Research article
Rural–Urban Differences in Injury Hospitalizations in the U.S., 2004

https://doi.org/10.1016/j.amepre.2008.10.001Get rights and content

Background

Despite prior research demonstrating higher injury-mortality rates among rural populations, few studies have examined the differences in nonfatal injury risk between rural and urban populations. The objective of this study was to compare injury-hospitalization rates between rural and urban populations using population-based national estimates derived from patient-encounter data.

Methods

A cross-sectional analysis of the 2004 Nationwide Inpatient Sample was conducted in 2007. Rural–urban classifications were determined based on residence. SUDAAN software and U.S. Census population estimates were used to calculate nationally representative injury-hospitalization rates. Injury rates between rural and urban categories were compared with rate ratios and 95% CIs.

Results

An estimated 1.9 million (95% CI=1,800,250–1,997,801) injury-related hospitalizations were identified. Overall, injury-hospitalization rates generally increased with increasing rurality; rates were 27% higher in large rural counties (95% CI=10%, 44%) and 35% higher in small rural counties (95% CI=16%, 55%). While hospitalization rates for assaults were highest in large urban counties, the rates for unintentional injuries from motor vehicle traffic, falls, and poisonings were higher in rural populations. Rates for self-inflicted injuries from poisonings, cuttings, and firearms were higher in rural counties. The total estimated hospital charges for injuries were more than $50 billion. On a per-capita basis, hospital charges were highest for rural populations.

Conclusions

These findings highlight the substantial burden imposed by injury on the U.S. population and the significantly increased risk for those residing in rural locations. Prevention and intervention efforts in rural areas should be expanded and should focus on risk factors unique to these populations.

Introduction

Unintentional injuries are the leading cause of death in the U.S. among individuals aged 1–53 years and the fifth leading cause of death overall.1 Additionally, suicide and homicide rank as the second and third leading causes of death, respectively, among individuals aged 1–40 years.1 Prior research has demonstrated important differences in injury mortality between rural and urban populations. In general, rural populations have disproportionately high injury-mortality rates, and decreasing population density is the strongest predictor of county-specific trauma death rates in the U.S.2, 3, 4 Although homicide rates are higher among urban populations, the rates of suicide and unintentional injury are higher among rural populations, resulting in an overall higher injury-mortality rate among rural residents.2

Few studies have explored nonfatal injuries among rural populations. Published reports have generally been limited to individual states, specific mechanisms of injury, or both. Prior research, using survey methods, has examined the epidemiology of unintentional adult injury in a single rural county within Iowa5 and the prevalence and characteristics of nonfatal injury in urban and rural counties in Colorado.6 Results from Colorado suggested no significant difference between rural and urban areas. A second study7 of Colorado, also using survey methods, reported conflicting results, with the AOR for injury being 1.3 (95% CI=1.01, 1.68) for rural compared to urban residents. A third study8 from Colorado, focusing on traumatic brain injury (TBI) and using combined mortality and hospital-discharge data, found more significant rural–urban differences, with reported average annual age-adjusted rates of TBI of 97.8 per 100,000 population for the most-urban group to 172.1 per 100,000 population for residents of remote rural counties.

Emerging research has begun to provide some national estimates of injury morbidity among rural populations. Using 8 years of National Health Interview Survey (NHIS) data to examine nonfatal injury among children and youth, Danseco and colleagues9 reported a higher incidence and cost per injured child among those living in nonmetropolitan areas. This analysis, however, was limited to individuals aged ≤21 years. The analyses were also constrained by the lack of cause-of-injury coding within the NHIS, preventing an examination of differing injury mechanisms. Other investigators, using a redesigned NHIS, have recently reported findings of injury rates 26% higher in rural counties than in large urban counties in those aged ≥18 years.10

These valuable new findings have begun to shed some light on the substantial morbidity associated with nonfatal injuries and the disparate risk among rural populations. They are, however, based on survey methods, and they include data on all medically attended injuries leading to contact with a healthcare professional, either in person for treatment or by telephone for advice.10, 11 Because survey data are limited by potential self-report bias,12, 13 nonresponse error,14 and reliance on subject recall,15 a recent study16 concluded that surveys do not necessarily provide a method for ascertaining the burden of injuries that is as accurate or efficient as hospital-based encounter data. Additionally, hospital-discharge data add another dimension to the understanding of the total injury burden by identifying the most serious nonfatal injuries.17

This study utilized the largest sample of hospitalization data in the U.S. to derive population-based national estimates of injury-hospitalization rates, comparing the causes, characteristics, and costs of injuries between rural and urban populations. It was hypothesized that rural populations would demonstrate an overall increased risk of injury hospitalization and that the mechanisms of injury would vary, based on geographic residence.

Section snippets

Data Source

Data were obtained from the Nationwide Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project (HCUP) maintained by the Agency for Healthcare Research and Quality. HCUP data are derived from hospital-discharge summaries and abstracts, which are created by hospitals primarily for billing and payment purposes. Details of the HCUP process and methods have been previously described.18, 19

The NIS is a stratified probability sample of hospitals included in the HCUP and is designed to

Results

In 2004, there were an estimated 1.9 million (95% CI=1,800,250–1,997,801) injury-related hospitalizations in the U.S. Injury hospitalizations were equally distributed according to gender (Table 1). Approximately 51% of all patients hospitalized for injuries resided in large urban counties, whereas those residing in small urban, large rural, and small rural counties accounted for 28%, 12%, and 9% of cases, respectively (Table 1).

Nationwide in 2004, the estimated injury-hospitalization rate was

Discussion

The current findings confirm that those in rural counties experience a significantly increased risk for serious injury compared to those in large urban counties. Because these analyses are derived from hospital-discharge data, they represent injury cases serious enough to warrant hospitalization and, therefore, likely to incur substantial morbidity, lost productivity, or both. Residents of small rural counties had an injury-hospitalization rate that was 35% higher than the rate for those

References (34)

  • B. Gabella et al.

    Urban and rural traumatic brain injuries in Colorado

    Ann Epidemiol

    (1997)
  • T. Johnson et al.

    Modeling sources of self-report bias in a survey of drug use epidemiology

    Ann Epidemiol

    (2005)
  • J.H. Coben et al.

    Hospitalization for firearm-related injuries in the U.S., 1997

    Am J Prev Med

    (2003)
  • Web-based injury statistics query and reporting system (WISQARS)

    (2008)
  • C. Peek-Asa et al.

    Acute traumatic injuries in rural populations

    Am J Public Health

    (2004)
  • M.S. Eberhardt et al.

    Urban and rural health chartbook: health, U.S, 2001

    (2001)
  • R. Rutledge et al.

    A population-based study of the association of medical manpower with county trauma death rates in the U.S

    Ann Surg

    (1994)
  • D.L. Nordstrom et al.

    Epidemiology of unintentional adult injury in a rural population

    J Trauma

    (2001)
  • Prevalence and characteristics of injury in urban and rural Colorado, 1999 and 2000

    (2001)
  • M. Leff et al.

    Comparison of urban and rural non-fatal injury; the results of a statewide survey

    Inj Prev

    (2003)
  • E.R. Danseco et al.

    Incidence and costs of 1987–1994 childhood injuries: demographic breakdowns

    Pediatrics

    (2000)
  • H. Tiesman et al.

    Non-fatal injuries among urban and rural residents: the national health interview survey, 1997–2001

    Inj Prev

    (2007)
  • M. Warner et al.

    Injury and poisoning episodes and conditions: national health interview survey, 1997

    Vital Health Stat

    (2000)
  • J. Chung et al.

    Exploring social desirability bias

    J Bus Ethics

    (2003)
  • D.A. Dillman et al.

    The web questionnaire challenge to survey methodologists

  • A. Koch et al.

    The Greenland research database: a population-based research resource

    Int J Circumpolar Health

    (2003)
  • E. Petridou et al.

    Estimating the population burden of injuries: a comparison of household survey and emergency department surveillance

    Epidemiology

    (2004)
  • Cited by (0)

    View full text