Current Trends
Economic Burden of Spina Bifida -- United States, 1980-1990
Spina bifida is one of the most common and disabling birth defects
and
results in varying degrees of paralysis from permanent damage to
the
spinal cord and spinal nerves. Based on rates from CDC's Birth
Defects
Monitoring Program (1), from 1980 through 1987, an estimated 13,600
infants born in the United States had spina bifida without
anencephaly.
Of these, approximately 3800 have died as a result of their
defects.
Although the estimated rate of infants born with spina bifida has
decreased from 1980 (5.2/10,000 live births) through 1987
(4.3/10,000
live births), a substantial number of infants survive into
childhood
each year; an estimated 9800 children born with spina bifida
between
1980 and 1987 were alive in 1987. Even if the rate of infants born
with
spina bifida continues to decline at the same rate from 1988
through
1990, the number of surviving children born with spina bifida since
1980 will be approximately 13,000 by the end of 1990 (Figure 1).
Spina bifida-associated damage to the spinal cord produces severe
disabilities requiring extensive medical and surgical care. In the
United States, infants with spina bifida routinely receive vigorous
medical therapy and undergo repeated surgical procedures to survive
and
to reach their maximum functional capacity. At birth, the spinal
defect
is closed surgically. Because the severe spinal nerve damage
impairs
lower extremity motor functions, many children are confined to
wheelchairs, although others can walk with the assistance of
braces.
Almost all require multiple orthopedic surgical operations. Bladder
and
sphincter control are also affected, causing chronic urinary tract
infections. Hydrocephalus is usually associated with spina bifida
and
requires insertion of a shunt to relieve intracranial pressure and
to
prevent brain damage. These shunts often require multiple revisions
and
replacement during childhood. Throughout childhood, adolescence,
and
adulthood, the management of the Arnold-Chiari malformation (a
malformation of the cerebellum and medulla oblongata) associated
with
spina bifida and of urologic problems often requires more surgical
procedures.
National estimates of the total cost to society for medical care,
education, and lost productivity are difficult to calculate for
several
reasons. The current prevalence of spina bifida in older cohorts is
unknown. Also, data on the educational and employment patterns of
persons with spina bifida are unavailable, as are valid national
data
on costs of medical and surgical treatment and other therapies. CDC
has
estimated the direct medical costs by using average annual
age-specific
charges* for medical and surgical procedures for open spina bifida
from
North Carolina (2). These cost estimates were applied to the
estimated
cohorts of surviving children born since 1980 to arrive at the
projected annual costs (in 1985 dollars, not discounted) from 1980
through 1990 (Figure 2). If the costs for all children born with
spina
bifida from 1980 through 1990 are discounted by 5%, the resulting
present value (using 1985 as the base year) exceeds $775 million.
Reported by: Birth Defects and Genetic Diseases Br and
Developmental
Disabilities Br, Div of Birth Defects and Developmental
Disabilities,
Center for Environmental Health and Injury Control, CDC.
Editorial Note
Editorial Note: Spina bifida is a major contributor to morbidity
and
mortality in childhood. The rate of spina bifida in the United
States
has been declining and now is among the lowest in the world.
Nevertheless, each year approximately 1500 infants are born in the
United States with spina bifida; more than 1000 of these survive
into
childhood (Figure 1). The highest estimated U.S. rates of spina
bifida--about 10/ 10,000 live births--are in Appalachia (3).
Annual medical and surgical care costs in the United States for all
persons with spina bifida probably exceed $200 million. In 1990,
the
average annual cost for medical and surgical care for all surviving
children born since 1980 will approach $100 million (Figure 2).
However, this estimate excludes costs generated since 1980 for all
persons born with spina bifida before 1980. These cohorts are as
large
as those born after 1980; therefore, it is likely that their costs
would equal or exceed those of the post-1980 cohorts. For a person
with
typical severe spina bifida, estimated lifetime costs--including
direct
costs such as medical and surgical care, long-term care,
disability,
and education, and indirect costs such as survivor productivity
effects
and loss of parental income--are $250,000 (in 1985 dollars
discounted
by 5%) (2).
The descriptive epidemiology of spina bifida and anencephaly has
suggested hypotheses regarding environmental (nongenetic) factors
as
important contributors to causing most of these defects. In the
last 50
years, epidemics of spina bifida have occurred in Boston;
Rochester,
New York; Dublin, Ireland; and northern People's Republic of China
(4,5). Rates of spina bifida vary widely among countries and by
geographical regions within countries. The current highest reported
rate is 37/10,000 births in rural northern People's Republic of
China
(5), about nine times the total U.S. rate of 4.3/10,000 live births
in
1987. Low socioeconomic status has been strongly associated with
risk
for these defects in many populations. The causes of spina bifida
must
be identified to design effective primary prevention. These
epidemiologic findings suggest that such identification may be
possible.
Nutritional status has been widely studied as a risk factor for
spina
bifida in the last decade. In particular, periconceptional vitamin
supplementation in women who previously had had an affected infant
was
studied in a nonrandomized clinical trial and reported in 1981 to
be
protective (6). However, 95% of all infants with spina bifida are
born
to women who have never had an affected infant. A CDC case-control
study of a large group of these women showed that those who
reported
using multivitamin supplementation during the periconceptional
period
had a 50% reduction in the incidence of spina bifida in their
children
(7,8). It cannot yet be determined whether the apparent protective
effect associated with multivitamins results directly from
multivitamin
use or from other characteristics of women who use vitamins.
Therefore,
the evidence accumulated to date does not support recommendation of
a
national policy for treating all women at risk for pregnancy with
multivitamins. Well-designed randomized clinical trials would be a
means by which to examine this issue further.
References
CDC. Congenital malformations surveillance report: January
1982-December 1985. Atlanta: US Department of Health and Human
Services, Public Health Service, 1988.
2.Lipscomb J. Human capital, willingness-to-pay and
cost-effectiveness
analyses of screening for birth defects in North Carolina (Working
paper). Durham, North Carolina: Duke University, Institute of
Policy
Sciences and Public Affairs, 1986.
3.Greenberg F, James LM, Oakley GP Jr. Estimates of birth
prevalence
rates of spina bifida in the United States from computer-generated
maps. Am J Obstet Gynecol 1983;145:570-3.
4.Elwood JM, Elwood JH. Epidemiology of anencephalus and spina
bifida.
Oxford: Oxford University Press, 1980.
5.Lian ZH, Yang HY, Li Z. Neural tube defects in Beijing-Tianjin
area
of China: urban rural distribution and some other epidemiological
characteristics. J Epidemiol Community Health 1987;41:259-62.
6.Smithells RW, Nevin NC, Seller MJ, et al. Further experience of
vitamin supplementation for prevention of neural tube defect
recurrences. Lancet 1983;1:1027-31.
7.Mulinare J, Cordero JF, Erickson JD, Berry RJ. Periconceptional
use
of multivitamins and the occurrence of neural tube defects. JAMA
1988;260:3141-5.
8.CDC. Periconceptional use of multivitamins and the occurrence of
anencephaly and spina bifida. MMWR 1988;37:727-30.
*While charges are generally not the best measure of the
incremental,
or marginal, resource cost of medical care, they are the
appropriate
means of measuring the financial burden of care on parents, private
insurers, and government.
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