Series 2, No. 166 [ Page 5
As a result of the 286 county
category shifts, the four metropolitan
levels of the 2013 NCHS scheme have
more counties than the corresponding
levels of the 2006 scheme, and the two
nonmetropolitan levels have fewer
(Table 2). The largest differences in the
category counts occur for the medium
metro level (373 counties in the 2013
scheme compared with 332 in the 2006
scheme) and the micropolitan level (641
counties in the 2013 scheme compared
with 694 in the 2006 scheme). The
percentage of the U.S. population in
each of the six levels was similar for the
two schemes.
Health Measures by
Urbanization Level
The 2013 and 2006 NCHS
Urban–Rural Classification Schemes for
Counties were merged with National
Vital Statistics System (NVSS) mortality
records and National Health Interview
Survey (NHIS) data using restricted-use
files to illustrate the ability of the
NCHS scheme to identify health
differences across urbanization levels.
Sex-specific death rates for selected age
groups and causes of death during
2008–2010 were examined across the
urbanization levels (Tables 5 and 6).
Estimates of a health status measure
(report of fair or poor health), a health
access measure (lack of health
insurance), and a health-related behavior
(current cigarette smoking) were
examined using data from the
2010–2012 NHIS (Table 7). NHIS
collects data on a broad range of health
topics through personal household
interviews. For all of the health
measures, a test of linear trend across
the urbanization levels was performed.
For all but 4 of the 10 health measures
(death rates for adults aged 65 and over,
motor vehicle and cerebrovascular death
rates, and percentage who currently
smoke), the large central metro category
value was higher than the large fringe
metro category value, so the large
central metro category was omitted from
the trend analysis. For each of the health
measures, the statistical significance of
pairwise comparisons of the urban–rural
categories was assessed using a z test
and a p value of 0.05 without adjusting
for multiple comparisons. Note that
while the large central metro category
was omitted from some of the trend
analyses, it was included in all of the
pairwise comparisons.
For all of the health measures
examined, the estimates for each
urbanization level under the 2013 and
2006 NCHS schemes were identical or
very similar. Therefore, statements about
the patterns observed will be restricted
to the 2013 estimates.
Infant mortality—Infant mortality rates
during 2008-2010 increased for both
sexes with decreasing urbanization from
a low in large fringe metro counties. For
both males and females, infant mortality
was 11%–23% lower in fringe counties
than in any of the other urbanization
levels.
Mortality for children and young
adults—For males aged 1–24 years, the
2008–2010 age-adjusted death rate was
lowest in large fringe metro counties
and highest in noncore counties (the
most rural counties). Comparing rates
for males in fringe counties with those
in the other urbanization levels shows
that the rates in large central, medium,
and small metro counties were all
moderately higher (5%–8%), the rate in
micropolitan counties was 22% higher,
and the rate in noncore counties was
57% higher. For females, the 2008–2010
age-adjusted death rates in large central
and large fringe metro counties were
similarly low, those in medium and
small metro counties were about 10%
higher, and those in micropolitan and
noncore counties were 34% and 68%
higher, respectively.
Mortality for adults aged 25–64—In
2008–2010, the death rate for adults
aged 25–64 was lowest in fringe
counties of large metro areas and
increased steadily as counties become
more rural. The age-adjusted death rate
in the noncore counties was 44%
higher for males and 47% higher for
females. For both males and females in
this age group, the death rate was higher
in large central metro counties than in
large fringe metro counties.
Mortality for adults aged 65 and
over—Among adults aged 65 and over,
the 2008–2010 age-adjusted death rate
was lowest in large central metro
counties and increased with decreasing
urbanization. For both sexes, the death
rate in noncore counties was 14% higher
than the rate in large central metro
counties.
Homicide—The 2008–2010 age-
adjusted homicide rate for males in
large central metro counties was about
one and one-half times the rate in
medium metro counties and more than
double the rate in any of the other
urbanization levels. There was no linear
trend across the urbanization levels. For
females, the homicide rate was highest
in large central metro and noncore
counties. Homicide rates for females are
much lower than those for males, and
the relative differences among the rates
in the urbanization levels were smaller
than those among males.
Motor vehicle accident mortality—
Death rates for motor vehicle accidents
increase markedly as counties become
less urban. For males, the 2008–2010
age-adjusted motor vehicle death rates
in the most rural noncore counties were
nearly three times as high as those in
large central metro counties; for
females, they were more than three
times as high.
Cerebrovascular disease mortality—
For males, the 2008–2010 age-adjusted
cerebrovascular disease death rate was
lowest in large fringe metro counties
and increased with decreasing
urbanization level (the rates in
micropolitan and noncore counties were
about 23% higher than in large fringe
counties). For females, the age-adjusted
cerebrovascular disease death rates also
increased with decreasing urbanization
level, but the rate was similarly lowest
in the large central and large fringe
metro counties. The rate in noncore
counties was about 29% higher than the
rates in the large central and fringe
counties.
Health status—The percentage of NHIS
respondents aged 18–64 reporting fair or
poor health (out of a five-level scale of
excellent, very good, good, fair, or poor)