CDC's April 2002 Report On Smoking: Estimates of Selected Health
Consequences of Cigarette Smoking Were Reasonable (17-JUL-03,
GAO-03-942R).
Despite a recent decline in the population that smokes, smoking
is considered the leading cause of preventable death in this
country. According to the Centers for Disease Control and
Prevention (CDC), over 2 million deaths in the 5-year period from
1995 through 1999 were attributable to cigarette smoking. CDC,
part of the Department of Health and Human Services (HHS), is a
primary source of information on the health consequences of
smoking tobacco. CDC reported its most recent estimates of
selected health consequences of cigarette smoking in an April
2002 issue of its publication Morbidity and Mortality Weekly
Report. CDC reported that, on average, over 440,000 deaths, 5.6
million years of potential life lost, $82 billion in
mortality-related productivity losses, and $76 billion in medical
expenditures were attributable to cigarette smoking each year
from 1995 through 1999. CDC and others tasked with making such
estimates face challenges. They build estimates on a set of
assumptions and make choices about the data sources and methods
used, each of which may have limitations that must be weighed
against its advantages. Policymakers at both the state and
federal levels have relied on estimates like these in considering
bans on smoking in public places, taxes on cigarettes, litigation
to recoup medical expenditures, and other matters concerning
tobacco. Thus it is essential that the estimates CDC provides are
sound and that their limitations are clear. In recognition of
this, Congress asked us to review CDC's April 2002 report and
determine whether its estimates of selected health consequences
of cigarette smoking were reasonable. Specifically, we examined
CDC's estimates of (1) deaths and years of potential life lost
and (2) mortality-related productivity losses and medical
expenditures attributable to cigarette smoking.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-03-942R
ACCNO: A07595
TITLE: CDC's April 2002 Report On Smoking: Estimates of Selected
Health Consequences of Cigarette Smoking Were Reasonable
DATE: 07/17/2003
SUBJECT: Cancer
Cancer research
Data collection
Health hazards
Health surveys
Medical research
Public health research
Smoking
Data integrity
******************************************************************
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GAO-03-942R
GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking United
States General Accounting Office Washington, DC 20548
July 17, 2003 The Honorable Richard Burr House of Representatives
Subject: CDC*s April 2002 Report On Smoking: Estimates of Selected Health
Consequences of Cigarette Smoking Were Reasonable Dear Mr. Burr:
Despite a recent decline in the population that smokes, smoking is
considered the leading cause of preventable death in this country.
According to the Centers for Disease Control and Prevention (CDC), over 2
million deaths in the 5- year period from 1995 through 1999 were
attributable to cigarette smoking. CDC, part of the Department of Health
and Human Services (HHS), is a primary source of information on the health
consequences of smoking tobacco. CDC reported its most recent estimates of
selected health consequences of cigarette smoking in an April 2002 issue
of its publication Morbidity and Mortality Weekly Report. 1 CDC reported
that, on average, over 440,000 deaths, 5.6 million years of potential life
lost, $82 billion in mortality- related productivity losses, and $76
billion in medical expenditures were attributable to cigarette smoking
each year from 1995 through 1999. (See enclosures I and II.)
CDC and others tasked with making such estimates face challenges. They
build estimates on a set of assumptions and make choices about the data
sources and methods used, each of which may have limitations that must be
weighed against its advantages. Policymakers at both the state and federal
levels have relied on estimates like these in considering bans on smoking
in public places, taxes on cigarettes, litigation to recoup medical
expenditures, and other matters concerning tobacco. Thus it is essential
that the estimates CDC provides are sound and that their limitations are
clear. In recognition of this, you asked us to review CDC*s April 2002
report and determine whether its estimates of selected health consequences
of cigarette smoking were reasonable. Specifically, we examined CDC*s
estimates of (1) deaths and years of potential life lost and (2)
mortality- related productivity losses and medical expenditures
attributable to cigarette smoking.
1 Centers for Disease Control and Prevention (CDC), *Annual Smoking-
Attributable Mortality, Years of Potential Life Lost, and Economic Costs *
United States, 1995- 1999,* Morbidity and Mortality Weekly Report, vol.
51, no. 14 (2002): 300- 303. Morbidity and Mortality Weekly Report is a
CDC publication for dissemination of information about the public health
issues in which CDC is involved.
2 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking To
determine whether CDC*s estimates were reasonable, we reviewed CDC*s
approach and alternative approaches to developing them. Specifically, we
reviewed
CDC*s assumptions, methods, and data sources; the choices CDC made about
how to best estimate the number of deaths, years of potential life lost,
productivity losses, and medical expenditures attributable to cigarette
smoking; and CDC*s attempts to deal with the limitations inherent in
analyses of this kind. We examined CDC*s choices in the context of the
alternatives available and determined whether the alternatives would have
resulted in more reasonable estimates. In reviewing CDC*s approach and the
available alternatives, we searched the scientific literature using the
electronic databases MEDLINE and EconLit and reviewed over 200 studies on
the consequences of tobacco and approaches to estimating them. In
addition, we reviewed CDC*s documentation of its methods and interviewed
CDC officials
involved in the report about their approach and their rationale for
choices made in deriving these estimates. We conducted our work from
December 2002 through July 2003 in accordance with generally accepted
government auditing standards.
In summary, CDC*s estimates of the average number of deaths and years of
potential life lost each year due to cigarette smoking were reasonable.
The estimates were based on the increases in deaths from 23 causes that
were linked to cigarette smoking. The linkages of cigarette smoking to
increased mortality due to the included causes, such as lung cancer or
cardiovascular disease, had been well established by the Surgeon General.
CDC used the method generally accepted among epidemiologists for
estimating the increased deaths attributable to cigarette smoking. The
data sources CDC used were the best available and included: the largest
study of smoking behavior and health status available for data on the risk
of death in smokers relative to nonsmokers; the National Health Interview
Survey (NHIS) of over 97,000 persons for data on the prevalence of
smoking; and death certificates compiled from all states for mortality
data. CDC recognized and handled appropriately the limitations in the data
from these sources.
CDC*s estimates of the annual mortality- related productivity losses and
medical expenditures due to cigarette smoking also were reasonable. CDC
estimated productivity losses associated with the years of potential life
lost using assumptions about employment and earnings that are generally
accepted among economists, wellestablished methods for extrapolating from
present earnings to earnings that would be made in the future, and large
federal data sources on earnings. The assumptions that CDC made and the
methods it used to estimate medical expenditures were also generally
accepted among health care economists. CDC relied on the most
comprehensive data available on medical expenditures, the federally
sponsored National Medical Expenditure Survey (NMES) of over 38,000
persons. For both productivity losses and medical expenditures, CDC
recognized and handled appropriately the limitations in the data.
In its comments on a draft of this report, CDC said that this report, in
general, accurately represents the intent, methods, and decision- making
processes of its April 2002 report.
3 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking
Background
The Surgeon General*s first report on smoking and health was published in
1964. This report was the first of many to describe the links between
tobacco smoking and health. Since then, several federal agencies have
issued reports on tobacco and health. 2 In the last four decades, the
Office of the Surgeon General has published dozens of reports on the
health consequences of smoking. CDC*s Office on Smoking and Health
originated as the National Clearinghouse for Smoking and Health in the
Office of the Surgeon General and became part of CDC in 1986. Through this
office, CDC has become a chief source of information on the health
consequences of smoking.
Although the health consequences of cigarette smoking are numerous, CDC*s
April 2002 report provided four estimates* number of deaths, years of
potential life lost, mortality- related productivity losses, and annual
medical expenditures attributable to cigarette smoking. The estimate of
number of deaths is the foundation for both the years of potential life
lost and mortality- related productivity loss estimates. Number of deaths
and years lost are two different ways of measuring mortality attributable
to cigarette smoking, and mortality- related productivity loss is a way of
measuring lives and years of life lost in economic terms. All three of
these estimates are limited to mortality and do not measure morbidity
attributable to cigarette smoking, such as disability, diminished quality
of life, and reduced productivity associated with diseases linked to
cigarette smoking. Unlike the other three estimates, CDC*s estimate of
annual medical expenditures attributable to cigarette smoking includes the
additional medical expenses attributable to cigarette smoking of all
smokers in a given year, not those who died in that year. Thus, CDC*s
estimate is of annual medical expenditures for morbidity attributable to
cigarette smoking. CDC labels as economic costs attributable to cigarette
smoking the sum of its estimates of mortality- related productivity losses
and medical expenditures. However, this summary estimate of economic costs
does not include such costs as time lost in the workplace due to sick
leave and disability.
CDC*s Estimates of Number of Deaths and Years of Potential Life Lost Due
to Cigarette Smoking Were Reasonable
CDC*s estimates of an average of over 440,000 premature deaths and 5.6
million years of potential life lost each year attributable to cigarette
smoking were reasonable. CDC relied on well- established criteria for the
causes of death to include and used
2 See for example, U. S. Department of Health, Education, and Welfare,
National Institutes of Health, National Cancer Institute, and National
Heart, Lung, and Blood Institute, Smoking and Health: A Program to Reduce
the Risk of Diseases in Smokers, Status Report (Bethesda, Md.: December
1978); U. S. Department of Agriculture, Economic Research Service,
Tobacco: Situation and Outlook (Washington, D. C.: April 1995); U. S.
Department of the Treasury, The Economic Costs of Smoking in
the U. S. and the Benefits of Comprehensive Tobacco Legislation
(Washington, D. C.: March 1998); and U. S. Department of Health and Human
Services, National Institutes of Health, National Cancer Institute,
Strategies to Control Tobacco Use In the United States: A Blueprint for
Public Health
Action In the 1990's, Smoking and Tobacco Control Monograph 1 (Bethesda,
Md.: December 1991).
4 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking the
standard method for attributing deaths to cigarette smoking. In addition,
it used the best data sources available and recognized and handled
appropriately the
limitations in the data on which the estimates are based. Total Number of
Deaths Attributable to Cigarette Smoking CDC*s estimate of the average
total number of deaths attributable to cigarette
smoking annually is the sum of deaths in four categories that reflect
differences in how the estimates are obtained: adult deaths from diseases
causally linked to cigarette smoking, infant deaths from conditions
causally linked to maternal cigarette smoking during pregnancy, adult
deaths from diseases causally linked to exposure to secondhand cigarette
smoke, and deaths from residential fires caused by smoking. (See table 1.)
CDC generated the estimates of adult deaths from diseases linked to
cigarette smoking and infant deaths from conditions linked to maternal
cigarette smoking and relied on the estimates of others for secondhand
smoke and fire deaths.
5 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking Table
1: CDC*s Estimates of Average Annual Deaths Attributable to Cigarette
Smoking and Years of Potential Life Lost (1995 to 1999)
Deaths Percentage of total deaths Years of potential
life lost (YPLL) Percentage of total YPLL
Adult deaths from diseases causally linked to cigarette smoking a Cancer
of lip, oral cavity, pharynx 5,137 1.2 85,521 1. 5 Cancer of esophagus
7,893 1.8 120,045 2. 1 Cancer of pancreas 6,480 1.5 98,593 1. 8 Cancer of
larynx 3,127 0.7 48,616 0. 9 Cancer of trachea, lung, bronchus 124,813
28.2 1,869,786 33.3 Cancer of cervix uteri 522 0.1 13,606 0. 2 Cancer of
urinary bladder 4,752 1.1 53,498 1. 0 Cancer of kidney, other urinary
3,035 0.7 46,039 0. 8 Hypertension 6,060 1.4 87,577 1. 6 Ischemic heart
disease 81,976 18.5 1,172,699 20.9 Other heart diseases 29,368 6.6 371,083
6. 6 Cerebrovascular disease 17,445 3.9 280,728 5. 0 Atherosclerosis 2,527
0.6 22,802 0. 4 Aortic aneurysm 9,624 2.2 116,223 2. 1 Other arterial
disease 1,605 0.4 20,894 0. 4 Pneumonia, influenza 15,576 3.5 156,133 2. 8
Bronchitis, emphysema 17,696 4.0 216,376 3. 9 Chronic airways obstruction
64,735 14.6 732,189 13.0
Adult smoker deaths from disease 402,373 91.0 5,512,405 98.1 Infant deaths
from conditions causally linked to maternal cigarette smoking during
pregnancy b Short gestation/ low birthweight 402 0.09 30,556 0. 54
Respiratory distress syndrome 109 0.02 8,198 0.15 Other respiratory*
newborn 117 0.03 8,793 0.16 Sudden infant death syndrome 377 0.09 28,677
0. 51
Infant deaths from maternal smoking 1,007 0.23 76,224 1. 36 Adult deaths
from diseases causally linked to exposure to secondhand cigarette smoke a
Lung cancer 3,000 0.7 - Ischemic
heart disease 35,053 7.9 - Adult
deaths from secondhand smoke 38,053 8.6 - Deaths from residential fires
caused by smoking 966 0.2 27,756 0. 5 Total deaths attributable to
cigarette smoking 442,398 100.0 5,616,385 100.0
Source: CDC, *Annual Smoking- Attributable Mortality, Years of Potential
Life Lost, and Economic Costs * United States, 1995- 1999.* Note:
Individual entries may not sum to totals because of rounding. a For adults
35 years old and older. b For infants 1 year old and younger.
6 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking In
deciding which causes of death to include in its analysis, CDC relied on
the Surgeon General*s determination of the causes of death linked to
cigarette smoking. 3 These determinations are based on extensive reviews
of scientific literature and are
widely regarded as valid. When new data become available, the Surgeon
General*s determination changes accordingly. An alternative method of
estimating deaths attributable to cigarette smoking that does not depend
on decisions about which
causes of death to include has been employed by some researchers. Rather
than including only those deaths due to diseases or conditions that the
Surgeon General considers linked to cigarette smoking, this method
estimates deaths attributable to cigarette smoking regardless of the
specific cause of death. CDC officials told us that they explored this
approach, which yielded an estimate of over 540,000 deaths attributable to
cigarette smoking during 1999, but chose not to use it because it would
have resulted in inflated estimates. 4 The method that CDC used to
estimate adult and infant deaths and that others used
to estimate secondhand smoke deaths is generally accepted among
epidemiologists as appropriate for attributing deaths to cigarette
smoking. 5 Use of this method is necessary because it is not possible to
definitively attribute an individual case of disease to smoking* deaths
from a disease can only be attributed to smoking on a population basis. 6
For example, in the case of lung cancer, not all cigarette smokers develop
lung cancer, and not all people who develop lung cancer are cigarette
smokers. Thus, counting the lung cancer deaths in cigarette smokers and
attributing them to cigarette smoking would not be accurate because some
of those deaths would have occurred even in the absence of cigarette
smoking. Instead, the generally accepted approach attributes to cigarette
smoking only the lung cancer deaths among
3 The Surgeon General*s determinations are based on the application of
standard criteria for establishing causality to information from
comprehensive reviews of the scientific literature. For standard causality
criteria, see A. B. Hill, *The Environment and Disease: Association or
Causation?*
Proceedings of the Royal Society of Medicine, vol. 58, no. 5 (1965): 295-
300. 4 This method was also applied to 1993 data and produced an estimate
of 569,000 deaths attributable to cigarette smoking in 1993. D. M. Burns,
L. Garfinkel, and J. M. Samet, *Introduction, Summary, and Conclusions,*
Changes in Cigarette- Related Disease Risks and Their Implication for
Prevention and
Control, Smoking and Tobacco Control Monograph 8 (Bethesda, Md.: U. S.
Department of Health and Human Services, 1997). 5 See, for example, P.
Bruzzi et al., *Estimating the Population Attributable Risk for Multiple
Risk Factors Using Case- control Data,* American Journal of Epidemiology,
vol. 122, no. 5 (1985): 904- 914.
6 It was not necessary to use this method to estimate deaths from fires
because, unlike deaths from disease, an individual death in a fire can be
definitively attributed to smoking if the fire department determines that
smoking was the cause of the fire.
7 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking
smokers that are in excess of those expected among nonsmokers. Estimates
of deaths attributable to cigarette smoking using this approach are based
on three
components: (1) estimates of the risk for smokers 7 relative to nonsmokers
of dying from each specific disease or condition linked to cigarette
smoking, (2) estimates of the prevalence of cigarette smoking, and (3) the
number of deaths from each disease and condition. The estimate of deaths
attributable to cigarette smoking derived from these three components for
lung cancer, for example, represents the excess number of lung cancer
deaths that occurred because of cigarette smoking.
Adult Deaths from Diseases Causally Linked to Cigarette Smoking
CDC*s estimate of deaths in adult smokers due to diseases causally linked
to cigarette smoking accounted for about 91 percent of its estimate of
total deaths attributable to cigarette smoking. The data sources that CDC
used for each of the three components of the estimate of the number of
deaths attributable to cigarette smoking all had limitations that
potentially could have affected the estimate. However, each was the best
data source available for each particular purpose, and CDC recognized and
dealt appropriately with the limitations so that their effects on the
estimate were minimal.
For the first component of its estimate of adult deaths* estimating the
risk of death for smokers relative to nonsmokers* CDC used the American
Cancer Society*s second Cancer Prevention Study (CPS- II). 8 This study
gathered data on individuals* demographic traits, medical history, and
behavior (such as alcohol use) and reported on the relationship between
cigarette smoking and death. CPS- II, with a sample of about 1.2 million
individuals, had a size advantage over other studies that have similar
information. Smaller samples are not sufficient to produce estimates of
cigarette smoking risks that have margins of error as small as those
obtained using CPS- II.
Although the CPS- II sample was not representative of the national
population* for example, nonwhites were underrepresented* adjustments can
be made for the nonrepresentativeness of the overall sample by estimating
cigarette smoking risks taking account of other factors, such as race. The
size of the CPS- II sample enabled CDC to isolate the increase in risk
that was directly attributable to cigarette smoking and adjust for the
effect that multiple factors can have on a person*s risk of death.
7 Smokers are generally classified as either current smokers or former
smokers, and separate estimates are derived for each group. 8 M. J. Thun
et al., *Trends in Tobacco Smoking and Mortality from Cigarette Use in
Cancer Prevention
Studies I (1959 through 1965) and II (1982 through 1988),* Changes in
Cigarette- Related Disease Risks and Their Implication for Prevention and
Control, Smoking and Tobacco Control Monograph 8 (Bethesda, Md.: U. S.
Department of Health and Human Services, 1997). Study participants
selfreported
information on their medical history, current health status, and a series
of lifestyle factors including smoking behaviors. During the 6- year
follow- up period, deaths among participants were recorded along with the
cause of death as recorded on the death certificate. Death certificates
were obtained for approximately 97 percent of all study participants known
to have died.
8 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking For
example, although the proportion of nonwhites in the sample was less than
the proportion in the general population, the sample still contained
enough nonwhites to
analyze the effect of race on the relative risks. CDC used data from CPS-
II and additional studies to evaluate the importance of race and other
factors* such as education, alcohol use, and diabetes* and concluded that
only age and sex needed to be taken into account in estimating the
relative risks. 9 CPS- II was almost 20 years old at the time of CDC*s
report. It was initiated in 1982
and follow- up of individuals in the study is ongoing. The relative risk
estimates that CDC used were based on follow- up through 1988. Thus, if
relative risks had changed over time, those estimated from CPS- II might
not have been accurate for estimating deaths during 1995 through 1999.
However, CDC and others reviewed studies at different points in time and
determined that the relative risks were likely to have remained stable and
were still applicable.
For the second component of the estimate of deaths attributable to
cigarette smoking* estimates of the prevalence of cigarette smoking among
adults* CDC used the National Health Interview Survey (NHIS), which has
detailed data on cigarette smoking for the years included in CDC*s
analysis. 10 CDC chose to use data that capture cigarette smoking
prevalence during the same years that the deaths of interest occurred.
Using prevalence data from the same years that the deaths occurred
underestimates the number of deaths attributable to cigarette smoking
because, for example, deaths in 1999 are the result of exposure to
cigarette smoke during previous decades and the prevalence of cigarette
smoking declined by 25 percent during the 1990s. In addition, former
smokers in 1999 may have been different from former smokers in the year
that relative risks were estimated* that is, having quit relatively
recently, their risk may resemble that of current smokers more closely
than that of former smokers. CDC officials said that they accepted this
limitation since its result was a lower estimate of the number of deaths
attributable to cigarette smoking.
CDC*s source for the data needed for the last component of the estimate of
deaths attributable to cigarette smoking* the total number of deaths due
to each disease each year* was death certificates. CDC obtained these data
from the National Center for Health Statistics (NCHS), which is the
national repository for information from birth and death certificates.
NCHS has determined that death certificates accurately capture the cause
of death about 97 percent of the time.
9 M. J. Thun, L. F. Apicella, and S. J. Henley, *Smoking vs Other Risk
Factors as the Cause of SmokingAttributable Deaths: Confounding in the
Courtroom,* JAMA, vol. 284, no. 6 (2000): 706- 712 and A. M. Malarcher et
al., *Methodological Issues in Estimating Smoking- Attributable Mortality
in the United States,* American Journal of Epidemiology, vol. 152, no. 6
(2000): 573- 584.
10 The National Health Interview Survey (NHIS) is a nationally
representative survey of health trends in the civilian population. The
survey collects basic health and demographic information every year and
frequently includes questions on smoking. The 1999 NHIS sample consisted
of 37,573 households, which yielded 97, 059 persons in 38, 171 families.
For the adult component, 30, 801 persons 18 years or older were
interviewed.
9 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking Infant
Deaths from Conditions Causally Linked to Maternal Cigarette Smoking
during Pregnancy
Infant deaths from conditions causally linked to maternal cigarette
smoking accounted for less than one half of 1 percent of the total deaths
attributable to cigarette smoking. CDC*s estimate of infant deaths was
based on the same three components as for adults, but the data sources
were necessarily different because, for example, CPS- II was a study of
only adults. CDC*s source of data for the first component* estimates of
the risk of dying for infants whose mothers smoked cigarettes during
pregnancy relative to those whose mothers did not smoke* was a review of
studies of the effects of maternal cigarette smoking. 11 For the second
component, CDC used data compiled from birth certificates and surveys of
new mothers to obtain estimates of cigarette smoking prevalence among
pregnant women. As for adult deaths, the source for the last component of
the estimate was NCHS data on the number of infant deaths each year from
each condition.
Adult Deaths from Diseases Causally Linked to Exposure to Secondhand
Cigarette Smoke
Deaths associated with secondhand cigarette smoke accounted for about 9
percent of CDC*s estimated total number of deaths attributable to
cigarette smoking. CDC obtained its estimates of deaths attributable to
secondhand cigarette smoke from a National Cancer Institute (NCI) report.
12 CDC used the NCI report*s estimate of 3,000 annual lung cancer deaths
associated with secondhand cigarette smoke. 13 The NCI report presented a
range of estimates (35,000- 62,000) for deaths from ischemic heart
disease. CDC used the estimate of 35,000 because it was the lowest of the
range and relied on the same data source CDC used to develop estimates for
adult deaths due to cigarette smoking (CPS- II) and thus would be
consistent with those estimates. 11 N. I. Gavin, C. Wiesen, and C. Layton,
Review and Meta- Analysis of the Evidence on the Impact of
Smoking on Perinatal Conditions Built into SAMMEC II, (Washington, D. C.:
Centers for Disease Control and Prevention, September 2000).
12 U. S. Department of Health and Human Services, National Institutes of
Health, National Cancer Institute, Health Effects of Exposure to
Environmental Tobacco Smoke: The Report of the California Environmental
Protection Agency, Smoking and Tobacco Control Monograph 10 (Bethesda,
Md.: 1999). 13 The NCI report cited the Environmental Protection Agency*s
(EPA) estimate of 3,000 annual lung cancer deaths associated with
secondhand smoke (see U. S. Environmental Protection Agency, Office of
Research and Development, Office of Health and Environmental Assessment,
Respiratory Health Effects of Passive Smoking: Lung Cancer and Other
Disorders (Washington, D. C.: December 1992)). After the report was
published, several tobacco companies filed a lawsuit seeking to have the
report withdrawn, claiming that EPA had violated procedural requirements
in developing the report. In 1998, a district court invalidated certain
chapters of the report, including those on lung cancer. In December
2002, the U. S. Court of Appeals overturned the district court*s decision
and ordered that the suit be dismissed, concluding that the district court
had lacked jurisdiction to hear the suit. (See Flue- Cured Tobacco
Cooperative Stabilization Corporation v. United States EPA, 313 F. 3d 852
(4th Cir. 2002).)
10 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking
Deaths from Residential Fires Caused by Smoking
Deaths from residential fires accounted for less than one half of 1
percent of CDC*s estimated total number of deaths attributable to
cigarette smoking. 14 CDC obtained its estimates of residential fire
deaths from the National Fire Protection Association (NFPA). NFPA national
estimates are of the average annual number of deaths due to fires caused
by smoking and are based on data reported to the U. S. Fire Administration
and NFPA*s annual survey of fire departments. 15 Years of Potential Life
Lost CDC*s estimate of the years of potential life lost was built on the
estimate of number
of deaths attributable to cigarette smoking and provided another
perspective on mortality attributable to cigarette smoking. CDC reported
that, on average, men and women who died from cigarette smoking- related
illness each lost about 13 and 15 years of life, respectively. When
mortality attributable to cigarette smoking is measured in terms of the
number of deaths, each death contributes equally to the total. In
contrast, when mortality is measured in terms of years of potential life
lost, each death contributes to the total depending on how premature the
death was. This measure takes life expectancy into account, and thus death
at a younger age results in a greater loss of potential years of life than
death at an older age. For example, an infant who died as a result of
maternal cigarette smoking would likely have had a greater life expectancy
than an elderly lifetime smoker who died of lung cancer and so would
contribute more years of potential life lost to the total. Thus, although
infant mortality accounts for .23 percent of the total number of deaths,
it accounts for almost six times that percentage (1.36 percent) of the
total number of years lost. In contrast, adult lung cancer mortality
accounts for about the same proportion of both the total number of deaths
and the total number of years lost.
CDC used national life expectancy data published by NCHS to estimate the
expected years of life remaining for those who died from cigarette
smoking. The expected life
14 The National Fire Protection Association (NFPA) estimate that CDC cited
includes deaths from the 1 to 2 percent of fires caused by cigars and
pipes. The estimate does not include deaths from nonresidential and auto-
related fires.
15 The United States Fire Association (USFA) is part of the Federal
Emergency Management Agency. The fire reports sent to USFA*s voluntary
fire reporting system account for about half of the fires each year, and
representation of certain regions of the country and communities may not
be uniform. To address these issues, NFPA supplements USFA*s data with its
own annual survey of a sample of fire
departments. NFPA assumes that fires with unknown or unreported causes
have the same proportional distribution as fires for which the cause is
known and reported.
11 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking span
differs for women and men, by age group, and by year assessed. 16 For
example, in 1995, a 65- year old woman was expected to live another 19
years to age 84 and a
65- year old man was expected to live another 16 years to age 81. A 75-
year old woman in that year was expected to live another 12 years to age
87. In contrast to life expectancies in 1995, a 65- year old woman in 1950
had an expected life span of 80 years. CDC calculated years of potential
life lost by multiplying the estimated remaining life expectancy for each
sex and age group in each year from 1995 through 1999 by the number of
cigarette smoking- attributable deaths in that group in each year. 17 CDC
did not estimate the years lost from secondhand cigarette smoke deaths
because the NCI report from which CDC obtained the estimate of secondhand
smoke deaths did not have sufficient age- specific data. Thus CDC*s
estimate of the total number of potential years of life lost did not
include the lost years associated with about 9 percent of the total
estimated deaths.
CDC*s Estimates of Mortality- Related Productivity Losses and Medical
Expenditures Due to Cigarette Smoking Were Reasonable
CDC*s estimates of $82 billion annually in productivity losses from
mortality attributable to cigarette smoking and $76 billion in additional
medical expenditures for all smokers annually were reasonable. CDC arrived
at these estimates using approaches that were generally accepted among
economists and relied on large federal data sources. CDC recognized and
handled appropriately the limitations in the data on which the estimates
are based.
Mortality- Related Productivity Losses CDC*s estimate of mortality-
related productivity losses built on its estimates of death and years of
potential life lost and measured mortality in economic terms. CDC valued
the years of potential life lost in terms of the productivity lost as a
result of those lost years. CDC used expected future earnings, calculated
in current dollars, to represent mortality- related productivity losses.
An alternative approach to estimating mortality- related productivity
losses attempts to capture the broader impact on productivity of death by
accounting for such factors as time and costs to replace workers and
restore productivity levels. 18 CDC did not take this approach because it
was not widely accepted.
16 Life expectancy also differs by race, with blacks of both sexes and of
all ages generally having lower life expectancies than whites for all
years. CDC did not estimate cigarette- smoking attributable deaths
separately by race and thus did not estimate years of potential life lost
by race. 17 An alternative method for estimating years of potential life
lost is to calculate the years of life
remaining using life expectancy at birth rather than at the age of death.
This method would likely have resulted in a lower estimate of the total
years of productive life lost; however, it is not the method generally
accepted among public health experts. 18 M. A. Koopmanschap, *Estimating
the Indirect Costs of Smoking Using the Friction Cost Method,* ed.
C. Jeanrenaud and N. Soguel, Valuing the Cost of Smoking: Assessment
Methods, Risk Perception and Policy Options (Boston: Kluwer Academic
Publishers, 1999).
12 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking In
estimating mortality- related productivity losses, CDC used estimates of
expected earnings 19 derived from the Bureau of Labor Statistics (BLS), U.
S. Census Bureau, and
other national sources. They take into account both changes in earnings
and the value of money over time. They also include the estimated value of
household work that accounts for the productivity losses among individuals
who do not earn wages for household services. CDC updated the published
earnings estimates using an adjustment factor from BLS so that the
estimates would reflect 1995- 99 earnings. CDC used a single average
estimate of future lifetime earnings for men and women. Because of men*s
higher average earnings and higher incidence of cigarette smokingrelated
death compared to women, the productivity loss estimate was likely to be
lower than if separate average earnings had been used for men and women.
CDC*s estimate of mortality- related productivity losses did not include
the expected lost earnings associated with infant or secondhand cigarette
smoke deaths (about 9 percent of the total deaths). CDC said that it did
not develop an estimate of productivity losses for infants because of a
lack of consensus among economists about the best method for estimating
the potential future earnings of infants. Similarly, the NCI report from
which CDC obtained the estimate of secondhand smoke deaths lacked specific
data on the age at which those deaths occurred* information needed to
estimate expected lost earnings. CDC informed us that it is working on
including these two categories in future estimates of productivity losses
when more reliable data become available.
Medical Expenditures CDC*s estimate of $76 billion annually in additional
medical expenditures attributable to cigarette smokers was not built on
the other three estimates, and its approach to developing this estimate
was different from its approach to the others. CDC examined the use of
health care services and the cost of those services for smokers compared
to nonsmokers independent of the reason* that is, the disease or
condition* for the services. Thus, this estimate is not limited to medical
expenditures associated with a set of diseases and conditions causally
linked to cigarette smoking. CDC*s estimate of total medical expenditures
was the sum of five estimates by type of health care service for adults*
ambulatory care, hospital care, prescription drugs, nursing home, 20 and
other (including home health care, nonprescription drugs, and nondurable
medical equipment)* and an estimate of expenditures for neonatal health
care services. (See table 2.) CDC estimated these expenditures on an
annual basis.
19 CDC*s estimates were drawn from A. C. Haddix et al., eds., Prevention
Effectiveness: A Guide to Decision Analysis and Economic Evaluation (New
York: Oxford University Press, 1996). 20 CDC*s nursing home estimate
accounts for differences between smokers and nonsmokers in the likelihood
of admission to a nursing home but not differences in readmission or
length of stay.
13 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking Table
2: CDC*s Estimates of Annual Mortality- Related Productivity Losses and
Medical Expenditures Attributable to Cigarette Smoking Dollars in millions
Total
Mortality- related productivity losses Men $55,389 Women 26,483
Total mortality- related productivity losses $81,872 Medical expenditures
a Ambulatory care $27,182
Hospital care 17,140 Prescription drugs 6,364 Nursing home 19,383 Other
care 5,419 Neonatal 366
Total medical expenditures $75,854
Source: CDC, *Annual Smoking- Attributable Mortality, Years of Potential
Life Lost, and Economic Costs * United States, 1995- 1999.* a CDC*s
estimate of annual personal medical expenditures for adults attributable
to cigarette smoking was derived using 1998 data obtained from the Health
Care Financing Administration and is in 1998 dollars. Its estimate of
annual neonatal medical expenditures attributable to maternal cigarette
smoking was based on 1996 data and is in 1996 dollars.
The data source that CDC used to determine medical expenditures for
smokers compared to nonsmokers allowed CDC to adjust for many factors*
including certain risk- taking behaviors (e. g., not wearing a seat belt)*
that may affect health care expenditures independent of smoking status. 21
However, although the data source was the most comprehensive available, it
did not include information on alcohol consumption. CDC used data from
another study to assess the importance of drinking alcohol with respect to
expenditures attributable to cigarette smoking and concluded that
adjusting the data for drinking would not have had an appreciable effect
on the results. 22 Expenditures for dental care and mental health care and
certain costs
21 CDC*s primary data source for determining medical expenditures for
smokers compared to nonsmokers was the 1987 National Medical Expenditure
Survey, a population- based survey of over 38, 000 individuals in about
14,000 households.
22 This study assessed utilization of health care services using data from
a nationally representative survey of adults that included information on
utilization of medical care, smoking, and alcohol consumption. CDC based
its conclusion on findings from this study, after an expert panel
determined that these findings were applicable to CDC*s analysis. V. P.
Miller, C. Ernst, and F. Collin, *SmokingAttributable Medical Care Costs
in the USA,* Social Science & Medicine, vol. 48, no. 3 (1999): 375- 391.
14 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking
associated with the care of infants of cigarette smoking mothers were not
included in CDC*s estimate. 23 In addition, certain expenditures for
health services associated with
secondhand cigarette smoke (e. g., care for lung cancer due to secondhand
cigarette smoke in a nonsmoker) and care for nonsmokers injured in
residential fires caused by smoking are not accounted for in the estimate.
By estimating medical expenditures on an annual basis, CDC avoided
limitations associated with the alternative of estimating expenditures
over an individual*s lifetime. The lifetime approach is based on a series
of assumptions and predictions about disease course and duration, survival
rates, patterns of medical care, and impact of disease on employment,
among other factors. Results using a lifetime approach have varied widely*
some studies have concluded that smokers have more medical expenditures
than nonsmokers over their lifetimes and other studies have come to the
opposite conclusion. 24 Changes in the assumptions underlying the annual
approach have less of an effect on the results. CDC*s estimates are
consistent with other annual estimates of medical expenditures published
in the literature. 25 Agency Comments
In its comments on a draft of this report (see enclosure III), CDC said
that this report, in general, accurately represents the intent, methods,
and decision- making processes of its April 2002 report. With respect to
our discussion of the relative risks obtained from CPS- II, CDC noted that
while the overall prevalence of smoking may have decreased since CPS- II,
the relative risks for smokers compared to nonsmokers would not have
decreased because smoking behavior was similar. We have incorporated CDC*s
technical comments as appropriate.
- - - - - 23 CDC*s estimate of costs associated with smoking during
pregnancy includes only neonatal hospital expenditures and excludes costs
of care throughout infancy (for example, those associated with hospital
readmissions in the first year of life) and expenditures associated with
treating secondhand smoke- related conditions arising after birth. The
estimates were based on data from CDC*s Pregnancy Risk Assessment
Monitoring System and 1996 private sector claims data from the Medstat
MarketScan* database.
24 For an example of a study that found greater lifetime expenditures for
smokers, see T. A. Hodgson, *Cigarette Smoking and Lifetime Medical
Expenditures,* Milbank Quarterly, vol. 70, no. 1 (1992): 81125. For an
example of a study that found fewer lifetime expenditures for smokers, see
B. C. Lippiatt, *Measuring Medical Cost and Life Expectancy Impacts of
Changes in Cigarette Sales,* Preventive
Medicine, vol. 19, no. 5 (1990): 515- 532. 25 CDC*s estimate of annual
personal medical expenditures attributable to smoking, $76 billion,
represents approximately 8 percent of total personal medical expenditures,
an estimate within the range of other annual estimates (from about 6 to
about 9 percent). See W. Max, *The Financial Impact
of Smoking on Health- related Costs: A Review of the Literature,* American
Journal of Health Promotion, vol. 15, no. 5 (2001): 321- 333.
15 GAO- 03- 942R CDC*s 2002 Report on Health Consequences of Smoking As
agreed with your office, unless you publicly announce its contents
earlier, we plan no further distribution of this report until 30 days
after its issue date. At that time, we
will send copies to the Director of CDC and other interested parties. We
will also make copies available to others upon request. In addition, this
report will be available at no charge on GAO*s Web site at http:// www.
gao. gov. If you have questions or would like additional information,
please call me at (202) 512- 7119. Another contact and contributors to
this report are listed in enclosure IV.
Sincerely yours, Janet Heinrich Director, Health Care* Public Health
Issues Enclosures
Enclosure I Enclosure I 16 GAO- 03- 942R CDC*s 2002 Report on Health
Consequences of Smoking CDC*s Table Presenting Its Estimates of Cigarette
Smoking- Attributable
Mortality and Years of Potential Life Lost
Note: This table is taken from page 302 of CDC, *Annual Smoking-
Attributable Mortality, Years of Potential Life Lost, and Economic Costs *
United States, 1995- 1999.*
Enclosure II Enclosure II 17 GAO- 03- 942R CDC*s 2002 Report on Health
Consequences of Smoking CDC*s Table Presenting Its Estimates of Smoking-
Attributable MortalityRelated Productivity Losses and Medical Expenditures
Note: This table is taken from page 303 of CDC, *Annual Smoking-
Attributable Mortality, Years of Potential Life Lost, and Economic Costs *
United States, 1995- 1999.*
Enclosure III Enclosure III 18 GAO- 03- 942R CDC*s 2002 Report on Health
Consequences of Smoking
Comments from the Centers for Disease Control and Prevention
Enclosure IV Enclosure IV 19 GAO- 03- 942R CDC*s 2002 Report on Health
Consequences of Smoking
GAO Contact and Staff Acknowledgments
GAO Contact Michele Orza, (202) 512- 6970 Acknowledgments The following
staff members made important contributions to this work: Angela Choy, Chad
Davenport, Maria Hewitt, Donald Keller, and Nkeruka Okonmah.
(290254)
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