Analizing Recent Trends in Coronary Heart Disease (CHD) Deaths Among the Elderly in the United States Using Data From Official Statistical Sources

Abstract

Total mortality rates and coronary heart disease (CHD) mortality ratesare declining in the USA. Accordingly, the oldest individuals (85+years) comprise the fastest growing segment of the population. Howdo these declines in mortality apply to and re-apportion other age groups?We examined trends in CHD mortality for the USA population over 25 yearsof age, focusing on changes occurring among individuals 65-74 and 75-84years of age.

Analizing Recent Trends in Coronary Heart Disease (CHD) Deaths Among the Elderly in the United States Using Data From Official Statistical Sources

PROFESSIONAL PAPER

Analizing Recent Trends in Coronary Heart Disease (CHD) Deaths Among the Elderly in the United States Using Data From Official Statistical Sources

Emir Veledar1, Reza Fazel1, Leslee Shaw1, Emir Fazlibegovic2, Mustafa Hadziomerovic2,Emory University, Medicine, Cardiology, Atlanta, GA, USA1, UCH Mostar, Bosnia and Herzegovina2

Total mortality rates and coronary heart disease (CHD) mortality rates are declining in the USA. Accordingly, the oldest individuals (85+ years) comprise the fastest growing segment of the population. How do these declines in mortality apply to and re-apportion other age groups?

We examined trends in CHD mortality for the USA population over 25 years

of age, focusing on changes occurring among individuals 65-74 and 75-84

years of age. Key words: total mortality, coronary heart disease, USA.

Corresponding author: Emir Veledar, PhD, Emory University, Medicine Cardiology, Atlanta, GA, USA.

1. INTRODUCTION

Total mortality rates and coronary heart disease (CHD) mortality rates are declining in the USA. Accordingly, the oldest individuals (85+ years) comprise the fastest growing segment of the population (1,2,3,4). How do these declines in mortality apply to and re-apportion other age groups?

We examined trends in CHD mortality for the USA population over 25 years of age, focusing on changes occur-ring among individuals 65-74 and 75-84 years of age (the so called elderly).

2. METHODS

Using CDC Wonder we extracted data for the period between 1999 and 2006 from the National Center for Health Statistics data base for the entire population and for Caucasian and African American (AA) males and females starting from age 25 years is groups of 10 years. For each group we determined number of individuals, all causes mortality, and deaths from CHD.

CHD deaths were defined as deaths classied in subgroup I20-I25, encompassing more than 90% of all deaths in ICD-10 section, Diseases of the circulatory system.

Log link Poisson regression was used to derive race-and-gender- specic trends after adjusting for age . When we wish to determine the eects of groups or exposure levels, we do this using the standardized mortality ratio (SMR). The SMR is dened as the ratio of two rates. Male-to-female and AA versus Caucasian SMR were calculated.

We created one model for all 8 years, 8 models for each year, and 16 models for 8 years and 2 races. This allowed us to estimate not only the time component but also gender dierence by race.

3. GRAPHS

Five sets of graphs and included numerical data are presented: Number of CHD deaths for each year from 1999 to 2006.

Annual decrease in deaths in each

year compared to year 1999. Percent change in deaths in each year compared to year 1999.

4. RESULTS

CHD death rates between 1999 and 2006 among Caucasians and African Americans in the United States demonstrate an decline in all 4 groups.

Over 8 years, the overall decline in mortality from CHD deaths was 25.2 % in females and 19.5% in males.

Multivariable analysis showed a signicant decrease in CHD mortality across time (p<.001), race (p<.001) and gender (p<.001). SMR for gender was 1.67 indicating that rate for males was 67% higher then for females. SMR for race (AA versus Caucasian) was 1.23.

Decline in CHD deaths for groups 65-74 years and 75-84 years for Caucasian females was (35% and 32%); for AA females (36% and 32%). Deaths among males, both Caucasians (35% and 30%) and African Americans (27% and 22%), declined.

We observed graphically and demonstrated in models that mortality trends for the elderly population dier signicantly from mortality trends in other groups.

Compared to 1999, more than 104,000 additional Americans with CHD survived in 2006 .

More than 76,000 (73% ) of the additional people surviving CHD annually are between 65 to 85 years old, a group

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Analizing Recent Trends in Coronary Heart Disease (CHD) Deaths Among the Elderly in the United States Using Data From Official Statistical Sources

Figure 1. Number of overall CHD deaths for each year from 1999 to 2006. Mortality among the elderly contributed 50% to overall CHD deaths in 1999 and decrease to 45% in 2006

Figure 2. Decline in CHD deaths. Compared to 1999 more than 104.000 additional Americans survived in 2006. More than 76000 (73%) of the additional people are between 65 to 84 years

located between the baby boomers and the oldest old but representing only 11% of the USA population.

Improved survival rates in this group is the major determinant of the unprecedented decline in mortality from CHD in the USA. Mortality among the elderly contributed 50% to overall CHD deaths in 1999 but only 45% in 2006.

4.1. Graph Interpretation

Number of CHD deaths for each year from 1999 to 2006 is presented in upper part of graphs displays. Two youngest age groups (25-34, 35-44) are almost not present and almost invis-

ible in graphs. Next 2 age groups (45-54 and 55-64), representing proportionally signicant segment, so called baby boomers, a marked in light green and lilac. Number of CHD deaths in those two groups, already small, is stagnant or decreasing, even as absolute number and proportions of USA population in these two groups are increasing. Age groups 65-74 and 75-84, depicted on graphs in aqua and orange, are where the biggest drop in absolute number of deaths occurred over this period, values going down from 98840 in 1999 to 66685 in 2006, and from 169296 to 125 225, drop of 32% and 26%.

Annual decrease in deaths in each year compared to year 1999 is presented in a middle part of our graph pane. For each of age group, number of people who died in 1999 in subtracted from number of deaths in corresponding year, illustrating numbers of lives saved in that year and in corresponding age group by changes in CHD mortality.

Percent change in deaths in each year compared to year 1999. This is yet another way of depicting change occur-ring over time, which illustrates acceleration of this positive trend in CHD mortality.

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Analizing Recent Trends in Coronary Heart Disease (CHD) Deaths Among the Elderly in the United States Using Data From Official Statistical Sources

Figure 3. Change in survival (%) compared to 1999. Significant decline in CHD rates in elderly population (65 to 84 years)

5. DISCUSSION

The trend of decreasing mortality from CHD in USA not seen in other countries has apparently accelerated during the last 8 years. CHD death rates have declined almost twofold between 1999 and 2006 when compared to the previous 8 years (5,6,7,8). From Source: Heart Disease and Stroke Statistics -2009 Update data are compared and dissussed in this paper (1).

Decline in CHD death rates in the elderly population (65 to 84 years) is an important contributor to the growing population aged 85 years and older as well as for the dramatic decline in CHD death rates for the overall population of the United States. Despite these trends toward greater longevity, substantial racial and gender dierences persist.

REFERENCES

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2. Centers for Disease Control and Prevention, National Center for Health Statistics. Compressed Mortality File 1999-2006. CDC WONDER On-line Database, compiled from Compressed Mortality File 1999-2006 Series 20 No. 2L, 2009. Accessed at http://wonder.cdc.gov/cmficd10.html on Oct 27, 2009 6:51:35 PM

3. Ford ES, Ajani UA, Croft JB, Critchley JA, Labarthe DR, Kottke TE, et al. Explaining the decrease in U.S. deaths from coronary disease, 1980-2000. N Engl J Med, 2007;356(23):2388-98.

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Old questions and new facts. Am J Med, 1984;76(6):1055-65.5. Goldman L, Cook EF. The decline in ischemic heart disease mortality rates. An analysis of the comparative effects of medical interventions and changes in lifestyle. Ann Intern Med, 1984;101(6):825-36.

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8. Veledar E, Narayan V, Wenger N, Zhao J,Shaw L, Wilson P, Vaccarino V. Trends in Coronary Heart Disease Incidence and Mortality Rates in US Women; Circulation, 2008;117;e198-e291.

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