just more than 1 in 20 (6%) were using 15 or more different classes of drugs.
"Public-sector spending on prescribed drugs in Canada reached an estimated $11.4 billion in 2009, and we know that seniors account for a large portion of these expenditures," says Jean-Marie Berthelot, Vice President, Programs, CIHI. "With the aging of Canada's population, it is important to understand which drugs are being used most often by seniors and which account for the highest proportions of public drug program expenditure. This information helps to inform decisions about the future planning and delivery of public drug programs."
Older seniors were more likely to be multiple-drug users, with about one-third (29%) of seniors age 85 and older submitting claims for 10 or more types of drugs in 2008, compared to fewer than one in five (17%) seniors age 65 to 74.
Drugs for treatment of chronic illnesses most commonly used
CIHI's study shows a number of the most commonly used drug classes are for the treatment of chronic conditions in general, and cardiovascular conditions in particular, such as high blood pressure and heart failure. Examples of these drug classes include ACE inhibitors (for example, ramipril), beta blocking agents (for example, metoprolol), dihydropyridine calcium channel blockers (for example, amlodipine) and thiazide diuretics (for example, hydrochlorothiazide).
Statins (for example, atorvastatin), used to treat high cholesterol, were the most commonly used drug class among seniors younger than 85, with two out of five (40%) seniors age 65 to 84 using them. Statin use dropped in seniors age 85 and older, to about one in four (24%). ACE inhibitors, used to treat heart failure and high blood pressure, were the most commonly used among those 85 and older, used by almost one-third (32%) of these seniors. Proton pump inhibitors (for example, omeprazole), used to treat acid reflux disease, were another frequently used drug class.
"The prevalence of many chronic diseases increases with age, which may be contributing to the high number of drugs used by seniors," says Dr. Angela Juby, Associate Professor, Division of Geriatric Medicine at the University of Alberta. "Drug numbers per se are not as important as drug appropriateness. We know some chronic diseases, such as osteoporosis, are being under-treated. Therapy with multiple drugs is necessary to effectively manage chronic conditions; however, it is most important to consider the potential risks, including adverse effects and interactions between drugs or between drugs and diseases."
Top 10 drugs account for half of public program spending on seniors
The top 10 drug classes, in terms of drug program spending, accounted for almost half (48%) of public drug spending on seniors in the six provinces studied.
Public drug program expenditures were highest for statins, which accounted for 14% of total program spending on seniors. Proton pump inhibitors, used for acid reflux disease, accounted for the second-highest share, at 7% of total spending, followed by dihydropyridine calcium channel blockers, used for high blood pressure, which also accounted for 7% of total spending.
The drug class that experienced the fastest spending growth over the study period was tumour necrosis factor alpha inhibitors (anti-TNF drugs, such as etanercept), which treat conditions such as rheumatoid arthritis and Crohn's disease. Total drug spending on this class of drugs increased by an average of 58% annually from 2002 to 2008, and accounted for 2% of total program spending on seniors in 2008. The study also found that four of the fastest growing drug classes are used to treat cardiovascular conditions and two are used to treat chronic lung conditions like emphysema and chronic bronchitis.
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