Prevalence of Hypertension

Among continuously enrolled Medicare fee-for-service beneficiaries, the 2009 annual prevalence of hypertension was 60.1 percent (see Data Source and Definitions and Methods sections for definitions of continuous enrollment and hypertension). This number increased significantly when the cohort was restricted to Medicare beneficiaries with diabetes, who had an annual prevalence of hypertension nearly 1.5 times as high (87.6 percent) for 2009.

The annual prevalence of hypertension differed with regard to demographic factors, such as age, gender, and race/ethnicity. For example, in 2009, hypertension was more common among females than males (62.2 percent versus 56.8 percent) and in beneficiaries ages 65–74 (65.7 percent) and 75–84 (67.8 percent) compared with those under 65 (48.1 percent) and 85+ (52.7 percent). Variation in the prevalence of hypertension was also seen between races (white, 59.3 percent; black, 64.4 percent; Asian, 67.5 percent; Hispanic, 60.2 percent; American Indian/Alaska Native, 54.7 percent; and other, 62.1 percent).

Utilization of Antihypertensive Drugs Among Those With Hypertension

Between 2007 and 2009, 87 to 88 percent of beneficiaries with hypertension used an antihypertensive drug (Table 1). The use of an antihypertensive drug was slightly higher among hypertensive patients with diabetes and varied between 90.1 and 90.6 percent from 2007 to 2009.

Percentages of antihypertensive drug use among beneficiaries with hypertension varied by age, gender, race/ethnicity, and geographic region (Table 1 and Figures 1–3). For example, in 2009, 88.7 percent of female beneficiaries with hypertension and 85.3 percent of male beneficiaries with hypertension used an antihypertensive drug. Further, the northwestern and midwestern States were among the regions with the highest percentages of hypertensive patients who were dispensed an antihypertensive drug.

Figure 1

Yearly prevalence (%) of use of an antihypertensive drug in Medicare fee-for-service beneficiaries (Parts A, B, and D) with hypertension, 2007. White corresponds to areas that lack a hospital referral region (HRR)

Figure 2

Yearly prevalence (%) of use of an antihypertensive drug in Medicare fee-for-service beneficiaries (Parts A, B, and D) with hypertension, 2008. White corresponds to areas that lack a hospital referral region (HRR)

Figure 3

Yearly prevalence (%) of use of an antihypertensive drug in Medicare fee-for-service beneficiaries (Parts A, B, and D) with hypertension, 2009. White corresponds to areas that lack a hospital referral region (HRR)

In total, 142.4 million prescriptions for antihypertensive agents were dispensed to 10.4 million beneficiaries with hypertension in 2007. The total number of antihypertensive prescriptions dispensed decreased to 141.8 million in 2009, while the total number of beneficiaries increased to almost 11 million. The average annual number of antihypertensive drugs dispensed to a beneficiary with hypertension decreased from 13.7 to 12.8 prescriptions per individual during this period.

Hypertensive patients with diabetes received on average 14.8 prescriptions per individual in 2009. Beneficiaries with hypertension used on average 1.9 ± 1.3 antihypertensive drug classes within a calendar year (Table 1). However, patients age 75 and above, females, and black patients used on average two or more antihypertensive drug classes during a calendar year.

The top three dispensed antihypertensive classes were BBs, diuretics, and ACEIs from 2007 to 2009 (Figure 4). While the number of prescriptions dispensed by antihypertensive drug classes varied little between 2007 and 2009, the use of these different classes varied widely by geographic distribution. For example, ACEIs and diuretics were more commonly dispensed in northern States compared with southern States. In contrast, combination products were less commonly dispensed in northern states compared to southern states. Maps of the use of antihypertensive drug classes can be found online.

Figure 4

Total number of antihypertensive prescriptions dispensed to Medicare beneficiaries with hypertension by antihypertensive drug class, 2007 to 2009. * RAS = renin-angiotensin system.

Cost of Antihypertensive Drugs Among Those With Hypertension

Total drug cost and total out-of-pocket expense were calculated within the Medicare Part D Prescription Drug Event (PDE) file. The PDE file contains summary records of drug dispensing information from prescription plan sponsors. In 2009, the total drug cost for antihypertensive drugs was $4.3 billion. The average drug cost per Medicare beneficiary with hypertension was $393. Figure 5 shows the trend of drug cost by antihypertensive drug classes over the study period. The total reimbursement cost of ACEIs, BBs, and CCBs decreased from 2007 to 2009, while the costs of ARBs and combined products increased during this period.

Figure 5

Total cost of antihypertensive prescriptions dispensed to Medicare beneficiaries with hypertension, by antihypertensive drug class, 2007 to 2009. * RAS = renin-angiotensin system.

Total out-of-pocket expense for antihypertensive agents in 2009 was $2.2 billion, which was more than half of the total drug costs. The average out-of-pocket expense per Medicare beneficiary with hypertension was $195 in 2009. Figure 6 shows the trend of out-of-pocket expense by antihypertensive drug class over the study period. Similar trends were observed for total antihypertensive drug costs.

Figure 6

Total out-of-pocket expenditure of antihypertensive prescriptions dispensed to Medicare beneficiaries with hypertension, by antihypertensive drug class, 2007 to 2009. * RAS = renin-angiotensin system.

Eligible Population

Definition of Hypertension: Individuals were determined to have hypertension if they had one or more claims with International Classification of Diseases, 9th revision (ICD-9) codes consistent with hypertension (362.11, 401.x–405.x, 437.2, 997.91) during a calendar year.

Identification of Antihypertensive Drugs and Classes: Oral prescriptions of antihypertensive drugs (see Table 2) were identified using National Drug Codes.

Table 2

Antihypertensive drugs examined in this brief.

Definition of Antihypertensive Drug Users Among Beneficiaries With Hypertension: Beneficiaries with hypertension were classified as an antihypertensive drug user if they had a claim for one or more antihypertensive drug(s) during a calendar year.

Definition of Diabetes Among Beneficiaries With Hypertension: Beneficiaries with hypertension were determined to have diabetes if they had one or more claims with ICD-9 codes consistent with diabetes (250.00-03, 250.10-13, 250.20-23, 250.30-33, 250.40-43, 250.50-53, 250.60-63, 250.70-73, 250.80-83, 250.90-93) during a calendar year.

Calculation of Payments for Antihypertensive Drugs: For each of the study years of interest, we used Part D claims to calculate drug payment for antihypertensive drugs among beneficiaries with hypertension. The annual total drug cost was calculated as the sum of the ingredient cost, dispensing fee, sales tax, and vaccine administration fee (which only became effective in 2008) across all antihypertensive drug claims of interest (defined above). In addition, we calculated the total beneficiary out-of-pocket expense as the sum of patient pay, true out-of-pocket amount, and the low-income subsidy amount across all antihypertensive drug claims.

Generation of Maps: Maps were generated using Dartmouth Atlas of Health Care (www.dartmouthatlas.org) hospital referral regions (HRRs). Beneficiary Zip Codes of residence, as of December 31st of the given year, were extracted from the EDB and linked to HRRs. The percentages of beneficiaries with hypertension with use of antihypertensive drugs were grouped into quartiles and mapped accordingly. Geographic regions that did not correspond to an HRR were mapped in white. Regions with fewer than 11 beneficiaries contributing to the proportions presented were mapped in gray.