Linkage of a Population-Based Cohort With Primary Data Collection to Medicare Claims: The Reasons for Geographic and Racial Differences in Stroke Study

Population-average mediation analysis for zero-inflated count outcomes

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations.

Ambulatory Care Fragmentation and Total Health Care Costs

BACKGROUND

The magnitude of the relationship between ambulatory care fragmentation and subsequent total health care costs is unclear.

OBJECTIVE

To determine the association between ambulatory care fragmentation and total health care costs.

RESEARCH DESIGN

Longitudinal analysis of 15 years of data (2004-2018) from the national Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, linked to Medicare fee-for-service claims.

SUBJECTS

A total of 13,680 Medicare beneficiaries who are 65 years and older.

MEASURES

We measured ambulatory care fragmentation in each calendar year, defining high fragmentation as a reversed Bice-Boxerman Index ≥0.85 and low as <0.85. We used generalized linear models to determine the association between ambulatory care fragmentation in 1 year and total Medicare expenditures (costs) in the following year, adjusting for baseline demographic and clinical characteristics, a time-varying comorbidity index, and accounting for geographic variation in reimbursement and inflation.

RESULTS

The average participant was 70.9 years old; approximately half (53%) were women. One-fourth (26%) of participants had high fragmentation in the first year of observation. Those participants had a median of 9 visits to 6 providers, with the most frequently seen provider accounting for 29% of visits. By contrast, participants with low fragmentation had a median of 8 visits to 3 providers, with the most frequently seen provider accounting for 50% of visits. High fragmentation was associated with $1085 more in total adjusted costs per person per year (95% CI $713 to $1457) than low fragmentation.

CONCLUSIONS

Highly fragmented ambulatory care in 1 year is independently associated with higher total costs the following year.

Ambulatory Care Fragmentation, Emergency Department Visits, and Race: a Nationwide Cohort Study in the U.S

BACKGROUND

It is unclear whether highly fragmented ambulatory care (i.e., care spread across multiple providers without a dominant provider) increases the risk of an emergency department (ED) visit. Whether any such association varies with race is unknown.

OBJECTIVE

We sought to determine whether highly fragmented ambulatory care increases the risk of an ED visit, overall and by race.

DESIGN AND PARTICIPANTS

We analyzed data for 14,361 participants ≥ 65 years old from the nationwide prospective REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort study, linked to Medicare claims (2003-2016).

MAIN MEASURES

We defined high fragmentation as a reversed Bice-Boxerman Index ≥ 0.85 (≥ 75th percentile). We used Poisson models to determine the association between fragmentation (as a time-varying exposure) and ED visits, overall and stratified by race, adjusting for demographics, medical conditions, medications, health behaviors, psychosocial variables, and physiologic variables.

KEY RESULTS

The average participant was 70.5 years old; 53% were female, and 33% were Black individuals. Participants with high fragmentation had a median of 9 visits to 6 providers, with 29% of visits by the most frequently seen provider; participants with low fragmentation had a median of 7 visits to 3 providers, with 50% of visits by the most frequently seen provider. Overall, high fragmentation was associated with more ED visits than low fragmentation (adjusted risk ratio [aRR] 1.31, 95% confidence interval [CI] 1.29, 1.34). The magnitude of this association was larger among Black (aRR 1.48, 95% CI 1.44, 1.53) than White participants (aRR 1.23, 95% CI 1.20, 1.25).

CONCLUSIONS

Highly fragmented ambulatory care was an independent predictor of ED visits, especially among Black individuals.

Depressive symptoms, cognitive impairment, and all-cause mortality among REGARDS participants with heart failure

Aims

To ascertain whether depressive symptoms and cognitive impairment (CI) are associated with mortality among patients with heart failure (HF), adjusting for sociodemographic, comorbidities, and biomarkers.

Methods and results

We utilized Medicare-linked data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, a biracial prospective ongoing cohort of 30 239 US community-dwelling adults, recruited in 2003-07. HF diagnosis was ascertained in claims analysis. Depressive symptoms were defined as a score ≥4 on the four-item Center for Epidemiological Studies-Depression scale. Cognitive impairment was defined as a score of ≤4 on the six-item screener that assessed three-item recall and orientation to year, month, and day of the week. Sequentially adjusted Cox proportional hazard models were used to estimate the risk of death. We analyzed 1059 REGARDS participants (mean age 73, 48%-African American) with HF; of those 146 (14%) reported depressive symptoms, 136 (13%) had CI and 31 (3%) had both. Over the median follow-up of 6.8 years (interquartile range, 3.4-10.3), 785 (74%) died. In the socio-demographics-adjusted model, CI was significantly associated with increased mortality, hazard ratio 1.24 (95% confidence interval 1.01-1.52), compared with persons with neither depressive symptoms nor CI, but this association was attenuated after further adjustment. Neither depressive symptoms alone nor their comorbidity with CI was associated with mortality. Risk factors of all-cause mortality included: low income, comorbidities, smoking, physical inactivity, and severity of HF.

Conclusion

Depressive symptoms, CI, or their comorbidity was not associated with mortality in HF in this study. Treatment of HF in elderly needs to be tailored to cognitive status and includes focus on medical comorbidities.

Nearly All Cancer Survivors Return to Primary Care

BACKGROUND

During cancer treatments, patients often defer primary care and comorbidity management, which may not be optimal for overall health when patients transition into survivorship. We sought to quantify primary care utilization among cancer survivors who are ≥2 years post cancer treatments.

METHODS

951 cancer survivors were included in this national, prospective cohort study using the Regional Geographic and Racial Differences in Stroke (REGARDS) data.

RESULTS

Nearly all (91.6%) cancer survivors had at least 1 annual PCP visit and most (54.6%) had a PCP as their dominant provider.

CONCLUSION

These findings underscore the urgent need for smooth handoffs from oncology back to primary care.

Completeness of cohort-linked U.S. Medicare data: An example from the Agricultural Health Study (1999–2016)

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We describe linked U.S. Medicare claims data in the Agricultural Health Study.

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Incomplete claims data were related to geographic, demographic, and health.

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We saw potential informative missingness by pesticide use and mortality.

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Incomplete data in Medicare-linked cohorts may impact sample size and validity.

Medicare Fee for Service (FFS) claims data, including inpatient (Part A) and outpatient (Part B) services, provide a valuable resource for research on older adults (≥65 year) in linked U.S. cohorts. Here we describe our experience linking the Agricultural Health Study cohort, including 47,501 licensed pesticide applicators and spouses from North Carolina (NC) and Iowa (IA) to Medicare claims data from 1999 to 2016. Given increased Part C (i.e., managed care/Medicare Advantage) enrollment during this period, and a resulting lack of available Part C claims data prior to 2015, we also explored potential for informative missingness. We compared those with partial or limited/no FFS to those with complete FFS coverage (i.e., ≥11 months per year parts AB, but not C, throughout Medicare enrollment) in relation to baseline farm size, general pesticide use, and mortality, in logistic regression models adjusted for age, sex, race, education, and smoking, and stratified by state. While 46,689 participants (98%) were linked to Medicare IDs, only 33,487 (70%) had complete FFS, 9353 (20%) had partial FFS (≥1 year FFS but not complete), and 3849 (8%) had limited/no FFS (Part A or Part C-only). Incomplete FFS was more common in NC, mostly due to Part C, and was associated with farm characteristics, pesticide use, and mortality. These findings indicate that, in addition to reduced sample size in analyses limited to complete FFS, missingness may not be random. The potential impact of incomplete FFS data and changes in coverage type need to be considered when planning linked analyses and interpreting results.

Insomnia Diagnosis, Prescribed Hypnotic Medication Use, and Risk for Serious Fall Injuries in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

STUDY OBJECTIVES

Insomnia is common among older adults and associated with an increased risk for falls. Determining if falls are more strongly associated with insomnia or prescribed hypnotic medications could be used to guide interventions to reduce falls risk.

METHODS

We examined the prospective association of a diagnosis of insomnia and/or prescribed hypnotic medication use with the risk for serious fall injuries among 9087 Reasons for Geographic and Racial Differences in Stroke (REGARDS) study participants aged 65 years or older with Medicare fee-for-service health insurance at baseline (2003-2007). A diagnosis of insomnia was based on ICD-9 codes in Medicare claims and prescribed hypnotic medication use was determined through a pill bottle review. Serious fall injuries were identified by Medicare claims between baseline and December 31, 2018.

RESULTS

Over a median of 6.8 years, 1660 (18.3%) participants had a serious fall injury. The incidence rates for a serious fall injury per 1000 person-years were 24.8 (95%CI: 23.5, 26.1), 28.8 (95%CI: 18.6, 38.9), 32.6 (95%CI: 28.2, 37.0), and 46.6 (95%CI: 26.7, 66.5) for participants without insomnia or taking prescribed hypnotic medication (-insomnia/-hypnotics), with insomnia only (+insomnia/-hypnotics), taking prescribed hypnotic medication only (-insomnia/+hypnotics), and with insomnia and taking prescribed hypnotic medication (+insomnia/+hypnotics), respectively. Compared with the -insomnia/-hypnotic group, the multivariable-adjusted hazard ratios for a serious fall injury were 1.13 (95%CI: 0.79, 1.61), 1.29 (95%CI: 1.11, 1.50), and 1.60 (95%CI: 1.01, 2.56) for +insomnia/-hypnotics, -insomnia/+hypnotics, and +insomnia/+hypnotics, respectively.

CONCLUSIONS

The risk for serious fall injuries was higher for those taking prescribed hypnotic medications but not with an insomnia diagnosis.

Health care fragmentation and blood pressure control among adults taking antihypertensive medication

OBJECTIVES

To determine the association of fragmented ambulatory health care with uncontrolled blood pressure (BP) and apparent treatment-resistant hypertension (aTRH) among older adults taking antihypertensive medication, overall and by race and gender.

STUDY DESIGN

Cross-sectional study using data from 2868 REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants 66 years and older who completed a study examination in 2013-2016, had Medicare fee-for-service coverage, and were taking antihypertensive medication.

METHODS

We used logistic regression to analyze the association of fragmented health care with uncontrolled BP and aTRH. Fragmented health care was operationalized as a reversed Bice-Boxerman Index score in the 75th percentile or higher, calculated using the number of ambulatory providers and health care visits in the year preceding the study examination. Uncontrolled BP was defined by systolic BP of at least 140 mm Hg or diastolic BP of at least 90 mm Hg. aTRH was defined by taking 3 or more classes of antihypertensive medication with uncontrolled BP or 4 or more classes with controlled BP.

RESULTS

The overall adjusted odds ratios (95% CIs) for uncontrolled BP, aTRH with controlled BP, and aTRH with uncontrolled BP associated with fragmented health care were 1.10 (0.89-1.37), 1.08 (0.80-1.47), and 1.32 (0.96-1.81), respectively. Fragmented health care was not associated with uncontrolled BP or aTRH among White participants, women, or men. Among Black participants, the odds ratio (95% CI) associated with fragmented health care was 1.21 (0.81-1.82) for uncontrolled BP, 1.22 (0.72-2.07) for aTRH with controlled BP, and 1.82 (1.07-3.11) for aTRH with uncontrolled BP.

CONCLUSIONS

Fragmented health care may increase the likelihood of aTRH with uncontrolled BP among older Black adults taking antihypertensive medication.

Systematic Investigation of the Effect of Powerful Tianma Eucommia Capsule on Ischemic Stroke Using Network Pharmacology

Background

Ischemic stroke (IS) is a serious disease with a high rate of death and disability, and a growing number of people are becoming victims. Existing drugs not only have limited therapeutic effects but also have obvious side effects. Most importantly, drug resistance due to long-term or improper use of drugs is detrimental to patients. Therefore, it is urgent to find some alternative or supplementary medicines to alleviate the current embarrassment. Powerful Tianma Eucommia Capsule (PTEC) is mainly used to treat IS in China for thousands of years; however, the molecular mechanism is not clear.

Methods

Pharmacology ingredients and target genes were filtered and downloaded from websites. A pharmacology ingredient-target gene network was constructed to predict the molecular interactions between ingredients and target genes. Enrichment analysis was performed to explore the possible signal pathways. LeDock was used to simulate the interaction form between proteins and main active ingredients and to deduce key amino acid positions.

Results

Two hundred eighty-nine target genes and seventy-four pharmacological ingredients were obtained from public databases. Several key ingredients (quercetin, kaempferol, and stigmasterol) and primary core target genes (PTGS1, NCOA2, and PRSS1) were detected through ingredient-target gene network analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis demonstrated that ingredients affect networks mainly in nuclear receptor activity and G protein-coupled amine receptor activity; besides, fluid shear stress and atherosclerosis, human cytomegalovirus infection, and hepatitis B signaling pathways might be the principal therapy ways. A series of presumed key amino acid sites (189ASP, 190SER, 192GLN, 57HIS, and 99TYE) were calculated in PRSS1. Six of the target genes were differentially expressed between male and female patients.

Conclusions

Seven new putative target genes (ACHE, ADRA1A, AR, CHRM3, F7, GABRA1, and PRSS1) were observed in this work. Based on the result of GO and KEGG analysis, this work will be helpful to further demonstrate the molecular mechanism of PTEC treatment of IS.

Ambulatory Care Fragmentation and Incident Stroke

Background More fragmented ambulatory care (ie, care spread across many providers without a dominant provider) has been associated with excess emergency department and inpatient care. We sought to determine whether more fragmented ambulatory care is associated with an increase in the hazard of incident stroke, overall and stratified by health status and by race. Methods and Results We conducted a secondary analysis of data from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study (2003-2016), including participants aged ≥65 years who had linked Medicare fee-for-service claims and no history of stroke (N=12 510). We measured fragmentation of care with the reversed Bice-Boxerman index. We used Poisson models to determine the association between fragmentation and adjudicated incident stroke. The average age of participants was 70.5 years; 53% were women, 32% were Black participants, and 16% were participants with fair or poor health. Overall, the adjusted rate of incident stroke was similar for high versus low fragmentation (8.2 versus 8.1 per 1000 person-years, respectively; P=0.89). Among participants with fair or poor self-rated health, having high versus low fragmentation was associated with a trend toward a higher adjusted rate of incident strokes (14.8 versus 10.4 per 1000 person-years, respectively; P=0.067). Among Black participants with fair or poor self-rated health, having high versus low fragmentation was associated with a higher adjusted rate of strokes (19.3 versus 10.3 per 1000 person-years, respectively; P=0.02). Conclusions Highly fragmented ambulatory care is independently associated with incident stroke among Black individuals with fair or poor health.

Ambulatory Care Fragmentation and Subsequent Hospitalization: Evidence From the REGARDS Study

BACKGROUND

Previous studies have suggested that highly fragmented ambulatory care increases the risk of subsequent hospitalization, but those studies used claims only and were not able to adjust for many clinical potential confounders.

OBJECTIVE

The objective of this study was to determine the association between fragmented ambulatory care and subsequent hospitalization, adjusting for demographics, medical conditions, medications, health behaviors, psychosocial variables, and physiological variables.

DESIGN

Longitudinal analysis of data (2003-2016) from the nationwide REasons for Geographic And Racial Differences in Stroke (REGARDS) study, linked to Medicare fee-for-service claims.

SUBJECTS

A total of 12,693 Medicare beneficiaries 65 years and older from the REGARDS study who had at least 4 ambulatory visits in the first year of observation and did not have a hospitalization in the prior year.

MEASURES

We defined high fragmentation as a reversed Bice-Boxerman score above the 75th percentile. We used Cox proportional hazards models to determine the association between fragmentation as a time-varying exposure and incident hospitalization in the 3 months following each exposure period.

RESULTS

The mean age was 70.4 years; 54% were women, and 33% were African American. During the first year of observation, participants with high fragmentation had a median of 8 ambulatory visits with 6 providers, whereas participants with low fragmentation had a median of 7 visits with 3 providers. Over 11.8 years of follow-up, 6947 participants (55%) had a hospitalization. High fragmentation was associated with an increased hazard of hospitalization (adjusted hazard ratio=1.18; 95% confidence interval: 1.12, 1.24).

CONCLUSION

Highly fragmented ambulatory care is an independent risk factor for hospitalization.

Differences in ambulatory care fragmentation by race

BACKGROUND

More fragmented ambulatory care (i.e., care spread across many providers without a dominant provider) has been associated with more subsequent healthcare utilization (such as more tests, procedures, emergency department visits, and hospitalizations) than less fragmented ambulatory care. It is not known if race and socioeconomic status are associated with fragmented ambulatory care.

METHODS

We conducted a longitudinal analysis of data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, using the REGARDS baseline visit plus the first year of follow-up. We included participants ≥65 years old, who had linked fee-for-service Medicare claims, and ≥ 4 ambulatory visits in the first year of follow-up. We used Tobit regression to determine the associations between race, annual household income, and educational attainment at baseline and fragmentation score in the subsequent year (as measured with the reversed Bice-Boxerman Index). Covariates included other demographic characteristics, medical conditions, medication use, health behaviors, and psychosocial variables. Additional analyses categorized visits by the type of provider (primary care vs. specialist).

RESULTS

The study participants (N = 6799) had an average age of 73.0 years, 53% were female, and 30% were black. Nearly half had low annual household income (<$35,000) and 41% had a high school education or less. Overall, participants had a median of 10 ambulatory visits to 4 providers in the 12 months following their baseline study visit. Participants in the highest quintile of fragmentation scores had a median of 11 visits to 7 providers. Black race was associated with an absolute adjusted 3% lower fragmentation score compared to white race (95% confidence interval (2% lower to 4% lower; p < 0.001). This difference was explained by blacks seeing fewer specialists than whites. Income and education were not independent predictors of fragmentation scores.

CONCLUSIONS

Among Medicare beneficiaries, blacks had less fragmented ambulatory care than whites, due to lower utilization of specialty care. Future research is needed to determine the effect of fragmented care on health outcomes for blacks and whites.

Healthcare Fragmentation and Incident Acute Coronary Heart Disease Events: a Cohort Study

BACKGROUND

Highly fragmented ambulatory care (i.e., care spread across many providers without a dominant provider) has been associated with excess tests, procedures, emergency department visits, and hospitalizations. Whether fragmented care is associated with worse health outcomes, or whether any association varies with health status, is unclear.

OBJECTIVE

To determine whether fragmented care is associated with the risk of incident coronary heart disease (CHD) events, overall and stratified by self-rated general health.

DESIGN AND PARTICIPANTS

We conducted a secondary analysis of the nationwide prospective Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort study (2003-2016). We included participants who were ≥ 65 years old, had linked Medicare fee-for-service claims, and had no history of CHD (N = 10,556).

MAIN MEASURES

We measured fragmentation with the reversed Bice-Boxerman Index. We used Cox proportional hazards models to determine the association between fragmentation as a time-varying exposure and adjudicated incident CHD events in the 3 months following each exposure period.

KEY RESULTS

The mean age was 70 years; 57% were women, and 34% were African-American. Over 11.8 years of follow-up, 569 participants had CHD events. Overall, the adjusted hazard ratio (HR) for the association between high fragmentation and incident CHD events was 1.14 (95% confidence interval (CI) 0.92, 1.39). Among those with very good or good self-rated health, high fragmentation was associated with an increased hazard of CHD events (adjusted HR 1.35; 95% CI 1.06, 1.73; p = 0.01). Among those with fair or poor self-rated health, high fragmentation was associated with a trend toward a decreased hazard of CHD events (adjusted HR 0.54; 95% CI 0.29, 1.01; p = 0.052). There was no association among those with excellent self-rated health.

CONCLUSION

High fragmentation was associated with an increased independent risk of incident CHD events among those with very good or good self-rated health.

Cardiovascular Disease Events and Mortality After Myocardial Infarction Among Black and White Adults: REGARDS Study

BACKGROUND

Despite improvements in prognosis following myocardial infarction (MI), racial disparities persist. The objective of this study was to examine disparities between Black and White adults in cardiovascular disease (CVD), coronary heart disease, stroke, heart failure (HF), and mortality after MI and characteristics that may explain the disparities.

METHODS

This prospective cohort study included 1122 REGARDS (Reasons for Geographic and Racial Differences in Stroke) study participants with incident MI between 2003 and 2016. We followed participants for subsequent CVD events (MI, stroke, HF hospitalization, or death from CVD; n=431), coronary heart disease events (MI or death from coronary heart disease; (n=277), stroke (n=68), HF events (HF hospitalization or death from HF; n=191), and all-cause mortality (n=527; 3-year median follow-up after MI).

RESULTS

Among 1122 participants with incident MI, 37.5% were Black participants, 45.4% were women, and mean age was 73.2 (SD, 9.5) years. The unadjusted hazard ratio for CVD events comparing Black to White participants was 1.42 (95% CI, 1.17-1.71). Adjusting for sociodemographic characteristics did not attenuate the association (1.41 [95% CI, 1.14-1.73]), but further adjusting for pre-MI health status (1.25 [95% CI, 1.00-1.56]) and characteristics of the MI (1.01 [95% CI, 0.80-1.27]) resulted in substantial attenuation. Similar patterns were observed for the other outcomes, although the number of strokes was small.

CONCLUSIONS

Black individuals had a higher risk of CVD events and mortality after MI than White individuals. The disparities were explained by health status before MI and characteristics of the MI. These findings suggest that both primordial prevention of risk factors and improved acute treatment strategies are needed to reduce disparities in post-MI outcomes.

Prompt Outpatient Care For Older Adults Discharged From The Emergency Department Reduces Recidivism

INTRODUCTION

Older adults present unique challenges to both emergency clinicians and health systems. These challenges are especially evident with respect to discharge after an emergency department (ED) visit as older adults are at risk for short-term, negative outcomes including repeat ED visits. The aim of this study was to evaluate characteristics and risk factors associated with repeat ED utilization by older adults.

METHODS

ED visits among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study between 2003-2016 were examined using linked Medicare claims data to identify such visits and resulting disposition. Multilevel proportional hazards models examined associations of age, comorbidity status, race, gender, Medicaid dual eligibility status, social support characteristics (living alone or caregiver support), and use of ambulatory primary and subspecialty care with repeat ED utilization.

RESULTS

Older adults discharged from the ED seen by a primary care provider (hazard ratio [HR] = 0.93, confidence interval [CI], 0.87-0.98, p = 0.01) or subspecialist (HR = 0.91, CI 0.86-0.97, P <0.01) after the ED visit were less likely to return to the ED within 30 days compared to those who did not have such post-ED ambulatory visits. Additionally, comorbidity (HR =1.14, 95% CI, 1.13-1.16, P <0.01) and dual eligibility for Medicare and Medicaid (HR = 1.34, 95% CI, 1.20-1.50, p<0.01) were associated with return to the ED within 30 days. Those who were older (HR = 1.10, 95% CI, 1.05-1.15), had more comorbidities (HR = 1.17, 95% CI 1.15-1.18), Black (HR = 1.23, 95% CI, 1.14-1.33,P <0.01), and dually eligible (HR =1.23, 95% CI, 1.14-1.33, P <0.01) were more likely to return within 31-90 days after their initial presentation. The association of outpatient visits with repeat ED visits was no longer seen beyond 30 days. Patients without a caregiver or who lived alone were no more likely to return to the ED in the time periods evaluated in our study.

CONCLUSION

Both primary care and subspecialty care visits among older adults who are seen in the ED and discharged are associated with less frequent repeat ED visits within 30 days.

Polypharmacy in Older Adults Hospitalized for Heart Failure

BACKGROUND

Despite potential harm that can result from polypharmacy, real-world data on polypharmacy in the setting of heart failure (HF) are limited. We sought to address this knowledge gap by studying older adults hospitalized for HF derived from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke).

METHODS

We examined 558 older adults aged ≥65 years with adjudicated HF hospitalizations from 380 hospitals across the United States. We collected and examined data from the REGARDS baseline assessment, medical charts from HF-adjudicated hospitalizations, the American Hospital Association annual survey database, and Medicare's Hospital Compare website. We counted the number of medications taken at hospital admission and discharge; and classified each medication as HF-related, non-HF cardiovascular-related, or noncardiovascular-related.

RESULTS

The vast majority of participants (84% at admission and 95% at discharge) took ≥5 medications; and 42% at admission and 55% at discharge took ≥10 medications. The prevalence of taking ≥10 medications (polypharmacy) increased over the study period. As the number of total medications increased, the number of noncardiovascular medications increased more rapidly than the number of HF-related or non-HF cardiovascular medications.

CONCLUSIONS

Defining polypharmacy as taking ≥10 medications might be more ideal in the HF population as most patients already take ≥5 medications. Polypharmacy is common both at admission and hospital discharge, and its prevalence is rising over time. The majority of medications taken by older adults with HF are noncardiovascular medications. There is a need to develop strategies that can mitigate the negative effects of polypharmacy among older adults with HF.

Healthcare fragmentation and cardiovascular risk control among older cancer survivors in the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study

Purpose:

Cardiovascular disease (CVD) is the number one cause of death among 5-year cancer survivors. Survivors see many providers and poor coordination may contribute to worse CVD risk factor control. We sought to determine associations between fragmentation and CVD risk factor control among survivors overall and by self-rated health.

Methods:

We included REGARDS participants aged 66+ years who: 1) had a cancer history; 2) reported diabetes, hypertension or hyperlipidemia; and 3) had continuous Medicare coverage. Twelve month ambulatory care fragmentation was calculated using the Bice-Boxerman Index (BBI). We determined associations between fragmentation and CVD risk factors, defining “control” as fasting glucose <126 mg/dL or non-fasting glucose <200 mg/dL for diabetes; blood pressure <140/90 mm Hg for hypertension; and total cholesterol <240 mg/dL, low-density lipoprotein cholesterol <160 mg/dL, or high-density lipoprotein cholesterol >40 mg/dL for hyperlipidemia.

Results:

The 1,002 cancer survivors (2+ years since cancer treatment) had mean age of 75 years, 39% were women, and 23% were Black. Among individuals with diabetes (N=225), hypertension (N=660), and hyperlipidemia (N=516), separately, approximately 60% had CVD risk factor control. Overall, more fragmented care was not associated with worse control. However, among cancer survivors with excellent, very good or good health, more fragmentation was associated with a decreased likelihood of diabetes control (OR 0.78, 95% CI 0.61–0.99), adjusting for confounders.

Conclusions:

More fragmented care was associated with worse glycemic control among cancer survivors with diabetes who reported excellent, very good, or good health. Associations were not observed for control of hypertension or hyperlipidemia.

Implications for cancer survivors:

Reducing fragmentation may support glucose control among survivors with diabetes.

Evaluation of Racial Disparities in Hospice Use and End-of-Life Treatment Intensity in the REGARDS Cohort

IMPORTANCE

Although hospice use is increasing and patients in the US are increasingly dying at home, racial disparities in treatment intensity at the end of life, including hospice use, remain.

OBJECTIVE

To examine differences between Black and White patients in end-of-life care in a population sample with well-characterized causes of death.

DESIGN, SETTING, AND PARTICIPANTS

This study used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, an ongoing population-based cohort study with enrollment between January 25, 2003, and October 3, 2007, with linkage to Medicare claims data. Multivariable logistic regression models were used to examine racial and regional differences in end-of-life outcomes and in stroke mortality among 1212 participants with fee-for-service Medicare who died between January 1, 2013, and December 31, 2015, owing to natural causes and excluding sudden death, with oversampling of Black individuals and residents of Southeastern states in the United States. Initial analyses were conducted in March 2019, and final primary analyses were conducted in February 2020.

MAIN OUTCOMES AND MEASURES

The primary outcomes of interest were hospice use of 3 or more days in the last 6 months of life derived from Medicare claims files. Other outcomes included multiple hospitalizations, emergency department visits, and use of intensive procedures in the last 6 months of life. Cause of death was adjudicated by an expert panel of clinicians using death certificates, proxy interviews, autopsy reports, and medical records.

RESULTS

The sample consisted of 1212 participants (630 men [52.0%]; 378 Black individuals [31.2%]; mean [SD] age at death, 81.0 [8.6] years) of 2542 total deaths. Black decedents were less likely than White decedents to use hospice for 3 or more days (132 of 378 [34.9%] vs 385 of 834 [46.2%]; P < .001). After stratification by cause of death, substantial racial differences in treatment intensity and service use were found among persons who died of cardiovascular disease but not among patients who died of cancer. In analyses adjusted for cause of death (dementia, cancer, cardiovascular disease, and other) and clinical and demographic variables, Black decedents were significantly less likely to use 3 or more days of hospice (odds ratio [OR], 0.72; 95% CI, 0.54-0.96) and were more likely to have multiple emergency department visits (OR, 1.35; 95% CI, 1.01-1.80) and hospitalizations (OR, 1.39; 95% CI, 1.02-1.89) and undergo intensive treatment (OR, 1.94; 95% CI, 1.40-2.70) in the last 6 months of life compared with White decedents.

CONCLUSIONS AND RELEVANCE

Despite the increase in the use of hospice care in recent decades, racial disparities in the use of hospice remain, especially for noncancer deaths. More research is required to better understand racial disparities in access to and quality of end-of-life care.

Comparison of blood lead concentrations in patients with acute ischemic stroke and healthy subjects

BACKGROUND AND OBJECTIVES

Stroke is the main cause of mortality and long-term disability in the general population. With the increased application of metals in industries and human environment, lead has become a health hazard. In this study, we aimed to evaluate the relationship between the blood concentration of lead and the incidence of acute stroke.

MATERIALS AND METHODS

We performed this study during 2016-17 at Vali-e-Asr Hospital in Birjand, Iran, among 80 ischemic stroke patients visiting the hospital and 80 healthy gender- and age-matched controls. Blood lead concentration (BLC) was measured using graphite furnace atomic absorption spectrometry.

RESULTS

BLC medians in the case and control groups were 20.65 [5.37-34.87] μg/dL and 2.65 [1.75-13.85] μg/dL, respectively (p < 0.05). The case group had significantly lower mean levels of HDL and phosphors, whereas the mean levels of white blood cells and uric acid were higher in this group. After adjusting for lipid profile and fasting blood sugar, multiple logistic regression indicated that the serum levels of uric acid and BLC were significant for predicting ischemic stroke. It is estimated that the odds ratio of ischemic stroke increases by 1.04 per 1 μg/dl increase in BLC.

CONCLUSION

This study showed that lead can be a risk factor for ischemic stroke. Since it does not have any beneficial effects on the health of individuals, screening serum concentrations of lead can be considered as a preventive strategy for those at risk of stroke.

Gout is associated with an increased risk for incident heart failure among older adults: the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study

Background

Gout has been associated with a higher risk for coronary heart disease (CHD) and stroke in some prior studies. Few studies have assessed the association of gout with incident heart failure (HF).

Methods

We analyzed data from 5713 black and white men and women ≥ 65.5 years of age in the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study who had Medicare coverage without a history of HF, CHD, or stroke at baseline between 2003 and 2007. Gout was defined by ≥ 1 hospitalization or ≥ 2 outpatient visits with a diagnosis code for gout in Medicare claims prior to each participant’s baseline study examination. REGARDS study participants were followed for HF hospitalization, CHD, stroke, and all-cause mortality as separate outcomes through December 31, 2016. Analyses were replicated in a random sample of 839,059 patients ≥ 65.5 years of age with Medicare coverage between January 1, 2008, and June 30, 2015, who were followed through December 31, 2017.

Results

Among REGARDS study participants included in the current analysis, the mean age at baseline was 72.6 years, 44.9% were men, 31.4% were black, and 3.3% had gout. Over a median follow-up of 10.0 years, incidence rates per 1000 person-years among participants with and without gout were 13.1 and 4.4 for HF hospitalization, 16.0 and 9.3 for CHD, 9.3 and 8.2 for stroke, and 55.0 and 37.1 for all-cause mortality, respectively. After multivariable adjustment for sociodemographic variables and cardiovascular risk factors, hazard ratios (95% CI) comparing participants with versus without gout were 1.97 (1.22, 3.19) for HF hospitalization, 1.21 (0.79, 1.84) for CHD, 0.83 (0.48, 1.43) for stroke, and 1.08 (0.86, 1.35) for all-cause mortality. The multivariable-adjusted hazard ratio for HF hospitalization with reduced and preserved left ventricular ejection fraction among participants with versus without gout was 1.77 (95% CI 0.83, 3.79) and 2.32 (95% CI 1.12, 4.79), respectively. The multivariable-adjusted hazard ratio for heart failure hospitalization associated with gout among the 839,059 Medicare beneficiaries was 1.32 (95% CI 1.25, 1.39).

Conclusion

Among older adults, gout was associated with an increased risk for incident HF but not for incident CHD, incident stroke, or all-cause mortality.

Differences in ambulatory care fragmentation between cancer survivors and noncancer controls

BACKGROUND

Patients with chronic conditions are treated by many providers, which can increase the risk of communication gaps across providers and potential harm to patients. However, to the authors' knowledge, the extent of fragmented care among this population is unknown. In the current study, the authors sought to determine whether cancer survivors have more fragmented care than noncancer controls and to quantify the extent of fragmentation.

METHODS

Data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study linked to Medicare claims were used. The authors included beneficiaries with continuous Part A and B coverage for 12 months at the time of their baseline REGARDS survey. The primary outcome of the current study was claims-based fragmentation over 12 months, which was calculated using the reversed Bice-Boxerman Index so a higher score reflected greater fragmentation. Unadjusted differences in fragmentation were compared between cancer survivors and controls. Beta regression models were used to estimate associations between cancer status and fragmentation, adjusting for potential confounders.

RESULTS

The authors included 4922 participants aged ≥65 years at baseline. Of these patients, approximately 21% were cancer survivors. Survivors had a median of 11 visits (interquartile range, 7-15 visits) with 5 providers compared with controls, who had a median of 9 visits (interquartile range, 6-14 visits) with 4 providers (P < .0001). Cancer survivors had significantly more fragmented care compared with controls (median reversed Bice-Boxerman Index, 0.80 vs 0.76; P < .0001). After adjusting for confounders, cancer survivors had an increased odds of having fragmented care (odds ratio, 1.08; 95% CI, 1.02-1.14).

CONCLUSIONS

Care fragmentation is more prevalent among cancer survivors compared with those without a history of cancer. Future studies should examine whether fragmentation puts survivors at risk of worse outcomes.

Assembling and validating a heart failure-free cohort from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

Background

Studies examining incident heart failure (HF) have been limited to select populations. To examine incident HF with broader generalizability, there is need to assemble a HF-free cohort using a geographically-diverse sample. We aimed to develop and validate a simple medication-based strategy for assembling a HF-free cohort from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study.

Methods

We examined REGARDS participants with ≥6 months of Medicare inpatient and outpatient claims data at the time of the baseline in-home study examination. To assemble a HF-free cohort, we identified and excluded participants taking HF-specific medications. To validate this approach, we evaluated event rates among this cohort and assessed diagnostic performance using Medicare claims-based definitions of HF as the referent standard.

Results

Among 28,884 eligible participants, 3125 were excluded from the proposed HF-free cohort, leaving a total of 25,759 (89%) participants. Depending on the Medicare definition used as the referent, the negative predictive value of this approach ranged from 95.0–99.2%. Negative predictive value was stable across age, sex, and race strata.

Conclusions

The approach to assemble a HF-free cohort in REGARDS can serve as the basis for future studies to examine incident HF in REGARDS and similar studies.

Agreement of claims-based methods for identifying sepsis with clinical criteria in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort

BACKGROUND

Claims-based algorithms are commonly used to identify sepsis in health services research because the laboratory features required to define clinical criteria may not be available in administrative data.

METHODS

We evaluated claims-based sepsis algorithms among adults in the US aged ≥65 years with Medicare health insurance enrolled in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Suspected infections from baseline (2003-2007) through December 31, 2012 were analyzed. Two claims-based algorithms were evaluated: (1) infection plus organ dysfunction diagnoses or sepsis diagnoses (Medicare-Implicit/Explicit) and (2) Centers for Medicare and Medicaid Services Severe Sepsis/Septic Shock Measure diagnoses (Medicare-CMS). Three classifications based on clinical criteria were used as standards for comparison: (1) the sepsis-related organ failure assessment (SOFA) score (REGARDS-SOFA), (2) "quick" SOFA (REGARDS-qSOFA), and (3) Centers for Disease Control and Prevention electronic health record criteria (REGARDS-EHR).

RESULTS

There were 2217 suspected infections among 9522 participants included in the current study. The total number of suspected infections classified as sepsis was 468 for Medicare-Implicit/Explicit, 249 for Medicare-CMS, 541 for REGARDS-SOFA, 185 for REGARDS-qSOFA, and 331 for REGARDS-EHR. The overall agreement between Medicare-Implicit/Explicit and REGARDS-SOFA, REGARDS-qSOFA, and REGARDS-EHR was 77, 79, and 81%, respectively, sensitivity was 46, 53, and 57%, and specificity was 87, 82, and 85%. Comparing Medicare-CMS and REGARDS-SOFA, REGARDS-qSOFA, and REGARDS-EHR, agreement was 77, 87, and 85%, respectively, sensitivity was 27, 41, and 36%, and specificity was 94, 92, and 93%. Events meeting the REGARDS-SOFA classification had a lower 90-day mortality rate (140.7 per 100 person-years) compared with the Medicare-CMS (296.1 per 100 person-years), REGARDS-qSOFA (238.6 per 100 person-years), Medicare-Implicit/Explicit (219.4 per 100 person-years), and REGARDS-EHR classifications (201.8 per 100 person-years).

CONCLUSION

Claims-based sepsis algorithms have high agreement and specificity but low sensitivity when compared with clinical criteria. Both claims-based algorithms identified a patient population with similar 90-day mortality rates as compared with classifications based on qSOFA and EHR criteria but higher mortality relative to SOFA criteria.

Characteristics and Cardiovascular Disease Event Rates among African Americans and Whites Who Meet the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) Trial Inclusion Criteria

PURPOSE

Determine the risk for cardiovascular disease (CVD) events among adults with clinically evident CVD who meet the inclusion criteria for the FOURIER clinical trial on PCSK9 inhibition in a real-world database.

METHODS

We analyzed data from 2072 African American and 2972 white REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants 45-85 years of age with clinically evident CVD. Study participants meeting the FOURIER inclusion criteria (one major or two minor cardiovascular risk factors, fasting LDL cholesterol ≥ 70 mg/dL or non-HDL cholesterol ≥ 100 mg/dL, triglycerides ≤ 400 mg/dL, and taking statin) were followed for CVD events (myocardial infarction, stroke, coronary revascularization, and CVD death) from baseline in 2003-2007 through 2014.

RESULTS

Overall, 771 (37.2%) African Americans and 1200 (40.4%) whites met the FOURIER inclusion criteria. The CVD event rate per 1000 person years was 60.6 (95% CI 53.6-67.6) among African Americans and 63.5 (95% CI 57.7-69.3) among whites. The risk for CVD events among adults meeting the FOURIER inclusion criteria was higher for those with a history of multiple cardiovascular events (hazard ratios among African Americans and whites 1.34 [95% CI 1.05-1.71] and 1.34 [1.10-1.63], respectively), a prior coronary revascularization (1.44 [1.13-1.84] and 1.23 [1.00-1.52], respectively), diabetes (1.38 [1.08-1.76] and 1.41 [1.15-1.72], respectively), reduced glomerular filtration rate (1.63 [1.26-2.11] and 1.29 [1.03-1.62], respectively), and albuminuria (1.77 [1.37-2.27] and 1.33 [1.07-1.65], respectively).

CONCLUSIONS

The CVD event rate is high among African Americans and whites meeting the FOURIER inclusion criteria. Characteristics associated with a higher CVD risk may inform the decision to initiate PCSK9 inhibition.

The Design and Validation of a New Algorithm to Identify Incident Fractures in Administrative Claims Data

Our study validated a claims-based algorithm for the identification of incident and recurrent fractures in administrative data. We used Centers for Medicare and Medicaid (CMS) claims from 2005 to 2014 linked to the Reasons for Geographic and Racial Differences in Stroke (REGARDS) database. Case qualifying (CQ) fractures were identified among participants with ≥12 months of fee-for-service coverage before first fracture claim and ≥6 months after. Recurrent fractures were defined as the first CQ fracture that occurred following a clean period of at least 90 days from the last claim associated with the preceding incident fracture. We used medical records (discharge summary, imaging, and surgical report) to adjudicate fractures. We calculated positive predictive values (PPVs) for incident and recurrent fractures. Our study was not designed to assess the algorithm sensitivity or negative predictive value. We identified 2049 potential incident fractures from claims among 1650 participants. Record retrieval was attempted for 728 (35.5%) suspected incident fractures (prioritizing more recent CQ fractures associated with osteoporosis, but without explicitly requiring any osteoporosis ICD-9 diagnosis code). Our final sample included 520 claims-identified fractures with medical records, of which 502 (96.5%) were confirmed. The PPVs (95% CI) of the hip, wrist, humerus, and clinical vertebra-all exceeded 95%. We identified 117 beneficiaries with 292 ≥2 CQ fracture episodes at the same site, and attempted retrieval on 105 (36.0%) episodes. Our analytic sample included 72 (68.5%) CQ episodes from 33 participants. The PPVs for identifying recurrent clinical vertebral, hip/femur, and nonvertebral fractures with a 90-day clean period exceeded 95%. Although we could not ascertain sensitivity, our updated fracture identification algorithms had high PPV for the identification of incident and recurrent fractures of the same site. Although medical record review and clinical adjudication remain a gold standard, our claims-based algorithm provides an alternative approach to fracture ascertainment when high PPV is desired. © 2019 American Society for Bone and Mineral Research.

The risk of arterial thromboembolic events after cancer diagnosis

BACKGROUND

Retrospective studies have reported an association between cancer and arterial thromboembolic event (ATE) risk.

OBJECTIVES

We sought to confirm this in a prospective cohort with adjudicated outcomes.

METHODS

We evaluated participants enrolled in the REGARDS (REasons for Geographic and Racial Differences in Stroke) study with Medicare coverage for 365 days before their baseline visit (2003-2007). Medicare claims were used to identify new cancer diagnoses during follow-up. Using incidence-density sampling, participants who developed cancer were matched by age, sex, race, and education 1:4 to control participants who had not developed cancer. Participants were prospectively followed through 2015 for an expert-adjudicated ATE, defined as acute myocardial infarction or ischemic stroke. Cox regression was performed to evaluate the association between incident cancer and subsequent ATE.

RESULTS

In this analysis, 836 REGARDS participants with incident cancer were matched to 3339 control participants without cancer. In the 30 days after cancer diagnosis, 0.60% (n = 5) of the participants had an ATE; most of these events occurred near the time of cancer diagnosis. After adjustment for demographics, geographic region, and cardiovascular risk factors, compared to the noncancer controls, participants with incident cancer had an increased risk of ATE in the first 30 days after diagnosis (hazard ratio, 5.8; 95% confidence interval, 2.1-15.9). There was no association between cancer diagnosis and ATE beyond 30 days. Cancers with known metastases and types considered high risk for venous thromboembolism had the strongest associations with ATE.

CONCLUSIONS

Incident cancer is associated with an increased short-term risk of ATE independent of vascular risk factors.

Validation of the REGARDS Severe Sepsis Risk Score

There are no validated systems for characterizing long-term risk of severe sepsis in community-dwelling adults. We tested the ability of the REasons for Geographic and Racial Differences in Stroke-Severe Sepsis Risk Score (REGARDS-SSRS) to predict 10-year severe sepsis risk in separate cohorts of community-dwelling adults. We internally tested the REGARDS-SSRS on the REGARDS-Medicare subcohort. We then externally validated the REGARDS-SSRS using (1) the Cardiovascular Health Study (CHS) and (2) the Atherosclerosis Risk in Communities (ARIC) cohorts. Participants included community-dwelling adults: REGARDS-Medicare, age ≥65 years, n = 9522; CHS, age ≥65 years, n = 5888; ARIC, age 45–64 years, n = 11,584. The primary exposure was 10-year severe sepsis risk, predicted by the REGARDS-SSRS from participant sociodemographics, health behaviors, chronic medical conditions and select biomarkers. The primary outcome was first severe sepsis hospitalizations, defined as the concurrent presence of ICD-9 discharge diagnoses for a serious infection and organ dysfunction. Median SSRS in the cohorts were: REGARDS-Medicare 11 points (IQR 7–16), CHS 10 (IQR 6–15), ARIC 7 (IQR 5–10). Severe sepsis incidence rates were: REGARDS-Medicare 30.7 per 1000 person-years (95% CI: 29.2–32.2); CHS 11.9 (10.9–12.9); ARIC 6.8 (6.3–7.3). SSRS discrimination for first severe sepsis events were: REGARDS-Medicare C-statistic 0.704 (95% CI: 0.691–0.718), CHS 0.696 (0.675–0.716), ARIC 0.697 (0.677–0.716). The REGARDS-SRSS may potentially play a role in identifying community-dwelling adults at high severe sepsis risk.

Use of Medicare Claims Data for the Identification of Myocardial Infarction: The Reasons for Geographic And Racial Differences in Stroke Study

OBJECTIVES

Assess the validity of Medicare claims for identifying myocardial infarction (MI).

METHODS

We used data from 9951 Medicare beneficiaries 65 years and above in the Reasons for Geographic And Racial Differences in Stroke study. Between 2003 and 2012, 669 participants had an MI identified and adjudicated through study procedures (ie, the gold standard), and 552 had an overnight inpatient claim with a code for MI (ICD-9 code 410.x0 or 410.x1) in any discharge diagnosis position.

RESULTS

Using Medicare claims with a discharge diagnosis code for MI in any position, the positive predictive value (PPV) was 84.3% [95% confidence interval (CI), 80.9%-87.3%] and the sensitivity was 49.0% (95% CI, 44.9%-53.1%). Sensitivity was lower for men (45.8%) versus women (55.1%), microsize MIs (13.7%) versus other MIs (64.7%), type 2 (30.9%), and 4-5 MIs (11.1%) versus type 1 MIs (76.6%), and MIs occurring in-hospital (28.8%) versus out-of-hospital (66.7%). Using Medicare claims with a code for MI in the primary discharge diagnosis position, the PPV was 89.7% (95% CI, 86.3%-92.5%) and sensitivity was 40.1% (95% CI, 36.1%-44.2%). The sensitivity of claims with a code for MI in the primary discharge diagnosis position was lower for microsize versus other MIs, type 2 and 4-5 MIs versus type 1 MIs and MIs occurring in-hospital versus out-of-hospital. Hazard ratios for MI associated with participant characteristics were similar using adjudicated MIs identified through study procedures or claims for MI without further adjudication.

CONCLUSIONS

Medicare claims have a high PPV but low sensitivity for identifying MI and can be used to investigate individual-level characteristics associated with MI.

Development of algorithms for identifying fatal cardiovascular disease in Medicare claims

BACKGROUND

Cause of death is often not available in administrative claims data.

OBJECTIVE

To develop claims-based algorithms to identify deaths due to fatal cardiovascular disease (CVD; ie, fatal coronary heart disease [CHD] or stroke), CHD, and stroke.

METHODS

Reasons for Geographic and Racial Differences in Stroke (REGARDS) study data were linked with Medicare claims to develop the algorithms. Events adjudicated by REGARDS study investigators were used as the gold standard. Stepwise selection was used to choose predictors from Medicare data for inclusion in the algorithms. C-index, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were used to assess algorithm performance. Net reclassification index (NRI) was used to compare the algorithms with an approach of classifying all deaths within 28 days following hospitalization for myocardial infarction and stroke to be fatal CVD.

RESULTS

Data from 2,685 REGARDS participants with linkage to Medicare, who died between 2003 and 2013, were analyzed. The C-index for discriminating fatal CVD from other causes of death was 0.87. Using a cut-point that provided the closest observed-to-predicted number of fatal CVD events, the sensitivity was 0.64, specificity 0.90, PPV 0.65, and NPV 0.90. The algorithms resulted in positive NRIs compared with using deaths within 28 days following hospitalization for myocardial infarction and stroke. Claims-based algorithms for discriminating fatal CHD and fatal stroke performed similarly to fatal CVD.

CONCLUSION

The claims-based algorithms developed to discriminate fatal CVD events from other causes of death performed better than the method of using hospital discharge diagnosis codes.

Does Identification of Previously Undiagnosed Conditions Change Care-Seeking Behavior?

OBJECTIVE

To determine whether identification of previously undiagnosed high cholesterol, hypertension, and/or diabetes during an in-home assessment impacts care seeking among Medicare beneficiaries.

DATA SOURCES/STUDY SETTING

Data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, which recruited African American and white participants across the continental United States from 2003-2007, were linked to Medicare claims.

STUDY DESIGN

We used panel data models to analyze changes in doctor visits for evaluation and management of conditions after participants were assessed, utilizing the study's rolling recruitment to control for secular trends.

DATA EXTRACTION METHODS

We extracted Medicare claims for the 24 months before through 24 months after assessment via REGARDS for 5,884 participants.

PRINCIPAL FINDINGS

Semi-annual doctor visits for previously undiagnosed conditions increased by 22 percentage points (95 percent confidence interval: 16-28) 2 years following assessment. The effect was similar by gender, race, region, and Medicaid, but it may have been lower among participants who lacked a usual health care provider.

CONCLUSIONS

In-home assessment of cholesterol, blood pressure, and blood glucose can increase doctor visits for individuals with previously undiagnosed conditions. However, biomarker assessment may have more limited impact among individuals with low access to care.

New diagnosis of cancer and the risk of subsequent cerebrovascular events

OBJECTIVE

We aimed to evaluate the association between cancer and cerebrovascular disease in a prospective cohort study with adjudicated cerebrovascular diagnoses.

METHODS

We analyzed participants from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who were 45 years and older and had Medicare coverage for 365 days before their baseline study visit. Participants with a history of cancer or cerebrovascular events were excluded. The time-dependent exposure was a new diagnosis of malignant cancer identified through Medicare claims algorithms. Participants were prospectively followed from their baseline study visit (2003-2007) through 2014 for the outcome of a neurologist-adjudicated cerebrovascular event defined as a composite of stroke (ischemic or hemorrhagic) or TIA. Cox regression was used to evaluate the association between a new cancer diagnosis and subsequent cerebrovascular events. Follow-up time was modeled in discrete time periods to fulfill the proportional hazard assumption.

RESULTS

Among 6,602 REGARDS participants who met eligibility criteria, 1,149 were diagnosed with cancer during follow-up. Compared to no cancer, a new cancer diagnosis was associated with subsequent cerebrovascular events in the first 30 days after diagnosis (hazard ratio 6.1, 95% confidence interval 2.7-13.7). This association persisted after adjustment for demographics, region of residence, and vascular risk factors (hazard ratio 6.6, 95% confidence interval 2.7-16.0). There was no association between cancer diagnosis and incident cerebrovascular events beyond 30 days. Cancers considered high risk for venous thromboembolism demonstrated the strongest associations with cerebrovascular event risk.

CONCLUSION

A new diagnosis of cancer is associated with a substantially increased short-term risk of cerebrovascular events.

Men Lacking a Caregiver Have Greater Risk of Long-Term Nursing Home Placement After Stroke

BACKGROUND/OBJECTIVES

Social support can prevent or delay long-term nursing home placement (NHP). The purpose of our study was to understand how the availability of a caregiver can affect NHP after ischemic stroke and how this affects different subgroups differently.

DESIGN

Nested cohort study.

SETTING

Nationally based REasons for Geographic and Racial Differences in Stroke (REGARDS) study.

PARTICIPANTS

Stroke survivors aged 65 to 100 (256 men, 304 women).

MEASUREMENTS

Data were from Medicare claims from January 2003 to December 2013 and REGARDS baseline interviews conducted from January 2003 to October 2007. Caregiver support was measured by asking, "If you had a serious illness or became disabled, do you have someone who would be able to provide care for you on an on-going basis?" Diagnosis of ischemic stroke was derived from inpatient claims. NHP was determined using a validated claims algorithm for stays of 100 days and longer. Risk was estimated using Cox regression.

RESULTS

Within 5 years of stroke, 119 (21.3%) participants had been placed in a nursing home. Risk of NHP was greater in those lacking available caregivers (log-rank P = .006). After adjustment for covariates, lacking an available caregiver increased the risk of NHP after stroke within 1 year by 70% (hazard ratio (HR) = 1.70, 95% confidence interval (CI) = 0.97-2.99) and within 5 years by 68% (HR = 1.68, 95% CI = 1.10-2.58). The effect of caregiver availability on NHP within 5 years was limited to men (HR = 3.15, 95% CI = 1.49-6.67).

CONCLUSION

In men aged 65 and older who have survived an ischemic stroke, the lack of an available caregiver is associated with triple the risk of NHP within 5 years.

Medical therapy following hospitalization for heart failure with reduced ejection fraction and association with discharge to long-term care: a cross-sectional analysis of the REasons for Geographic And Racial Differences in Stroke (REGARDS) population

BACKGROUND

Less intensive treatment for heart failure with reduced ejection fraction (HFrEF) may be appropriate for patients in long-term care settings because of limited life expectancy, frailty, comorbidities, and emphasis on quality of life.

METHODS

We compared treatment patterns between REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants discharged to long-term care versus home following HFrEF hospitalizations. We examined medical records and Medicare pharmacy claims for 147 HFrEF hospitalizations among 80 participants to obtain information about discharge disposition and medication prescriptions and fills.

RESULTS

Discharge to long-term care followed 22 of 147 HFrEF hospitalizations (15%). Participants discharged to long-term care were more likely to be prescribed beta-blockers and less likely to be prescribed aldosterone receptor antagonists and hydralazine/isosorbide dinitrate (96%, 14%, and 5%, respectively) compared to participants discharged home (81%, 22%, and 23%, respectively). The percentages of participants discharged to long-term care and home who had claims for filled prescriptions were similar for beta-blockers (68% versus 66%) and angiotensin converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARBs) (45% versus 47%) after 1 year. Smaller percentages of participants discharged to long-term care had claims for filled prescriptions of other medications compared to participants discharged home (diuretics: long-term care-50%, home-72%; hydralazine/isosorbide dinitrate: long-term care-5%, home-23%; aldosterone receptor antagonists: long-term care-5%, home-23%).

CONCLUSIONS

Differences in medication prescriptions and fills among individuals with HFrEF discharged to long-term care versus home may reflect prioritization of some medical therapies over others for patients in long-term care.

Black-White Differences in Incident Fatal, Nonfatal, and Total Coronary Heart Disease

BACKGROUND

Blacks have higher coronary heart disease (CHD) mortality compared with whites. However, a previous study suggests that nonfatal CHD risk may be lower for black versus white men.

METHODS

We compared fatal and nonfatal CHD incidence and CHD case-fatality among blacks and whites in the Atherosclerosis Risk in Communities study (ARIC), the Cardiovascular Health Study (CHS), and the Reasons for Geographic and Racial Differences in Stroke study (REGARDS) by sex. Participants 45 to 64 years of age in ARIC (men=6479, women=8488) and REGARDS (men=5296, women=7822), and ≥65 years of age in CHS (men=1836, women=2790) and REGARDS (men=3381, women=4112), all without a history of CHD, were analyzed. Fatal and nonfatal CHD incidence was assessed from baseline (ARIC=1987-1989, CHS=1989-1990, REGARDS=2003-2007) through up to 11 years of follow-up.

RESULTS

Age-adjusted hazard ratios comparing black versus white men 45 to 64 years of age in ARIC and REGARDS were 2.09 (95% confidence interval, 1.42-3.06) and 2.11 (1.32-3.38), respectively, for fatal CHD, and 0.82 (0.64-1.05) and 0.94 (0.69-1.28), respectively, for nonfatal CHD. After adjustment for social determinants of health and cardiovascular risk factors, hazard ratios in ARIC and REGARDS were 1.19 (95% confidence interval, 0.74-1.92) and 1.09 (0.62-1.93), respectively, for fatal CHD, and 0.64 (0.47-0.86) and 0.67 (0.48-0.95), respectively, for nonfatal CHD. Similar patterns were present among men ≥65 years of age in CHS and REGARDS. Among women 45 to 64 years of age in ARIC and REGARDS, age-adjusted hazard ratios comparing blacks versus whites were 2.61 (95% confidence interval, 1.57-4.34) and 1.79 (1.06-3.03), respectively, for fatal CHD, and 1.47 (1.13-1.91) and 1.29 (0.91-1.83), respectively, for nonfatal CHD. After multivariable adjustment, hazard ratios in ARIC and REGARDS were 0.67 (95% confidence interval, 0.36-1.24) and 1.00 (0.54-1.85), respectively, for fatal CHD, and 0.70 (0.51-0.97) and 0.70 (0.46-1.06), respectively, for nonfatal CHD. Racial differences in CHD incidence were attenuated among older women. CHD case fatality was higher among black versus white men and women, and the difference remained similar after multivariable adjustment.

CONCLUSIONS

After accounting for social determinants of health and risk factors, black men and women have similar risk for fatal CHD compared with white men and women, respectively. However, the risk for nonfatal CHD is consistently lower for black versus white men and women.

Blood Pressure, Antihypertensive Polypharmacy, Frailty, and Risk for Serious Fall Injuries Among Older Treated Adults With Hypertension

Antihypertensive medication and low systolic blood pressure (BP) and diastolic BP have been associated with an increased falls risk in some studies. Many older adults have indicators of frailty, which may increase their risk for falls. We contrasted the association of systolic BP, diastolic BP, number of antihypertensive medication classes taken, and indicators of frailty with risk for serious fall injuries among 5236 REGARDS study (Reasons for Geographic and Racial Difference in Stroke) participants ≥65 years taking antihypertensive medication at baseline with Medicare fee-for-service coverage. Systolic BP and diastolic BP were measured, and antihypertensive medication classes being taken assessed through a pill bottle review during a study visit. Indicators of frailty included low body mass index, cognitive impairment, depressive symptoms, exhaustion, impaired mobility, and history of falls. Serious fall injuries were defined as fall-related fractures, brain injuries, or joint dislocations using Medicare claims through December 31, 2014. Over a median of 6.4 years, 802 (15.3%) participants had a serious fall injury. The multivariable-adjusted hazard ratio for a serious fall injury among participants with 1, 2, or ≥3 indicators of frailty versus no frailty indicators was 1.18 (95% confidence interval, 0.99-1.40), 1.49 (95% confidence interval, 1.19-1.87), and 2.04 (95% confidence interval, 1.56-2.67), respectively. Systolic BP, diastolic BP, and number of antihypertensive medication classes being taken at baseline were not associated with risk for serious fall injuries after multivariable adjustment. In conclusion, indicators of frailty, but not BP or number of antihypertensive medication classes, were associated with increased risk for serious fall injuries among older adults taking antihypertensive medication.

Comparison of Expert Adjudicated Coronary Heart Disease and Cardiovascular Disease Mortality With the National Death Index: Results From the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

BACKGROUND

The National Death Index (NDI) is widely used to detect coronary heart disease (CHD) and cardiovascular disease (CVD) deaths, but its reliability has not been examined recently.

METHODS AND RESULTS

We compared CHD and CVD deaths detected by NDI with expert adjudication of 4010 deaths that occurred between 2003 and 2013 among participants in the REGARDS (REasons for Geographic And Racial Differences in Stroke) cohort of black and white adults in the United States. NDI derived CHD mortality had sensitivity 53.6%, specificity 90.3%, positive predictive value 54.2%, and negative predictive value 90.1%. NDI-derived CVD mortality had sensitivity 73.4%, specificity 84.5%, positive predictive value 70.6%, and negative predictive value 86.2%. Among NDI-derived CHD and CVD deaths, older age (odds ratios, 1.06 and 1.04 per 1-year increase) was associated with a higher probability of disagreement with the adjudicated cause of death, whereas among REGARDS adjudicated CHD and CVD deaths a history of CHD or CVD was associated with a lower probability of disagreement with the NDI-derived causes of death (odds ratios, 0.59 and 0.67, respectively).

CONCLUSIONS

The modest accuracy and differential performance of NDI-derived cause of death may impact CHD and CVD mortality statistics.

Cardiovascular Health and Healthcare Utilization and Expenditures Among Medicare Beneficiaries: The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

Background

Better cardiovascular health is associated with lower cardiovascular disease risk.

Methods and Results

We determined the association between cardiovascular health and healthcare utilization and expenditures in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. We included 6262 participants ≥65 years with Medicare fee‐for‐service coverage for the year after their baseline study visit in 2003‐2007. Cardiovascular health at baseline was assessed using the American Heart Association's Life's Simple 7 (LS7) metric, which includes 7 factors: cigarette smoking, physical activity, diet, body mass index, blood pressure, cholesterol, and glucose. Healthcare utilization and expenditures were ascertained using Medicare claims in the year following baseline. Overall, 17.2%, 31.1%, 29.0%, 16.4% and 6.4% of participants had 0 to 1, 2, 3, 4, and 5 to 7 ideal LS7 factors, respectively. The multivariable‐adjusted relative risk (95% confidence interval [CI]) for having any inpatient and outpatient encounters comparing participants with 5 to 7 versus 0 to 1 ideal LS7 factors were 0.55 (0.39, 0.76) and 1.00 (0.98, 1.02), respectively. Among participants with 0 to 1 and 5 to 7 ideal LS7 factors, mean inpatient expenditures were $3995 and $1250, respectively, mean outpatient expenditures were $5166 and $2853, respectively, and mean total expenditures were $9147 and $4111, respectively. After multivariable adjustment, the mean (95% CI) cost difference comparing participants with 5 to 7 versus 0 to 1 ideal LS7 factors was −$2551 (−$3667, −$1435) for inpatient, −$2410 (−$3089, −$1731) for outpatient, and −$5016 (−$6577, −$3454) for total expenditures.

Conclusions

Better cardiovascular health is associated with lower risk for inpatient encounters and lower inpatient and outpatient healthcare expenditures.

Agreement between Medicare pharmacy claims, self-report, and medication inventory for assessing lipid-lowering medication use

BACKGROUND

Medicare claims have been used to study lipid-lowering medication (LLM) use among US adults.

METHODS

We analyzed the agreement between Medicare claims for LLM and LLM use indicated by self-report during a telephone interview and, separately, by a medication inventory performed during an in-home study visit upon enrollment into the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. We included REGARDS participants ≥65 years enrolled in 2006-2007 with Medicare pharmacy benefits (Part D) from 120 days before their telephone interview through their medication inventory (n = 899).

RESULTS

Overall, 39.2% and 39.5% of participants had a Medicare claim for an LLM within 120 days prior to their interview and medication inventory, respectively. Also, 42.7% of participants self-reported using LLMs, and 41.8% had an LLM in their medication inventory. The Kappa statistic (95% confidence interval [CI]) for agreement of Medicare claims with self-report and medication inventory was 0.68 (0.63-0.73) and 0.72 (0.68-0.77), respectively. No Medicare claims for LLMs were present for 22.1% (95%CI: 18.1-26.6%) of participants who self-reported taking LLMs and 18.9% (15.1-23.3%) with LLMs in their medication inventory. Agreement between Medicare claims and self-report was lower among Black male individuals (Kappa = 0.34 [95%CI: 0.14-0.54]) compared with Black female individuals (0.70 [0.61-0.79]), White male individuals (0.65 [0.56-0.75]), and White female individuals (0.79 [0.72-0.86]). Agreement between Medicare claims and the medication inventory was also low among Black male individuals (Kappa = 0.48 [95%CI: 0.29-0.66]).

CONCLUSIONS

Although substantial agreement exists, many Medicare beneficiaries who self-report LLM use or have LLMs in a medication inventory have no claims for these medications. Copyright © 2016 John Wiley & Sons, Ltd.