Spending for prescription drugs in the United States reached more than $200 billion or 12% of all healthcare expenditures in 2004 and has been one of the fastest growing components of healthcare spending.1,2
Medocare Part D drug on coverage will bring long-needed improvements in access to prescription drugs but is likely to increase expenditures further.
In the first months of Part D, seniors were offered 1429 stand-alone drug plans3
that were regulated and overseen by the Centers for Medicare & Medicaid Services.4
These plans had many formularies with a wide range of patent cost sharing,3
few of which have been rigorously evaluated regarding their clinical and economic outcomes. Well-designed patient cost-sharing policies5–8
as well as coverage restrictions9
have been shown to produce net savings from the health plan’s perspective10
without adversely affecting health outcomes. Other interventions that disregard clinical logic (eg, global physician budgets, prescription caps) can lead to unanticipated outcomes, including increased rates of hospitalization11
and nursing home admissions.12
The evidence is inconclusive for the common 3-tiered copayment systems.13,14
Generally these studies are criticized for their lack of generalizability because they were conducted in a wide range of patient populations and health systems. A direct comparison of several drug policies in a single system has not been published.
β-Adrenergic receptor blokers (β-blockers) are indicated for the treatment of hypertension15,16
and have e en shown to be as efficacious as calcium channel blockers17
and angiotensin-converting enzyme inhibitors17–20
in reducing blood pressure and cardiovascular risk. Oral β-blockers are further indicated for long-term use in all patients recovering from acute myocardial infarction (MI).21,22
Health plan performance measures like the Health Plan Employer Data and Information Set recommend β-blocker therapy after acute MI in patients who have no contraindications.23
β-Blockers treat a largely asymptomatic condition (hypertension) and may lead to side effects including fatigue, erectile dysfunction, and dizziness. Not surprisingly, adherence to antihypertensive treatment was less than 50% in elderly patients after 1 year, and only 20% of patients were sufficiently compliant to obtain the therapeutic benefits observed in clinical trials.24
Adherence was further reduced when β-blockers were combined with statin therapy.25
The rate of initiation of β-blocker therapy after acute MI was found to be less than 21% in a US Medicare population between 1987 and 1992.26
Spending for β-blockers was $2.1 billion among US seniors in 2001 according to an analysis of the Medical Expenditures Panel Survey.27
However, despite the fact that the efficacy of β-blockers has been proven, they are used in too few patients and with disappointing adherence even in the absence of cost sharing, which makes them a problematic target for any cost-sharing policy.
PharmaCare, the province-funded drug insurance plan in British Columbia, provided full prescription drug coverage for all elderly persons before January 2002. In January 2002, a prescription copayment policy for elderly residents of Can$25 (Can$10 for low-income seniors) was implemented. In May 2003, the seniors’ copayment was replaced with a 25% coinsurance payment plus an income-based deductible policy. Linking deductible cost-sharing levels to income was intended to prevent low-income patients from underutilizing essential drugs.28,29
This natural experiment among all elderly British Columbia residents provided the opportunity to evaluate the consequences of 2 subsequent patient cost-sharing interventions on adherence to β-blocker therapy among patients who initiated this therapy and on the initiation of β-blocker therapy after acute MI in a large, stable population of older adults.