2008 Atlas of Stroke Hospitalizations Among Medicare Beneficiaries

Introduction

Atlas Topics Home Messages and Foreword Introduction Section One Section Two Section Three Section Four Section Five Section Six Section Seven Appendix A Appendix B Appendix C

Stroke is a major public health issue with direct costs for care estimated at $41.6 billion and indirect costs in terms of lost productivity from either illness or death estimated at an additional $21.1 billion for 2007.¹ At least 2% of all U.S. adults living in households report having had a stroke² and over 65% of white stroke survivors and 47% of black stroke survivors living in households are ages 65 years and older.³ Stroke is a major cause of serious, long-term disability in the United States,⁴ and nearly 45% of all stroke survivors ages 65 years and older have moderate or severe disability.⁵ Stroke has remained the third leading cause of death since 1938.⁶ The numbers and rates for stroke deaths have declined throughout the 20th century;⁷ however, the decline has been less apparent since the 1990s.^8-10 In 2003, stroke accounted for 157,689 deaths among U.S. residents.¹¹

In 2000, the Centers for Disease Control and Prevention (CDC) first placed a focus on stroke by emphasizing (1) prevention and control of all risk factors for stroke along with heart disease, (2) increased awareness of the signs and symptoms of heart attack and stroke, and (3) secondary prevention among persons surviving acute stroke events.²³ In 2001, CDC provided funds to organizations to design and pilot-test statewide Paul Coverdell National Acute Stroke Registry prototypes to measure and improve the quality of care for stroke patients.^24,25 The state-based national cardiovascular health program was renamed the National Heart Disease and Stroke Prevention Program to emphasize the importance of stroke.

In 2003, the Atlas of Stroke Mortality: Racial, Ethnic, and Geographic Disparities in the United States was published to provide health professionals and concerned citizens with information at the local, state, and national levels to identify populations at greatest risk for stroke death and in greatest need of prevention efforts.²²

By 2004, state program priorities were further enhanced to improve the prevention and control of high blood pressure and high cholesterol, improve the quality of cardiovascular disease-related health care, increase public awareness of and emergency response to acute stroke and heart attack, and eliminate health disparities.²⁶ In 2004, CDC funded four state health departments to establish Paul Coverdell National Acute Stroke Registries (Georgia, Illinois, Massachusetts, and North Carolina). In 2007, three additional states were added (Michigan, Minnesota, and Ohio). These registries are designed to monitor and improve the quality of care for acute stroke patients.

To provide additional support to states to monitor and improve the quality of care for stroke, the Atlas of Stroke Hospitalizations Among Medicare Beneficiaries presents national Medicare data at the county level for the aggregated time period of 1995–2002. Stroke hospitalizations were defined as those for which the principal diagnosis on the Medicare hospital claim form was cerebrovascular disease, indicated by codes 430–434 and 436–438 according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). Hospitalizations for which the principal diagnosis was transient ischemic attacks (ICD-9-CM code 435) were excluded.

Data are presented for both women and men and for U.S. racial and ethnic groups, which are limited in this report to blacks, Hispanics, and whites. The national maps allow comparisons across all U.S. counties of hospitalization rates for all strokes and selected stroke subtypes. The proportions of 30-day case fatalities and those discharged to selected destinations following hospitalization for a stroke also are mapped at the county level.

We have also provided maps showing the location of all short-term general hospitals and those with neurological services, emergency departments, and rehabilitation care services.

The major limitation of this report is that the data are from Medicare Part A forms, which are administrative records collected for claims reimbursement and do not constitute a national surveillance system. Because 29% of all stroke hospitalizations in the United States occur among patients younger than 65 years,¹² it is not known whether the geographic patterns in this report of Medicare beneficiaries ages 65 years and older would be similar if the results included younger patients. Another limitation is that the data for race and Hispanic ethnicity are not reported separately. This reporting practice can contribute to the misclassification of race and ethnicity and the underreporting of Hispanics.²⁷ (See Appendix B for more details.)

In addition, Medicare claims do not distinguish between first or recurrent strokes, nor do they indicate the severity of the stroke. Another major limitation of using Medicare claims records is the inability to determine accuracy of physician or administrative reporting of stroke subtype diagnoses, procedures, or comorbid conditions such as hypertension, diabetes, and atrial fibrillation. Variations between states may also reflect either regional patterns in financial incentives to report specific information or regional differences in medical opinion regarding definitions for specific diagnoses.

Furthermore, there is no additional information on the claims record regarding medical management or medical therapy for the hospitalization, hospital characteristics (e.g., urban versus rural, academic medical center versus community hospital, number of beds, average number of stroke patients, availability of stroke units or diagnostic technology), or performance indicators. Despite these limitations, Medicare claims do represent the only currently available source of state-specific and national data that allow assessment of racial/ethnic disparities and mapping of the available information about stroke hospitalizations at the county level.

An important strength of this Atlas is our examination of geographic disparities in stroke hospitalizations for blacks, Hispanics, and whites in the United States. Previous reports have focused predominantly on blacks and whites. Although data quality limitations exist, we hope that presenting these maps will help public health agencies and advocacy groups improve health outcomes for diverse populations. Federal agencies and other organizations have made stroke care an urgent priority and have advocated steps toward improving acute stroke care.^{25, 28-32}

The data presented at the county and state levels give state public health agencies, quality improvement organizations, and their hospital system partners insightful information that should prompt other needs assessments and efforts to improve the availability of diagnostic equipment and hospital stroke teams with expertise in diagnosis and treatment. Better medical reporting of stroke-related information on hospital records and Medicare claims is also needed to determine whether the observed patterns genuinely reflect access to care and other quality of care issues or regional reporting biases.¹⁴ Ideally, advancements in these arenas will help clinicians and hospital systems improve their quality of care for stroke patients.

Resources

1. American Heart Association. Heart Disease and Stroke Statistics—2007 Update. Dallas, TX: American Heart Association; 2007.
    
2. Centers for Disease Control and Prevention. The Burden of Heart Disease and Stroke in the United States: State and National Data, 1999. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention; 2004.
    
3. McGruder HF, Greenlund KJ, Croft JB, Zheng ZJ. Differences in disability among black and white stroke survivors—United States, 2000–2001. Morbidity and Mortality Weekly Report 2005;54(1):3–6.
    
4. Centers for Disease Control and Prevention. Prevalence of disabilities and associated health conditions among adults—United States, 1999. Morbidity and Mortality Weekly Report 2001;50(7):120–25.
    
5. Wolf PA, Kelly-Hayes M, Kase CS, Gresham GE, Beiser A. Prevalence of stroke-related disability: U.S. estimates from the Framingham Study. Neurology 1998;50(4 Suppl 4):A55–A56.
    
6. Centers for Disease Control and Prevention. Declines in deaths from heart disease and stroke—United States, 1900–1999. Morbidity and Mortality Weekly Report 1999;48(30):649–56.
    
7. National Heart, Lung, and Blood Institute. Morbidity and Mortality: 1998 Chartbook on Cardiovascular, Lung, and Blood Diseases. Rockville, MD: U.S. Department of Health and Human Services, National Institutes of Health; 1998.
    
8. Cooper R, Sempos C, Hsieh SC, Kovar MG. Slowdown in the decline of stroke mortality in the United States, 1978–1986. Stroke 1990(9);21:1274–9.
    
9. Centers for Disease Control and Prevention. Cerebrovascular disease mortality and Medicare hospitalization—United States, 1980–1990. Morbidity and Mortality Weekly Report 1992;41(26):477–80.
    
10. Cooper R, Cutler J, Desvigne-Nickens P, et al. Trends and disparities in coronary heart disease, stroke, and other cardiovascular disease in the United States: findings of the National Conference on Cardiovascular Disease Prevention. Circulation 2000;102(25):3137–47.
     
11. Anderson RN, Smith BL. Deaths: leading causes for 2003. National Vital Statistics Reports. Hyattsville, MD: National Center for Health Statistics; 2007.
     
12. Kozak LJ, Owings MF, Hall MJ. National hospital discharge survey: 2002 annual summary with detailed diagnosis and procedure data. Vital Health Statistics. Hyattsville, MD: National Center for Health Statistics; 2005. DHHS Publication No. (PHS) 2005-1729.
     
13. Fang J, Alderman MH. Trend of stroke hospitalization, United States, 1988–1997. Stroke 2001;32(10);2221–6.
     
14. McGruder HF, Croft JB, Zheng ZJ. Characteristics of an “ill-defined” diagnosis for stroke: opportunities for improvement. Stroke 2006;37(3):781–89.
     
15. Hayes DK, Greenlund KJ, Denny CH, Croft JB, Keenan NL. Racial/ethnic and socioeconomic disparities in multiple risk factors for heart disease and stroke—United States, 2003. Morbidity and Mortality Weekly Report 2005;54(5):113–17.
     
16. Greenlund KJ, Neff LJ, Zheng ZJ, et al. LowpublicLow public recognition of major stroke symptoms. American Journal of Preventive Medicine 2003;25(4):315–19.
     
17. Croft JB, Greenlund KJ, Ayala C, Keenan NL, Zheng ZJ, Mensah GA. Awareness of stroke warning signs—17 states and the U.S. Virgin Islands, 2001. Morbidity and Mortality Weekly Report 2004;53(17):359–62.
     
18. Williams JE, Ayala C, Croft JB, et al. State-specific mortality from stroke and distribution of place of death—United States, 1999. Morbidity and Mortality Weekly Report 2002;51(20):429–33.
     
19. Ayala C, Croft JB, Keenan NL, et al. Increasing trends in pre-transport stroke deaths—United States, 1990–1998. Ethnicity Disease 2003;13(Suppl 2):S2-131–S2-137.
     
20. Neyer JR, Greenlund KJ, Denny CH, et al. Prevalence of stroke—United States, 2005. Morbidity and Mortality Weekly Report 2007;56(19):469–74.
     
21. Davis HF, Croft JB, Malarcher AM, et al. Hospitalizations for stroke among adults aged >65 years—United States, 2000. Morbidity and Mortality Weekly Report 2003;52(25):586–9.
     
22. Casper ML, Barnett E, Williams GI, Halverson JA, Braham VE, Greenlund KJ. Atlas of Stroke Mortality: Racial, Ethnic, and Geographic Disparities in the United States. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention; 2003.
     
23. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Program Announcement 00091: State Cardiovascular Health Programs, Notice of Availability of Funds. Federal Register 2000;65(103):34189–95.
     
24. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Program Announcement 01096: Development of Prototypes for the Paul Coverdell National Acute Stroke Registry, Notice of Availability of Funds. Federal Register 2001;66(96):27517–19.
     
25. Wattigney WA, Croft JB, Mensah GA, et al. Establishing data elements for the Paul Coverdell National Acute Stroke Registry: part 1: proceedings of an expert panel. Stroke 2003;34(1):151–6.
     
26. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Program Announcement 02045: Cardiovascular Health Programs, Notice of Availability of Funds. Federal Register 2002;67(40):9281–9.
     
27. Arday SL, Arday DR, Monroe A, Zhang MD. HCFA’s racial and ethnic data: current accuracy and recent improvements. Health Care Financing Review 2000;21(4):107–16.
     
28. Alberts MA, Hademenos G, Latchaw RE, et al. Recommendations for the establishment of primary stroke centers. JAMA 2000;283(23):3102–9.
     
29. Joint Commission on Accreditation of Healthcare Organizations. Primary Stroke Centers. Available at http://www/jcaho.org/dscc/psc/pm_stroke.htm.*
     
30. Schwamm LH, Pancioli A, Acker JE 3rd, et al. Recommendations for the establishment of stroke systems of care: recommendations from the American Stroke Association Task Force on the Development of Stroke Systems. Stroke 2005;36(3):690–703.
     
31. Smaha LA, American Heart Association. The American Heart Association Get With the Guidelines Program. American Heart Journal 2004;148(5 Suppl):S46–S468.
     
32. Alberts MJ, Latchaw RE, Selman WR, et al. Recommendations for comprehensive stroke centers: a consensus statement from the Brain Attack Coalition. Stroke 2005;36(7):1597–618.

 
*Links to non–Federal organizations are provided solely as a service to our users. Links do not constitute an endorsement of any organization by CDC or the Federal Government, and none should be inferred. The CDC is not responsible for the content of the individual organization Web pages found at this link.
 

Page last reviewed: April 9, 2008
Page last modified: April 9, 2008
Content source: Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion