Geographic Disparities in the Incidence of Stroke among Patients with Atrial Fibrillation in the United States

Geographic variation in clinical outcomes and anticoagulation among medicare beneficiaries with non-valvular atrial fibrillation

Oral anticoagulants (OACs) have been used to prevent stroke/systemic embolism (SE) among patients with non-valvular atrial fibrillation (NVAF). To evaluate baseline clinical characteristics, incidence rates of stroke/SE and hospitalization for bleeding, and OAC use among elderly patients with NVAF in the US by geographic region. Patients with NVAF were selected from the US Centers for Medicare & Medicaid Services claims database (01JAN2013-31DEC2016). Twelve months of health plan enrollment was required before and after the NVAF diagnosis to evaluate baseline characteristics and outcomes, respectively. Each patient was assigned to a 3-digit zip code based on their primary residence, and geographic variation was visualized using ArcGIS Pro software. Over 2.8 million patients with NVAF were identified. Large geographic variation was observed in clinical characteristics, stroke/SE, hospitalization for bleeding, and OAC use among patients across the US. The zip codes with the highest mean CHA2DS2-VASc scores and frequency of prior bleeding also had the highest incidence of stroke/SE and hospitalization for bleeding. Across 3-digit zip codes, 35-63% of patients were untreated. Overall, the incidence of stroke/SE and hospitalization for bleeding were higher and OAC treatment was less frequent in zip codes located in the Southern US. Baseline clinical characteristics, incidence rates of stroke/SE and hospitalization for bleeding, and OAC usage vary considerably by 3-digit zip code in the US. The additional granularity provided in this study may help clinicians to identify small regions with high-risk of stroke/SE and hospitalization for bleeding and low use of OAC that may benefit from targeted care strategies.

Sociodemographic and geographic differences in the US epidemiology of autoimmune hepatitis with and without cirrhosis

BACKGROUND AND AIMS

Data on the epidemiology of autoimmune hepatitis (AIH) in the United States are limited. This study investigated the sociodemographic and geographic factors associated with AIH incidence and prevalence with and without cirrhosis.

APPROACH AND RESULTS

In a retrospective cohort of adults in the Optum Clinformatics Data Mart (2009-2018), we identified AIH cases using a validated claims-based algorithm. Incidence and prevalence were compared between sociodemographic subgroups. Logistic regression evaluated the association of US Census Division with AIH incidence and the factors associated with incident AIH with cirrhosis. From 2009 to 2018, the age- and sex-standardized prevalence of AIH in the Optum cohort was 26.6 per 100,000 persons with an incidence of 4.0 per 100,000 person-years. AIH incidence increased earlier among Hispanics (age 50-59 years) and later among Asians (≥80 years). Adjusted AIH incidence was higher in the Mountain Division (odds ratio [OR] 1.17) and lower in the Pacific (OR 0.68), Middle Atlantic (OR 0.81), and West North Central Divisions (OR 0.86 vs. East North Central; p < 0.001). Male sex (OR 1.31, p = 0.003), Black race (OR 1.32, p = 0.022), and Hispanic ethnicity (OR 1.37 vs. non-Hispanic White, p = 0.009) were associated with incident AIH with cirrhosis. Incident AIH with cirrhosis was greater in the West South Central Division (OR 1.30 vs. South Atlantic; p = 0.008).

CONCLUSIONS

AIH epidemiology differs according to sociodemographic and geographic factors in the United States. Studies are needed to determine the genetic, epigenetic, and environmental factors underlying the heterogeneity in AIH risk and outcomes.

Risk Levels and Adverse Clinical Outcomes Among Patients With Nonvalvular Atrial Fibrillation Receiving Oral Anticoagulants

IMPORTANCE

The CHA2DS2-VASc score (calculated as congestive heart failure, hypertension, age 75 years and older, diabetes, stroke or TIA, vascular disease, age 65 to 74 years, and sex category) is the standard for assessing risk of stroke and systemic embolism and includes age and thromboembolic history. To our knowledge, no studies have comprehensively evaluated safety and effectiveness outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants according to independent, categorical risk strata.

OBJECTIVE

To evaluate the incidence of key adverse outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants by CHA2DS2-VASc risk score range, thromboembolic event history, and age group.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was a retrospective claims data analysis using combined data sets from 5 large health claims databases. Eligible participants were adult patients with nonvalvular atrial fibrillation who initiated oral anticoagulants. Data were analyzed between January 2012 and June 2019.

EXPOSURE

Initiation of oral anticoagulants.

MAIN OUTCOMES AND MEASURES

We observed clinical outcomes (including stroke or systemic embolism, major bleeding, and a composite outcome) on treatment through study end, censoring for discontinuation of oral anticoagulants, death, and insurance disenrollment. The population was stratified by CHA2DS2-VASc risk score; history of stroke, systemic embolism, or transient ischemic attack; and age groups. We calculated time to event, incidence rates, and cumulative incidence for outcomes.

RESULTS

We identified 1 141 097 patients with nonvalvular atrial fibrillation; the mean (SD) age was 75.0 (10.5) years, 608 127 patients (53.3%) were men, and over 1 million were placed in the 2 highest risk categories (high risk 1, 327 766 participants; high risk 2, 688 449 participants). Deyo-Charlson Comorbidity Index scores ranged progressively alongside CHA2DS2-VASc risk score strata (mean [SD] scores: low risk, 0.4 [1.0]; high risk 2, 4.1 [2.9]). The crude incidence of stroke and systemic embolism generally progressed alongside risk score strata (low risk, 0.25 events per 100 person-years [95% CI, 0.18-0.34 events]; high risk 2, 3.43 events per 100 person-years [95% CI, 3.06-4.20 events]); patients at the second-highest risk strata with thromboembolic event history had higher stroke incidence vs patients at the highest risk score strata without event history (2.06 events per 100 person-years [95% CI, 2.00-3.12 events] vs 1.18 events per 100 person-years [95% CI, 1.14-1.30 events]). Major bleeding and composite incidence also increased progressively alongside risk score strata (major bleeding: low risk, 0.68 events per 100 person-years [95% CI, 0.56-0.82 events]; high risk 2, 6.29 events per 100 person-years [95% CI, 6.21-6.62 events]; composite incidence: 1.22 events per 100 person-years [95% CI, 1.06-1.41 events]; high risk 2, 10.67 events per 100 person-years [95% CI, 10.26-11.48 events]). The 12-month cumulative incidence proportions for stroke and systemic embolism, major bleeding, and composite outcomes progressed alongside risk score strata (stroke or systemic embolism, 0.30%-1.85%; major bleeding, 0.55%-5.55%; composite, 1.05%-8.23%). Age subgroup analysis followed similar trends.

CONCLUSIONS AND RELEVANCE

The observed incidence of stroke or systemic embolism and major bleeding events generally conformed to an expected increasing incidence by risk score, adding insight into the importance of specific risk score range, thromboembolic event history, and age group strata. These results can help inform clinical decision-making, research, and policy.

Social Determinants of Stroke Hospitalization and Mortality in United States' Counties

(1) Background: Stroke incidence and outcomes are influenced by socioeconomic status. There is a paucity of reported population-level studies regarding these determinants. The goal of this ecological analysis was to determine the county-level associations of social determinants of stroke hospitalization and death rates in the United States. (2) Methods: Publicly available data as of 9 April 2021, for the socioeconomic factors and outcomes, was extracted from the Centers for Disease Control and Prevention. The outcomes of interest were “all stroke hospitalization rates per 1000 Medicare beneficiaries” (SHR) and “all stroke death rates per 100,000 population” (SDR). We used a multivariate binomial generalized linear mixed model after converting the outcomes to binary based on their median values. (3) Results: A total of 3226 counties/county-equivalents of the states and territories in the US were analyzed. Heart disease prevalence (odds ratio, OR = 2.03, p < 0.001), blood pressure medication nonadherence (OR = 2.02, p < 0.001), age-adjusted obesity (OR = 1.24, p = 0.006), presence of hospitals with neurological services (OR = 1.9, p < 0.001), and female head of household (OR = 1.32, p = 0.021) were associated with high SHR while cost of care per capita for Medicare patients with heart disease (OR = 0.5, p < 0.01) and presence of hospitals (OR = 0.69, p < 0.025) were associated with low SHR. Median household income (OR = 0.6, p < 0.001) and park access (OR = 0.84, p = 0.016) were associated with low SDR while no college degree (OR = 1.21, p = 0.049) was associated with high SDR. (4) Conclusions: Several socioeconomic factors (e.g., education, income, female head of household) were found to be associated with stroke outcomes. Additional research is needed to investigate intermediate and potentially modifiable factors that can serve as targeted interventions.

Racial and Ethnic Differences in the Management of Atrial Fibrillation

Atrial fibrillation (AF) is the most common clinical arrhythmia, and it results in adverse outcomes and increased healthcare costs. Racial and ethnic differences in AF management, although recognized, are poorly understood. This review summarizes racial differences in AF epidemiology, genetics, clinical presentation, and management. In addition, it highlights the underrepresentation of racial and ethnic populations in AF clinical trials, especially trials focused on stroke prevention. Specific strategies are proposed for future research and initiatives that have potential to eliminate racial and ethnic differences in the care of patients with AF. Addressing racial and ethnic disparities in healthcare access, enrollment in clinical trials, resource allocation, prevention, and management will likely narrow the gaps in the care and outcomes of racial and ethnic minorities suffering from AF.

Gender difference of geographic distribution of the stroke incidence affected by socioeconomic, clinical and urban-rural factors: an ecological study based on data from the Brest stroke registry in France

Background

Mapping the spatial distribution of disease occurrence is a strategy to identify contextual factors that could be useful for public health policies. The purpose of this ecological study was to examine to which extent the socioeconomic deprivation and the urbanization level can explain gender difference of geographic distribution in stroke incidence in Pays de Brest, France between 2008 and 2013.

Methods

Stroke cases aged 60 years or more were extracted from the Brest stroke registry and combined at the census block level. Contextual socioeconomic, demographic, and geographic variables at the census block level come from the 2013 national census. We used spatial and non-spatial regression models to study the geographic correlation between socioeconomic deprivation, degree or urbanization and stroke incidence. We generated maps using spatial geographically weighted models, after longitude and latitude smoothing and adjustment for covariates.

Results

Stroke incidence was comparable in women and men (6.26 ± 3.5 vs 6.91 ± 3.3 per 1000 inhabitants-year, respectively). Results showed different patterns of the distribution of stroke risk and its association with deprivation or urbanisation across gender. For women, stroke incidence was spatially homogeneous over the entire study area, but was associated with deprivation level in urban census blocks: age adjusted risk ratio of high versus low deprivation = 1.24, [95%CI 1.04–1.46]. For men, three geographic clusters were identified. One located in the northern rural and deprived census blocks with a 9–14% increase in the risk of stroke. Two others clusters located in the south-eastern (mostly urban part) and south-western (suburban and rural part) with low deprivation level and associated with higher risk of stroke incidence between (3 and 8%) and (8.5 and 19%) respectively. There were no differences in profile of cardiovascular risk factors, stroke type and stroke severity between clusters, or when comparing clusters cases to the rest of the study population.

Conclusions

Understanding whether and how neighborhood and patient’s characteristics influence stroke risk may be useful for both epidemiological research and healthcare service planning.

An Atrial Fibrillation Transitions of Care Clinic Improves Atrial Fibrillation Quality Metrics

OBJECTIVES

This study sought to assess whether an atrial fibrillation (AF)-specific clinic is associated with improved adherence to American College of Cardiology (ACC)/American Heart Association (AHA) clinical performance and quality measures for adults with AF or atrial flutter.

BACKGROUND

There are significant gaps in care of patients with AF, including underprescription of anticoagulation and treatment of AF risk factors. An AF specialized clinic was developed to reduce admissions for AF but may also be associated with improved quality of care.

METHODS

This retrospective study compared adherence to ACC/AHA measures for patients who presented to the emergency department for AF between those discharged to a typical outpatient appointment and those discharged to a specialized AF transitions clinic run by an advanced practice provider and supervised by a cardiologist. Screening and treatment for common AF risk factors was also assessed.

RESULTS

The study enrolled 78 patients into the control group and 160 patients into the intervention group. Patients referred to the specialized clinic were more likely to have stroke risk assessed and documented (99% vs. 26%; p < 0.01); be prescribed appropriate anticoagulation (97% vs. 88%; p = 0.03); and be screened for comorbidities such as tobacco use (100% vs. 14%; p < 0.01), alcohol use (92% vs. 60%; p < 0.01), and obstructive sleep apnea (90% vs. 13%; p < 0.01) and less likely to be prescribed an inappropriate combination of anticoagulant and antiplatelet medications (1% vs. 9%; p < 0.01).

CONCLUSIONS

An AF specialized clinic was associated with improved adherence to ACC/AHA clinical performance and quality measures for adult patients with AF.

Comparative Incidence of Inflammatory Bowel Disease in Different Age Groups in the United States

BACKGROUND

Data on the incidence of inflammatory bowel disease (IBD) by age group are available in countries outside of the United States or localized populations within the United States. We aimed to estimate the incidence rates (IRs) of IBD by age group using a US multiregional data set.

METHODS

We used the Optum Research Database to identify incident IBD patients with a disease-free interval of 1.5 years between 2005 and 2015. Overall and age-specific IRs were calculated for 4 different age groups: pediatric (0-17 years), young adult (18-25 years), adult (26-59 years), elderly (>60 years). Time trends of incidence were evaluated in each age group. Perianal phenotype (in Crohn's disease [CD]) was also compared.

RESULTS

The mean IR for the cohort (n = 60,247) from 2005 to 2015 was 37.5/100,000. The IR was highest in adult and elderly cohorts (36.4 and 36.7/100,000 respectively). In the adult and elderly groups, the IR for UC was higher than that for CD, whereas the opposite was true in the pediatric and young adult groups. The IR increased over the 10-year study period for all age groups (time trends P < 0.001). The elderly group had less perianal disease than the adult group (20.8 vs 22.3%, respectively; P < 0.05).

CONCLUSIONS

In one of the most comprehensive evaluations of the incidence of IBD in the United States, we found an incidence rate similar to those of other national populations. We also confirmed differences of specific IBD phenotypes based on age groups, with lower rates of perianal disease in the elderly.

Atrial Fibrillation in Middle Eastern Arabs and South Asians: Summary of Published Articles in the Arabian Gulf

Seven studies are summarized herein focusing on different aspects of Atrial fibrillation (AF) in two unique ethnicities for which there is very limited literature published before; Middle Eastern Arabs and South Asians, using data from a national registry of cardiovascular diseases in Qatar over a 20-years period (1991-2010). These studies shed light upon important aspects of AF presentations and outcomes in these two ethnicities, thereby enriching the world literature on AF. In the process, several novel observations were reported and new questions were raised that warrant further investigations.

HIV Infection and Incidence of Cardiovascular Diseases: An Analysis of a Large Healthcare Database

Background

People living with HIV (PLWH) experience higher risk of myocardial infarction (MI) and heart failure (HF) compared with uninfected individuals. Risk of other cardiovascular diseases (CVDs) in PLWH has received less attention.

Methods and Results

We studied 19 798 PLWH and 59 302 age‐ and sex‐matched uninfected individuals identified from the MarketScan Commercial and Medicare databases in the period 2009 to 2015. Incidence of CVDs, including MI, HF, atrial fibrillation, peripheral artery disease, stroke and any CVD‐related hospitalization, were identified using validated algorithms. We used adjusted Cox models to estimate hazard ratios and 95% CIs of CVD end points and performed probabilistic bias analysis to control for unmeasured confounding by race. After a mean follow‐up of 20 months, patients experienced 154 MIs, 223 HF, 93 stroke, 397 atrial fibrillation, 98 peripheral artery disease, and 935 CVD hospitalizations (rates per 1000 person‐years: 1.2, 1.7, 0.7, 3.0, 0.8, and 7.1, respectively). Hazard ratios (95% CI) comparing PLWH with uninfected controls were 1.3 (0.9–1.9) for MI, 3.2 (2.4–4.2) for HF, 2.7 (1.7–4.0) for stroke, 1.2 (1.0–1.5) for atrial fibrillation, 1.1 (0.7–1.7) for peripheral artery disease, and 1.7 (1.5–2.0) for any CVD hospitalization. Adjustment for unmeasured confounding led to similar associations (1.2 [0.8–1.8] for MI, 2.8 [2.0–3.8] for HF, 2.3 [1.5–3.6] for stroke, 1.3 [1.0–1.7] for atrial fibrillation, 0.9 [0.5–1.4] for peripheral artery disease, and 1.6 [1.3–1.9] for CVD hospitalization).

Conclusions

In a large health insurance database, PLWH have an elevated risk of CVD, particularly HF and stroke. With the aging of the HIV population, developing interventions for cardiovascular health promotion and CVD prevention is imperative.