NCHS Data Brief ■ No. 300 ■ February 2018

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Center for Health Statistics

Differences Between Rural and Urban Areas in 

Mortality Rates for the Leading Causes of Infant Death: 

United States, 2013–2015

Danielle M. Ely, Ph.D., and Donna L. Hoyert, Ph.D.

Key findings 

Data from the National 

Vital Statistics System

● Infant, neonatal, and

postneonatal mortality rates

were higher in rural counties

than in large urban counties.

● Infant mortality rates for

congenital malformations,

sudden infant death syndrome,

and unintentional injuries were

highest in rural counties and

lowest in large urban counties;

rural counties had the lowest

infant mortality rates for low

birthweight and maternal

complications.

● The neonatal mortality rate

for congenital malformations 

was highest in rural counties 

(105.12 per 100,000 live 

births), followed by small and 

medium urban counties (94.07) 

and large urban counties 

(77.03).

● Postneonatal mortality

rates for sudden infant

death syndrome, congenital

malformations, and

unintentional injuries were

highest in rural counties and

lowest in large urban counties.

The leading causes of infant death vary by age at death but were consistent 

from 2005 to 2015 (1–6). Previous research shows higher infant mortality 

rates in rural counties compared with urban counties and differences in cause 

of death for individuals aged 1 year and over by urbanization level (4,5,7,8). 

No research, however, has examined if mortality rates from the leading causes 

of infant death differ by urbanization level. This report describes the mortality 

rates for the five leading causes of infant, neonatal, and postneonatal death 

in the United States across rural, small and medium urban, and large urban 

counties defined by maternal residence, as reported on the birth certificate for 

combined years 2013–2015.

Keywords: infant mortality • cause of death • National Vital Statistics System

Rural counties had higher infant, neonatal, and postneonatal 

mortality rates than large urban counties. 

Figure 1. Total infant, neonatal, and postneonatal mortality rates, by urbanization level:

United States, 2013–2015

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

Significantly different from rural counties (p < 0.05). 2

Significantly different from small and medium urban counties (p < 0.05).

NOTES: County designation is based on mother’s county of residence as reported on the birth certificate. 

County classification is based on the 2013 NCHS Urban–Rural Classification Scheme for Counties. 

Access data table for Figure 1 at: https://www.cdc.gov/nchs/data/databriefs/db300_table.pdf#1.

SOURCE: NCHS, National Vital Statistics System, linked birth/infant death data set.
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● In 2013–2015, the infant mortality rate was highest in rural counties (6.69 infant deaths per 

1,000 live births), followed by small and medium urban counties (6.29) and large urban 

counties (5.49) (Figure 1). 

● Neonatal mortality rates were higher in rural counties (4.21 neonatal deaths per 1,000 live 

births) and small and medium urban counties (4.15) than in large urban counties (3.83); 

there were no significant differences between rural counties and small and medium urban 

counties in the neonatal mortality rate.

● Postneonatal mortality rates were highest in rural counties (2.48 postneonatal deaths per 

1,000 live births), followed by small and medium urban (2.14) and large urban (1.66) 

counties.

The mortality rate for the five leading causes of infant death varied by 

urbanization level. 

● In 2013–2015, the infant mortality rate for congenital malformations, sudden infant death 

syndrome, and unintentional injuries was highest in rural counties, lower in small and 

medium urban counties, and lowest in large urban counties (Figure 2). 

● Rural counties had a lower infant mortality rate for low birthweight (95.99 infant deaths per 

100,000 live births), compared with small and medium urban counties (105.70) and large 

urban counties (106.46).

Figure 2. Infant mortality rates for the five leading causes of infant death, by urbanization level: United States, 

2013–2015 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

Significantly different from rural counties (p < 0.05). 2

Significantly different from small and medium urban counties (p < 0.05).

NOTES: County designation is based on mother’s county of residence as reported on the birth certificate. County classification is based on the 2013 NCHS 

Urban–Rural Classification Scheme for Counties. Access data table for Figure 2 at: https://www.cdc.gov/nchs/data/databriefs/db300_table.pdf#2.

SOURCE: NCHS, National Vital Statistics System, linked birth/infant death data set.
NCHS Data Brief ■ No. 300 ■ February 2018

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● Rural counties also had a lower infant mortality rate for maternal complications (32.78) 

compared with small and medium urban counties (41.68) and large urban counties (40.02). 

Rural counties had lower neonatal mortality rates for two of the five leading 

causes of neonatal death compared with small and medium urban and 

large urban counties. 

● In 2013–2015, rural counties had a lower neonatal mortality rate for low birthweight (93.21 

neonatal deaths per 100,000 live births) compared with small and medium urban and large 

urban counties (103.47 and 103.96, respectively) (Figure 3). 

● Rural counties also had a lower neonatal mortality rate for maternal complications (32.72) 

than small and medium urban and large urban counties (41.45 and 39.72, respectively).

● In contrast, the neonatal mortality rate for congenital malformations was highest in rural 

counties (105.12), followed by small and medium urban (94.07) and large urban (77.03) 

counties.

● There were no significant differences by urbanization level in neonatal mortality rates for 

deaths from placenta, cord, and membrane complications or bacterial sepsis of the newborn.

Figure 3. Neonatal mortality rates for the five leading causes of neonatal death, by urbanization level: United States, 

2013–2015 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

Significantly different from rural counties (p < 0.05). 2

Significantly different from small and medium urban counties (p < 0.05).

NOTES: Neonatal deaths are deaths of infants aged 0–27 days. County designation is based on mother’s county of residence as reported on the birth certificate. 

County classification is based on the 2013 NCHS Urban–Rural Classification Scheme for Counties. Access data table for Figure 3 at: 

https://www.cdc.gov/nchs/data/databriefs/db300_table.pdf#3.

SOURCE: NCHS, National Vital Statistics System, linked birth/infant death data set.
NCHS Data Brief ■ No. 300 ■ February 2018

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The postneonatal mortality rate was higher in rural counties than in large 

urban counties for four of the five leading causes of postneonatal death. 

● In 2013–2015, the postneonatal mortality rate for sudden infant death syndrome, congenital 

malformations, and unintentional injuries was highest in rural counties, followed by small 

and medium urban and large urban counties (Figure 4). 

● The postneonatal mortality rate for homicide was higher in rural counties (8.27 infant deaths 

per 100,000 live births) than in large urban counties (4.98); the postneonatal mortality rate 

for homicide in small and medium urban counties (7.33) was not significantly different from 

rural or large urban counties.

● The postneonatal mortality rate for diseases of the circulatory system was higher in small 

and medium urban counties (10.15) than in large urban counties (7.98); the postneonatal 

mortality rate for diseases of the circulatory system in rural counties (8.58) was not 

significantly different from small and medium urban or large urban counties.

Figure 4. Postneonatal mortality rates for the five leading causes of postneonatal death, by urbanization level:

United States, 2013–2015 Infant deaths per 100,000 live births

Five leading causes of postneonatal death

 

 

 

 

 

 

 

55.00 

 

 

 

 

 

1

32.78

7.33 

 

 

 

 

 

 

 

 

 

 

 

 

1

Significantly different from rural counties (p < 0.05). 2

Significantly different from small and medium urban counties (p < 0.05).

NOTES: Postneonatal deaths are deaths of infants aged 28 days–11 months. County designation is based on mother’s county of residence as reported on the 

birth certificate. County classification is based on the 2013 NCHS Urban–Rural Classification Scheme for Counties. Access data table for Figure 4 at:

https://www.cdc.gov/nchs/data/databriefs/db300_table.pdf#4.

SOURCE: NCHS, National Vital Statistics System, linked birth/infant death data set.
NCHS Data Brief ■ No. 300 ■ February 2018

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Summary

Previous research indicates the importance of maternal conditions during pregnancy for birth 

outcomes and later health conditions (9–13). Specifically, evidence shows that poor social 

conditions (e.g., poverty), maternal health behaviors during pregnancy (e.g., smoking), and 

disadvantaged community environments (e.g., less access to health care services) impact infant 

health and infant mortality (9,10,12,13). By using maternal residence provided on the birth 

certificate to examine infant causes of death by urbanization level, it is possible to capture 

differences in mortality rates that could be related to differences in conditions during pregnancy. 

In 2013–2015, total infant and postneonatal mortality rates were highest in rural counties, 

followed by small and medium urban counties; the lowest rates were in large urban counties. 

Rural and small and medium urban counties had higher neonatal mortality rates compared with 

large urban counties. Of the three urbanization areas, rural counties had the highest neonatal 

mortality rates for congenital malformations, followed by small and medium urban counties; 

large urban counties had the lowest. Rural counties had higher postneonatal mortality rates 

compared with large urban counties for sudden infant death syndrome, congenital malformations, 

unintentional injuries, and homicide. Postneonatal mortality rates in small and medium urban 

counties for sudden infant death syndrome, congenital malformations, and unintentional injuries 

were lower than the rates in rural counties and higher than the rates in large urban counties. 

Neonatal mortality rates for low birthweight and maternal complications of pregnancy were 

lower in rural counties than in small and medium urban and large urban counties. These results 

are consistent with other research showing differences between rural and urban places in cause of 

death and mortality rates for individuals aged 1 year and over (5,8). 

These findings add to general knowledge on infant mortality and expand insight into geographic 

differences in risk of infant death by specific causes of death.

Definitions

Cause-of-death classification: Medical information—including injury diagnoses and external 

causes of injury—is entered on death certificates filed in the United States and classified and 

coded in accordance with the International Statistical Classification of Diseases and Related 

Health Problems, Tenth Revision (ICD–10) (7). Corresponding abbreviations of infant causeof-death categories and ICD–10 codes presented in this report are:

● Diseases of the circulatory system (I00–I99)

● Maternal complications: Newborn affected by maternal complications of pregnancy (P01)

● Placenta, cord and membrane complications: Newborn affected by complications of

placenta, cord and membranes (P02)

● Low birthweight: Disorders related to short gestation and low birthweight, not elsewhere

classified (P07)

● Bacterial sepsis of the newborn (P36)
NCHS Data Brief ■ No. 300 ■ February 2018

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● Congenital malformations: Congenital malformations, deformations and chromosomal 

abnormalities (Q00–Q99)

● Sudden infant death syndrome (R95)

● Unintentional injuries: Accidents (unintentional injuries [V01–X59])

● Homicide: Assault (homicide [*U01, X85–Y09])

Infant mortality rate: Number of infant (under age 1 year) deaths per 1,000 live births.

Leading causes of death: Ranked according to the number of deaths assigned to rankable causes (3).

Neonatal deaths: Deaths of infants aged 0–27 days. 

Postneonatal deaths: Deaths of infants aged 28 days–11 months. 

Urbanization level: County classification as urban or rural is based on the county of maternal 

residence provided on the birth certificate (8). Counties were classified according to their 

metropolitan status using the NCHS (National Center for Health Statistics) Urban–Rural 

Classification Scheme for Counties (available from: https://www.cdc.gov/nchs/data_access/

urban_rural.htm), by merging the county of maternal residence’s geographic federal information 

processing standard (FIPS) codes with county-level FIPS codes from the 2013 NCHS 

Urban–Rural Classification Scheme for Counties data set. Metropolitan counties include large 

central counties, the fringes of large counties (suburbs), medium counties, and small counties. 

Nonmetropolitan counties include micropolitan statistical areas and noncore areas, including open 

countryside, rural towns (populations of less than 2,500), and areas with populations of 2,500–

49,999 that are not part of larger labor market areas (metropolitan areas). Due to the variation in 

urban county sizes, two sizes of urban counties were created—large (large central and the fringes 

of large cities) and small and medium urban (which includes medium and small cities)—for 

comparative purposes. In this report, rural counties include micropolitan and noncore counties.

Data sources and methods

This report contains data from the period linked birth/infant death data set, which is part of the 

National Vital Statistics System (14). The period linked birth/infant death data set includes all 

infant deaths under age 1 year reported on death certificates and all live births reported from birth 

certificates (14). The period linked birth/infant death data set is the primary data set for analyzing 

infant mortality trends and patterns in the United States and is the only source for examining race 

and Hispanic-origin infant mortality and other factors related to birth (14). Linked birth/infant 

death data sets are available from: https://www.cdc.gov/nchs/data_access/vitalstatsonline.htm. 

The five leading causes of infant, neonatal, and postneonatal death are identified from the 

2013–2015 mortality data (1,3). The five leading causes of infant death (congenital 

malformations, low birthweight, sudden infant death syndrome, maternal complications, and 

unintentional injuries), neonatal death (low birthweight; congenital malformations; maternal 

complications; placenta, cord and membrane complications; and bacterial sepsis of the newborn), 

and postneonatal death (sudden infant death syndrome, congenital malformations, unintentional
NCHS Data Brief ■ No. 300 ■ February 2018

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injuries, diseases of the circulatory system, and homicide) were consistent from 2013 to 2015 

(1,3). 

Data from the NCHS Urban–Rural Classification Scheme for Counties provide geographic FIPS 

codes and urban–rural classification scheme information for all counties in the United States. 

The NCHS county classification scheme data are available from: https://www.cdc.gov/nchs/data_

access/urban_rural.htm.

References to rates indicate that differences are statistically significant at the 0.05 level (15). 

About the authors

Danielle M. Ely and Donna L. Hoyert are with the National Center for Health Statistics, Division 

of Vital Statistics.

References

1. Heron M. Deaths: Leading causes for 2014. National Vital Statistics Reports; vol 65 no 5. 

Hyattsville, MD: National Center for Health Statistics. 2016.

2. Heron M, Tejada-Vera B. Deaths: Leading causes for 2005. National Vital Statistics Reports; 

vol 58 no 8. Hyattsville, MD: National Center for Health Statistics. 2009.

3. Heron M. Deaths: Leading causes for 2015. National Vital Statistics Reports; vol 66 no 5. 

Hyattsville, MD: National Center for Health Statistics. 2017.

4. Ely DM, Driscoll AK, Mathews TJ. Infant mortality rates in rural and urban areas in the 

United States, 2014. NCHS Data Brief, no 285. Hyattsville, MD: National Center for Health 

Statistics. 2017.

5. Meit M, Knudson A, Gilbert T, Yu ATC, Tanenbaum E, Ormson E, et al. The 2014 update of 

the rural-urban chartbook. Rural Health Reform Policy Research Center. 2014.

6. CDC. National Center for Health Statistics, linked birth/infant death records 1995–2015, as 

compiled from data provided by the 57 vital statistics jurisdictions through the Vital Statistics 

Cooperative Program, on CDC WONDER Online Database. Available from: 

https://wonder.cdc.gov.

7. WHO. International statistical classification of diseases and related health problems, tenth 

revision (ICD–10). 2008 ed. Geneva, Switzerland. 2009.

8. Ingram DD, Franco SJ. NCHS urban–rural classification scheme for counties. National 

Center for Health Statistics. Vital Health Stat 2(154). 2012.

9. Hayward MD, Gorman BK. The long arm of childhood: The influence of early-life social 

conditions on men’s mortality. Demography 41(1):87–107. 2004.
NCHS Data Brief ■ No. 300 ■ February 2018

10. Sparks PJ, McLaughlin DK, Stokes CS. Differential neonatal and 

postneonatal infant mortality rates across US counties: The role of 

socioeconomic conditions and rurality. J Rural Health 25(4):332–41. 2009.

11. National Institute of Child Health and Human Development. Are there 

ways to reduce the risk of infant mortality? Available from: https://www.

nichd.nih.gov/health/topics/infant-mortality/topicinfo/Pages/reduce-risk.aspx.

12. Healthy People 2020. Maternal, infant, and child health. Available from: 

https://www.healthypeople.gov/2020/topics-objectives/topic/maternal-infantand-child-health.

13. Huynh M, Parker JD, Harper S, Pamuk E, Schoendorf KC. Contextual 

effect of income inequality on birth outcomes. Int J Epidemiol 34(4):888–95. 

2005.

14. Mathews TJ, MacDorman MF, Thoma ME. Infant mortality statistics 

from the 2013 period linked birth/infant death data set. National Vital 

Statistics Reports; vol 64 no 9. Hyattsville, MD: National Center for Health 

Statistics. 2015.

15. Martin JA, Hamilton BE, Osterman MJK, Driscoll AK, Mathews TJ. 

Births: Final data for 2015. National Vital Statistics Reports; vol 66 no 1. 

Hyattsville, MD: National Center for Health Statistics. 2017.

Suggested citation

Ely DM, Hoyert DL. Differences between 

rural and urban areas in mortality rates for 

the leading causes of infant death: 

United States, 2013–2015. NCHS Data 

Brief, no 300. Hyattsville, MD: National 

Center for Health Statistics. 2018.

Copyright information

All material appearing in this report is in 

the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated.

National Center for Health 

Statistics 

Charles J. Rothwell, M.S., M.B.A., Director

Jennifer H. Madans, Ph.D., Associate 

Director for Science

Division of Vital Statistics

Delton Atkinson, M.P.H., M.P.H., P.M.P., 

Director

Hanyu Ni, Ph.D., M.P.H., Associate Director 

for Science

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