BackgroundAntihypertension medication (antihypertensive) adherence lowers risk of cardiovascular disease (CVD); few studies have examined this association among older adults.Methods and ResultsWe assessed this association among Medicare fee‐for‐service beneficiaries aged 66 to 79 years who were newly diagnosed with hypertension and initiated on antihypertensives in 2008–2009 (n=155 597). We calculated proportion of days covered (PDC) during follow‐up, using proportional subdistribution hazard models, to examine association between antihypertensive adherence and a composite CVD outcomes, including first incident of fatal/nonfatal acute myocardial infarction, ischemic heart disease, stroke/transient ischemic attack, and heart failure. During follow‐up (median 5.8 years and 798 621 person‐years), we documented 47 198 CVD events. Among beneficiaries, 60.8%, 30.3%, and 8.9% had PDC ≥80%, 40% to 79%, and <40%. Crude incidence of CVD events were 40.1 (95% CI, 40.0–40.1), 93.9 (93.8–93.9), and 98.1 (98.1–98.2) per 1000 person‐years for PDC ≥80%, 40% to 79%, and <40%, respectively. Adjusted hazard ratios for CVD events were 1.0 (<40% as reference), 1.0 (0.97–1.03) for 40% to 79%, and 0.44 (0.42–0.45) for ≥80% (P<0.001). Dose‐response analysis suggested a nonlinear relationship between PDC and risk for CVD events with a protective effect of ≥80%. The pattern of associations between PDC and ischemic heart disease, stroke/transient ischemic attack, and heart failure were largely consistent as for CVD events and across different groups.ConclusionsAntihypertensive adherence was associated with a significantly lower risk of CVD events among older adults. There appeared to be a threshold effect in reducing CVD events at around PDC 80%, above which the risk for CVD reduced substantially.

The enrollment (28.6%), engagement (mean number of visits = 25), and program completion rates (27.6%) remain low among Medicare beneficiaries in the United States, indicating that many patients did not fully benefit from a class I guideline-recommended therapy. Additional research and successful enrollment and engagement initiatives are needed, especially among identified populations.

Despite the importance of antihypertensive medication therapy for blood pressure control, no single data system provides estimates of medication nonadherence rates across age groups and health insurance plans types. Using multiple administrative datasets and national survey data, we determined health insurance plan-specific and overall weighted national rates of nonadherence to antihypertensive medications among insured hypertensive US adults in 2015. We used 2015 prescription claims data from Medicare Part D and 3 IBM MarketScan databases (Commercial, Medicaid, Medicare Supplemental) to calculate medication nonadherence rates among hypertensive adults aged ≥18 years with public or private health insurance using the proportion of days covered algorithm. These findings, in combination with National Health Interview Survey findings, were used to project national weighted estimates of nonadherence. We included 23.8 million hypertensive adults who filled 265.8 million prescriptions for antihypertensive medications. Nonadherence differed by health insurance plan type (highest for Medicaid members, 55.4%; lowest for Medicare Part D members, 25.2%). The overall weighted national nonadherence rate was 31.0%, with greater nonadherence among women versus men, younger versus older adults (aged 18–34 years, 58.1%; aged 65–74 years, 24.4%), fixed-dose combination medication nonusers (31.2%) versus users (29.4%), and by pharmacy outlet type (retail only, 30.7%; any mail order, 19.8%). In 2015, almost one-third (≈16.3 million) of insured US adults with diagnosed hypertension were considered nonadherent to their antihypertensive medication regimen, and considerable disparities were evident. Public health and healthcare professionals can use available evidence-based interventions to address nonadherence and improve blood pressure control.

Introduction: Nonadherence to taking prescribed antihypertensive medication (antihypertensive) regimens has been identified as a leading cause of poor blood pressure control among persons with hypertension and an important risk factor for adverse cardiovascular disease outcomes. CDC and the Centers for Medicare and Medicaid Services analyzed geographic, racial-ethnic, and other disparities in nonadherence to antihypertensives among Medicare Part D beneficiaries in 2014. Methods: Antihypertensive nonadherence, defined as a proportion of days a beneficiary was covered with antihypertensives of <80%, was assessed using prescription drug claims data among Medicare Advantage or Medicare fee-for-service beneficiaries aged ≥65 years with Medicare Part D coverage during 2014 (N = 18.5 million). Analyses were stratified by antihypertensive class, beneficiaries' state and county of residence, type of prescription drug plan, and treatment and demographic characteristics. Conclusions and Implications for Public Health Practice: More than one in four Medicare Part D beneficiaries using antihypertensives were nonadherent to their regimen, and certain racial/ethnic groups, states, and geographic areas were at increased risk for nonadherence. These findings can help inform focused interventions among these groups, which might improve blood pressure control and cardiovascular disease outcomes.

Background and ObjectivesFindings of association between coronavirus disease 2019 (COVID-19) and stroke remain inconsistent, ranging from significant association to absence of association to less than expected ischemic stroke among hospitalized patients with COVID-19. The current study examined the association between COVID-19 and risk of acute ischemic stroke (AIS).MethodsWe included 37,379 Medicare fee-for-service (FFS) beneficiaries aged ≥65 years diagnosed with COVID-19 from April 1, 2020, through February 28, 2021, and AIS hospitalization from January 1, 2019, through February 28, 2021. We used a self-controlled case series design to examine the association between COVID-19 and AIS and estimated the incidence rate ratios (IRRs) by comparing incidence of AIS in risk periods (0–3, 4–7, 8–14, 15–28 days after diagnosis of COVID-19) vs control periods.ResultsAmong 37,379 Medicare FFS beneficiaries with COVID-19 and AIS, the median age at diagnosis of COVID-19 was 80.4 (interquartile range 73.5–87.1) years and 56.7% were women. When AIS at day of exposure (day = 0) was included in the risk periods, IRRs at 0–3, 4–7, 8–14, and 15–28 days following COVID-19 diagnosis were 10.3 (95% confidence interval 9.86–10.8), 1.61 (1.44–1.80), 1.44 (1.32–1.57), and 1.09 (1.02–1.18); when AIS at day 0 was excluded in the risk periods, the corresponding IRRs were 1.77 (1.57–2.01) (day 1–3), 1.60 (1.43–1.79), 1.43 (1.31–1.56), and 1.09 (1.01–1.17), respectively. The association appeared to be stronger among younger beneficiaries and among beneficiaries without prior history of stroke but largely consistent across sex and race/ethnicities.DiscussionRisk of AIS among Medicare FFS beneficiaries was 10 times (day 0 cases in the risk period) as high during the first 3 days after diagnosis of COVID-19 as during the control period and the risk associated with COVID-19 appeared to be stronger among those aged 65–74 years and those without prior history of stroke.Classification of EvidenceThis study provides Class IV evidence that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with increased risk of AIS in the first 3 days after diagnosis in Medicare FFS beneficiaries ≥65 years of age.

Objective:To determine whether increased risk of acute ischemic stroke (AIS) following herpes zoster (HZ) might be modified by the status of Zoster Vaccine Live (ZVL) vaccination and antiviral treatment following HZ.Methods:We included 87,405 Medicare fee-for-service beneficiaries aged ≥66 years diagnosed with HZ and AIS from 2008-2017. We used a self-controlled case series design to examine the association between HZ and AIS, and estimated incident rate ratios (IRR) by comparing incidence of AIS in risk periods vs. control periods. To examine effect modification by ZVL and antiviral treatment, beneficiaries were classified into four mutually exclusive groups: (1) no vaccination and no antiviral treatment; (2) vaccination only; (3) antiviral treatment only; and (4) both vaccination and antiviral treatment. We tested for interaction to examine changes in IRRs across 4-groups.Results:Among 87,405 beneficiaries with HZ and AIS, 22.0%, 2.0%, 70.1% and 5.8% were in groups 1 to 4, respectively. IRRs in 0-14, 15-30, 31-90, and 91-180 days following HZ were 1.89 (95% confidence interval [CI],1.77-2.02), 1.58 (95% CI,1.47-1.69), 1.36 (95% CI,1.31-1.42), and 1.19 (95% CI,1.15-1.23), respectively. There was no evidence of effect modification by ZVL and antiviral treatment on AIS (p=0.067 for interaction). The pattern of association between HZ and risk for AIS was largely consistent across age group, sex, and race.Conclusions:Risk of AIS increased significantly following HZ, and this increased risk was not modified by ZVL and antiviral treatment. Our findings suggest the importance of following recommended HZ vaccination in prevention of HZ and HZ-associated AIS.

Objective To evaluate whether enrollment in deductible health plans (DHP), with higher patient cost-sharing requirements than traditional HMO plans (HMP), decreased initiation and completion of the HPV vaccine series, recommended for prevention of cervical cancer. Methods This was a retrospective observational study of 9-26 year old females at Kaiser Permanente Georgia (KPGA) and Kaiser Permanente Colorado (KPCO) who were HPV vaccine naïve at time of enrollment in a self-pay DHP or HMP in 2007. Estimates of rates of initiation and completion of the HPV vaccine series from plan enrollment in 2007 through 12/2009 were obtained using Cox proportional hazards (CPH) regressions (accounting for censoring) on samples matched on the propensity to enroll in a DHP vs. HMP. Results Initiation of the HPV vaccine series was 22.2% and 24.4% in the DHP and HMP, respectively, at KPGA; and, completion was 12.3% and 14.4% in the DHP and HMP, respectively. HPV vaccine series initiation was higher at KPCO; but, completion was lower. In the CPH regressions, rates of initiation and completion of the HPV vaccine series did not significantly (p≤0.05) differ by plan type (DHP vs. HMP) at both sites. The primary care visit rate included in these regressions had a significant, positive association with initiation and completion of the HPV vaccine series. Conclusions Enrollment in a DHP vs. HMP did not directly affect initiation or completion of the HPV vaccine series among age-eligible females. Independent of plan type, more frequent primary care visits increased initiation and completion rates.

Background and Purpose: Herpes zoster (HZ) is associated with increased risk of stroke, and zoster vaccine live (ZVL, Zostavax) reduces the risk of HZ. No study has examined the association between ZVL (Zostavax) and risk of stroke. Present study examined association between receipt of ZVL (Zostavax) and risk of stroke among older US population. Methods: Our study included 1 603 406 US Medicare fee-for-service beneficiaries aged ≥66 years without a history of stroke and who received ZVL (Zostavax) during 2008 to 2014, and 1 603 406 propensity score-matched unvaccinated beneficiaries followed through to December 31, 2017. We used Cox proportional hazard models to examine association between ZVL (Zostavax) and composite fatal or nonfatal incident stroke outcomes. Results: During a median of 5.1 years follow-up (interquartile range, 3.9–6.7), we documented 64 635 stroke events, including 43 954 acute ischemic strokes and 6727 hemorrhagic strokes, among vaccinated beneficiaries during 8 755 331 person-years. The corresponding numbers among unvaccinated beneficiaries were 73 023, 50 476, and 7276, respectively, during 8 517 322 person-years. Incidence comparing vaccinated to unvaccinated beneficiaries were 7.38 versus 8.57 per 1000 person-years for all stroke, 5.00 versus 5.90 for acute ischemic stroke, and 0.76 versus 0.84 for hemorrhagic stroke ( P <0.001 for all difference). Adjusted hazard ratios comparing vaccinated to unvaccinated beneficiaries were 0.84 (95% CI, 0.83–0.85), 0.83 (0.82–0.84), and 0.88 (0.85–0.91) for all stroke, acute ischemic stroke, and hemorrhagic stroke, respectively. The association between ZVL (Zostavax) and risk of stroke appeared to be stronger among younger beneficiaries, beneficiaries who did not take antihypertensive or statin medications and who had fewer comorbid conditions ( P <0.05 for interaction) but largely consistent across sex, low-income status, and racial groups. Conclusions: Among Medicare fee-for-service beneficiaries, receipt of ZVL (Zostavax) was associated with lower incidence of stroke. Our findings may encourage people to get vaccinated against HZ to reduce HZ and HZ-associated stroke risk.