Current Trends
Sudden Infant Death Syndrome as a Cause of Premature Mortality
United States, 1984 and 1985
Of the 10 leading causes of years of potential life lost before
age 65
(YPLL), three occur primarily in the first year of life: congenital
anomalies ranked fifth, prematurity ranked sixth, and sudden infant
death syndrome (SIDS) ranked seventh (1). The previous report on
SIDS
included preliminary estimates of 1984-1986 YPLL associated with
SIDS
(2). This report, based on final mortality data, compares estimates
of
SIDS-associated YPLL by race and sex for 1984 and 1985 with those
for
1980-1983.
To estimate YPLL for SIDS as reported in Table V (3), national
death
certificate data were compiled from the National Center for Health
Statistics (NCHS), CDC, national mortality computer tapes. Deaths
were
attributed to SIDS if both the underlying cause of death was
classified
as category 798.0 (according to the International Classification of
Diseases, Ninth Revision (ICD-9)) and the death occurred during
infancy
(less than 1 year of age). SIDS was divided into groups by race*
and
sex of infant. YPLL was calculated by averaging the age at death
for
each subgroup** for this study period. Because trends in YPLL from
infant deaths are affected by the annual number of live births, the
average annual SIDS-attributable YPLL per 1000 live births was also
calculated.
In 1984, 5245 SIDS cases were reported, accounting for 339,517
YPLL
(Table 1). Similarly, in 1985, 5315 SIDS deaths were reported,
accounting for 344,114 YPLL. In both years, SIDS was the seventh
leading cause of YPLL (1).
Males accounted for 61% of SIDS-attributable YPLL for 1984-1985
(Table
1), and white males had the highest proportion (44%) of
SIDS-attributable YPLL for this period. Seventy percent of
SIDS-attributable YPLL occurred among whites, 26% among blacks, and
3%
among Native American and other races. The average annual YPLL
rates
per 1000 live births were highest for blacks and Native Americans
(Table 2). However, rates for all racial/sex groups except white
males
and others (not including Native Americans) decreased slightly from
those for 1980-1983.
Reported by: Pregnancy Epidemiology Br and Research and Statistics
Br,
Div of Reproductive Health, Center for Health Promotion and
Education,
CDC.
Editorial Note
Editorial Note: To decrease or eliminate misdiagnoses, the term
"SIDS" was defined by the Second International Conference on Causes
of
Sudden Death in Infants held in Seattle, Washington, in 1969 (4).
Formerly called a "crib death" or "cot death," SIDS is now defined
as
"the sudden death of any infant or young child which is unexpected
by
history, and in which case a thorough postmortem examination fails
to
demonstrate an adequate cause of death" (4). Confirmation of SIDS
requires a thorough history, a postmortem examination, and a death
scene investigation (5,6). Although a postmortem examination is
needed
to diagnose SIDS, the percentage of autopsy- confirmed diagnoses
varies
by state. Data from the NCHS mortality tapes from 1980 to 1985 show
that the autopsy rate has increased overall during this time. In
1980,
the SIDS autopsy rate by state ranged from 10% to 100% (median:
82%).
By 1984, it had increased to 25%-100% (median: 92%), and by 1985,
to
47%-100% (median: 93%). Appropriate investigation and diagnosis
of
SIDS may assist in allocating health-care resources for prevention
programs.
Although the continuing high male:female ratio of YPLL is
consistent
with findings of most epidemiologic studies of SIDS (7,8), the
slight
increases in YPLL rates among white males since 1980-1983 should be
monitored to determine a possible emerging trend. These findings
underscore the usefulness of evaluating trends in YPLL that are
based
on the annual number of live births in any given group.
Despite a decline in YPLL per 1000 live births for blacks, racial
differences in SIDS-attributable YPLL remain a concern. The
1984-1985
rate of SIDS-attributable YPLL for blacks was 1.9 times, and for
Native
Americans, 1.7 times that for whites. This discrepancy was also
demonstrated in a study of birthweight-specific infant mortality
among
Native Americans. Native Americans had a SIDS postneonatal
mortality
risk 3.5 times that of whites (9). These data suggest a need for
further investigation of race and gender differences for SIDS.
References
CDC. Changes in premature mortality--United States, 1979-1986.
MMWR
1988;37:47-8.
CDC. Premature mortality due to sudden infant death
syndrome--United
States, 1980-1986. MMWR 1987;36:236-8.
CDC. Introduction to Table V: premature deaths, monthly
mortality,
and monthly physician contacts--United States. MMWR
1982;31:109-10,117.
Beckwith JB. Discussion of terminology and definition of sudden
infant death syndrome. In: Bergman AB, Beckwith JB, Ray CG, eds.
Sudden
infant death syndrome. Proceedings of the Second International
Conference on Causes of Sudden Death in Infants. Seattle,
Washington:
University of Washington Press, 1970.
Jones AM, Weston JT. The examination of the sudden infant death
syndrome infant: investigative and autopsy protocols. J Forensic
Sci
1976;21:833-41.
Lewman LV. Oregon's model system: a statewide approach. Pediatr
Ann
1974;Nov:44-54.
Beckwith JB. The sudden infant death syndrome. Rockville,
Maryland:
US Department of Health, Education, and Welfare, Public Health
Service,
Health Services Administration, 1976; DHEW publication no.
(HSA)76-5137.
Peterson DR, van Belle G, Chinn NM. Epidemiologic comparisons of
the
sudden infant death syndrome with other major components of infant
mortality. Am J Epidemiol 1979;110: 699-707.
Vanlandingham MJ, Buehler JW, Hogue CJR, Strauss LT.
Birthweight-specific infant mortality for Native Americans compared
with whites, six states, 1980. Am J Public Health 1988; 78:499-503.
*This is the first report that divides YPLL for persons of other
races
into Native Americans (American Indians, Aleuts, and Eskimos) and
others (Chinese, Japanese, Hawaiian, Filipino, and others).
**YPLL = T (65-(A/365.25)), where T = total number of infant deaths
for
subgroup (year, race, and sex) and A = average age at death in days
for
that subgroup.
Disclaimer
All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.
**Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.
