Main results of the Korea National Hospital Discharge In-depth Injury Survey, 2004-2016

Article information

Epidemiol Health. 2020;42.e2020044
Publication date (electronic) : 2020 June 20
doi : https://doi.org/10.4178/epih.e2020044
1Division of Chronic Disease Control, Korea Centers for Disease Control and Prevention, Cheongju, Korea
2Occupational Health Research Department, Korea Occupational Safety and Health Agency, Ulsan, Korea
3Public Health and Medical Service Office, Chungnam National University Hospital, Daejeon, Korea
Correspondence: Youngtaek Kim Public Health and Medical Service Office, Chungnam National University Hospital, 282 Munhwa-ro, Jung-gu, Daejeon 35015, Korea E-mail: ruyoung01@cnuh.co.kr
Received 2020 February 10; Accepted 2020 June 20.

Abstract

OBJECTIVES

The purpose of this study was to estimate the incidence of injuries and to identify their causes by classifying injuries according to various categories including age, sex, mechanism of injury, body parts injured, and place of injury.

METHODS

This study used data from the Korea National Hospital Discharge In-depth Injury Survey (KNHDIS) from 2004 to 2016. The KNHDIS is conducted annually by the Korea Centers for Disease Control and Prevention, and its survey population includes all hospitalized patients discharged from medical institutions that have 100 or more beds, such as hospitals, general hospitals, and secondary community health centers. The number of injured cases is weighted and estimated using the mid-year estimated population of each year.

RESULTS

The injury discharge rate steadily increased since 2004 (1,505 per 100,000 population in 2004, 2,007 per 100,000 population in 2016) and most injuries were unintentional (annual average of 94.7%). On average, during the 13-year study period, the injury rate for males was 1.5 times as high as for females. The 2 main causes of injury were consistently traffic accidents and falls. Notably, the rate of injuries resulting from falls rose by 1.7-fold from 463 to 792 per 100,000 people, and exceeded the rate of traffic accidents in 2016.

CONCLUSIONS

The incidence of injuries steadily increased after the survey was first conducted, whereas mortality resulting from injuries mostly remained unchanged. This suggests that effective strategies and interventions should be reinforced to reduce unintentional injuries.

INTRODUCTION

An injury is defined as intentional or unintentional physical and/or psychological damage resulting from an external cause, including conditions such as trauma and poisoning [1]. The World Health Organization classifies injuries as a non-communicable disease (a category that also includes chronic diseases) because injuries follow a chronic course until a previously normal status is restored and often result in residual psychological or biological sequelae. Injuries occur in various circumstances such as violence in schools, industrial disasters, road accidents, agricultural accidents, and accidents at festivals. Injuries are handled by diverse social safety sectors depending on where they occur and whether they are intentional; therefore, there is a need to unify dispersed data to obtain a holistic overview of the epidemiology of injuries.

Korea is ranked as one of the top countries with regard to mortality resulting from injuries [2]. The situations regarding traffic accidents involving children and mortality from industrial accidents were similar to each other, and even though Korea’s safetyrelated indices greatly improved after it joined the Organization for Economic Cooperation and Development (OECD), it still failed to reach OECD standards [3,4].

An analysis of injury-related disease codes in 2016 revealed that the direct health expenditures on injuries covered by national health insurance amounted to 4.0 trillion Korean won (KRW; 2.2 trillion KRW on admissions, 1.8 trillion KRW on outpatients) which accounted for 10% of all medical costs. This reflected a 3-fold increase in injury-related health expenditures since 2004, when expenditures on injuries totaled 1.4 trillion KRW (0.7 trillion KRW on admissions, 0.7 trillion KRW on outpatients) [5].

The social cost due to road accidents, one of the major causes of unintentional injuries, was 26.6 trillion KRW (1.9% of gross domestic product [GDP]) in 2014 [6]. This was a 9.5% increase from the 24.0 trillion KRW spent in 2013 and approximately triple the 9.7 trillion KRW (1.1% of GDP) spent in 2006 [7,8]. The loss of working days due to industrial disasters in 2016 was 47,040, and the estimated economic losses amounted to 21.4 trillion KRW. This was a 4.9% increase from the estimated economic loss of 20.4 trillion KRW in 2015 and double the estimated economic loss of 10.1 trillion KRW in 2002 [9]. It has been estimated that for every 600 near-miss cases of injury, there are 30 cases of property damage, 10 mild injuries, and 1 major injury (the 1-10-30-600 accident ratio) [10,11]. This suggests that the total costs of injuries would be much greater if unidentified injuries were included.

The Korea Centers for Disease Control and Prevention developed the Korea National Hospital Discharge In-depth Injury Survey (KNHDIS), a national representative survey of injury-related discharges from general hospitals in 2005 to understand the scale of injuries, to identify risk factors, and to provide data supporting prevention policies and intervention strategies. On the basis of this nationally representative injury survey, the total number of injuries severe enough to require admission can be estimated. We investigated trends from 2004 to 2016 and reported updated national injury incidence estimates in Korea since 2004.

MATERIALS AND METHODS

The KNHIDS, which has been conducted since 2004, collects data on approximately 9% of discharged cases from medical institutions with 100 or more beds, including hospitals, general hospitals, and secondary community health centers. Hospitals with a single specialty, long-term care hospitals, geriatric hospitals, military hospitals, and rehabilitation hospitals were excluded even if they had 100 or more beds. The KNHDIS applied stratified 2-stage cluster sampling, with individual hospitals as the primary sampling unit and discharged patients in a sampled hospital as the secondary sampling unit. The hospitals were sampled based on clusters of hospitals stratified by geographic location and number of beds. The hospitals were divided into 4 categories according to the number of beds (100-299, 300-499, 500-999, and over 1,000 beds). Data were collected on patients’ age, sex, residence zip code, type of insurance, diagnostic code based on the International Classification of Diseases 10th revision, hospital admission date and discharge date, and injury-related codes such as the mechanism and place of injury occurrence based on the International Classification of External Causes of Injuries version 1.2.

The KNHDIS data captured multiple admissions with no distinction between initial admissions and readmissions. Approximately 230,000 hospitalizations, including multiple admissions, were reviewed every year, from which 30,000 injury cases were identified and examined. The survey was a complex sample survey, and appropriate weights were applied for the estimation. The number of injured cases was estimated using the mid-year estimated population of each year. Linear variance estimation was carried out using the Taylor series, with the SURVEYMEANS procedure provided by SAS version 9.4 (SAS Institute Inc., Cary, NC, USA) [12].

Ethics statements

The study was exempt from institutional review board approval as the KNHIDS was conducted a part of national injury surveillance system and all analyses in this study were used public-open data.

RESULTS

In 2016, 170 sample hospitals were selected out of 561 hospitals, and the estimated total number of discharged injury cases was 1,170,713. This corresponded to 16.5% of the total of discharges for all causes. The injury discharge rate (per 100,000 population) for males was 1.5 times as high as for females during the surveyed period (1.4 to 1.6). Furthermore, the injury discharge rate showed a linear increase, from 1,505 per 100,000 population in 2004 to 2,007 per 100,000 population in 2016.

The injury discharge rate increased with age, and this trend was stable over time. However, the difference in the discharge rate between children aged under 12 years old and people aged over 65 years old in each year widened, from 3.7-fold in 2004 (897 vs. 3,360 per 100,000 population) to 6.5-fold in 2016 (750 vs. 4,887 per 100,000 population). In 2016, patients aged 0-12 displayed the lowest rate (750 per 100,000 population), while the age group of 65 years old and over had a 6.5 times higher value of 4,887. Most injuries were unintentional (93.1% in 2004, 96.4% in 2016) over this period. The traffic accident rate peaked at 772 people per 100,000 people in 2010, and the discharge rate for injuries caused by traffic accidents reached 669 people per 100,000 in 2016, similar to the rate in 2004. The major causes of unintentional injuries were falls (39.4%), traffic accidents (33.4%), and struck by/against injuries (9.7%) in 2016, whereas the major causes in 2004 were traffic accidents (44.5%), falls (30.6%), and struck by/against injuries (6.8%). Furthermore, the discharge rate due to assault decreased by 54.8% from 73 per 100,000 population in 2004 to 40 per 100,000 population in 2016, while that of self-harm injuries remained mostly unchanged (38 per 100,000 people in 2004, 34 per 100,000 people in 2016) (Table 1).

Estimated injury discharge rates, 2004-2016

In the 0-12 age group, the number of injury discharges decreased by 59.3% from 67,800 in 2004 to 40,234 in 2016 due to a significant decline of traffic accidents (8,642 in 2016, 26,705 in 2004), which resulted in a sharp drop in roadway injuries.

The number of injuries in the adolescent age group (13-18 years old) and young adults/middle-aged group (19-64 years old) increased by 1.4-fold and 1.2-fold from 2004 to 2016, respectively.

In the elderly group (aged 65 and over), the number of discharged injury cases was 298,208 in 2016, a 1.9-fold increase from 2004. The 2 main causes of injuries were falls (52.4% in 2004, 57.5% in 2016) and traffic accidents (26.7% in 2004, 21.0% in 2016) over this period, although the most dramatic increase was found for struck by/against injuries, the rate of which was 3 times higher in 2016 than in 2004.

Injuries from fractures declined in children (under 12 years old), but rose in older age groups; in particular, in the elderly group (aged 65 and over) the number of injuries from fractures increased by more than 3 times, from 68,370 to 182,455 (Table 2).

Characteristics of injuries by age group

DISCUSSION

Injuries are the leading cause of death in young people aged 10-30 years old, and play a major role in causing premature death at all ages [13]. To establish sustainable development and to reach the standards of developed countries, the rising trend of the incidence of injuries needs to be reversed through safety promotion initiatives. The total incidence of injuries steadily increased since 2004 in this study. Despite the increased incidence of injuries over the last 10 years, the mortality rate due to injuries has remained stable. This suggests that preventative measures against injuries have not been as effective as measures that address their aftermath. A marked increase in injuries in the elderly has resulted in growing medical costs for chronic diseases, with negative impacts on quality of life; as such, injuries in the elderly have the potential to become a huge obstacle to health promotion in Korean society, which is now in an advanced-age era. On the one hand, there have been improvements in survival and functional recovery after serious injuries due to advances in the treatment of emergencies and in the medical system. On the other hand, close attention needs to be paid in order to reduce the incidence of injuries by reinforcing preventative activities that target what happens before accidents and to yield a synergistic effect with health policies aimed at dealing with what happens subsequent to accidents. Furthermore, according to recent study, regional variations need to be prioritized with individual variations such as age and sex [14].

There are several limitations to this study. First, the KNHDIS captured injuries in patients admitted to hospitals with over 100 beds because the KNHIDS was designed to assess trends at the national level, and detailed information on injuries that were recorded as unknown was not identified. As community and individual risk factors were found to influence the risk of hospitalization for unintentional injuries [14], the surveillance system will be considered as a way to collect data at the community level and on geographical characteristics for developing intervention strategies and implementing prevention programs. Although this was a comparative study over time, we utilized the crude rates in the published statistics of the KNHIDS; thus, future research should use age-adjusted data. Despite these limitations, this survey data allowed us to estimate the number of injury cases on the national scale according to injury mechanism, so the present findings have value for utilization in policy-making to prevent injuries. Further comparative research is needed to identify relevant risk factors to reduce unintentional injuries, drawing upon linkage with various sources of health data such as the Korea National Health and Nutrition Examination Survey.

Notes

The authors have no conflicts of interest to declare for this study.

FUNDING

None.

AUTHOR CONTRIBUTIONS

Conceptualization: YK. Data curation: SOH, BK. Formal analysis: YK, BK. Funding acquisition: None. Methodology: YK, YK. Project administration: YK, SOH, YKL. Visualization: YK, JJ, YKL. Writing-original draft: YK, JJ, OH, BK. Writing-review & editing: YK, YKL.

Acknowledgements

This article is based on a previous article entitled “Epidemiological characteristics of patients admitted for injured inpatients in Korea, 2015” published in “Public Health Weekly Report, 2018; Vol.11, No.11”, which is the newsletter of the Korea Centers for Disease Control and Prevention. However, according to subparagraph 306 of the rules and regulations of the publication, its contents can be reused in other publications without copyright issues. Moreover, data from 2016 were used in this article, whereas data from 2015 were used in the previous article, further negating the issue of duplicate submission.

References

1. World Health Organization. Manifesto for Safe Communities: safety - a universal concern and responsibility for all [cited 2020 May 9]. Available from: https://www.iadt-dentaltrauma.org/Manifesto%20for%20safe%20communities.pdf.
2. Organization for Economic Cooperation and Development. Health status: causes of mortality [cited 2020 May 9]. Available from: https://stats.oecd.org/index.aspx?queryid=30115.
3. International Labour Organization. Fatal occupational injuries per 100,000 workers by sex and migrant status-annual [cited 2020 Jul 13]. Available from: https://www.ilo.org/shinyapps/bulkexplorer38/?lang= en&segment= indicator&id=INJ_FATL_SEX_MIG_RT_A.
4. International Transport Forum. Road safety annual report 2018 [cited 2020 Jul 13]. Available from: https://www.itf-oecd.org/sites/default/files/docs/irtad-road-safety-annual-report-2018_0.pdf.
5. Health Insurance Review & Assessment Service. 2016 National health insurance statistical yearbook. 2017. [cited 2020 Jul 14]. Available from: https://www.hira.or.kr/bbsDummy.do?pgmid=HIRAA020045010000&brdScnBltNo=4&brdBltNo=2293&pageIndex=4 (Korean).
6. Park K, Han M, Lee U, Jang S, Yu G, Kim Y, et al. Estimation and evaluation of road traffic accident cost Wonju: Road Traffic Authority; 2015. p. 85. (Korean).
7. Chang T, Kim T, Lee U, Jang S, Jo H, Yu G, et al. Estimation and evaluation of road traffic accident cost Seoul: Road Traffic Authority; 2014. p. 85. (Korean).
8. Jang Y, Park H, Jo H, Lee U, Yu C, Hwang J, et al. Estimation and evaluation of road traffic accident cost Seoul: Road Traffic Authority; 2007. p. 63. (Korean).
9. Ministry of Employment and Labor. 2015 Industrial disaster occurrence current status and analysis Sejong: Ministry of Employment and Labor; 2016. p. 9. (Korean).
10. Lee J, Kim Y, Jeong G, Park H, Kim J, Eun S, et al. Accident statistics database establishment and analysis and research of current status. [cited 2019 Jan 24]. Available from: www.snu-dhpm.ac.kr/pds/files/안전사고통계DB%20최종보고서(공단).pdf (Korean).
11. Frank E, Bird FE, George L, Germain GL. Practical loss control leadership Loganville: Det Norske Veritas; 1996. p. 21.
12. Lee KO. A study on sampling design and weighting for Korea hospital discharge survey Seoul: Korea Centers for Diseases Control and Prevention; 2007. p. 29–56. (Korean).
13. Kim J, Kim RH. 2017 Causes of mortality Daejeon: Statistics Korea; 2018. p. 9. (Korean).
14. Park HS. Investigation of injury-related risk factors affecting Injury hospitalization using multiyear data from the Korea national hospital discharge injury surveillance Cheongju: Korea Centers for Diseases Control and Prevention; 2017. p. 79–255. 79-114, 255. (Korean).

Article information Continued

Table 1.

Estimated injury discharge rates, 2004-2016

Characteristics 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Total (n) 1,773 1,871 1,939 1,956 2,010 2,061 2,241 2,199 2,312 2,301 2,313 2,356 2,285
Sex
 Male 2,182 2,269 2,379 2,368 2,390 2,452 2,638 2,571 2,694 2,639 2,620 2,644 2,512
 Female 1,359 1,470 1,495 1,541 1,628 1,667 1,843 1,825 1,929 1,962 2,006 2,068 2,056
Age (yr)
 0-12 897 875 818 825 880 832 858 856 882 867 889 822 750
 13-18 961 1,098 1,190 1,257 1,356 1,382 1,463 1,582 1,592 1,490 1,533 1,635 1,471
 19-64 1,886 1,986 2,033 2,061 2,052 2,122 2,252 2,193 2,262 2,244 2,197 2,229 2,120
 ≥65 3,360 3,508 3,776 3,550 3,856 3,820 4,446 4,216 4,615 4,564 4,735 4,784 4,887
Intent
 Unintentional 1,505 1,590 1,622 1,669 1,721 1,762 1,947 1,913 2,021 2,006 2,015 2,070 2,007
 Intentional 111 113 114 106 112 106 105 101 92 92 90 82 74
  Self-harm 38 39 43 33 40 39 40 39 37 40 37 37 34
  Assault 73 74 72 72 71 67 65 62 54 52 53 45 40
  Unknown 10 10 15 12 4 4 5 -1 6 19 16 17 6
Mechanism
 Traffic accident 669 690 714 746 743 745 772 733 771 729 731 738 670
 Falls 463 491 518 504 532 558 654 668 703 748 736 783 792
 Struck by/against 164 173 246 243 242 239 238 263 274 248 251 252 231
 Poisoning 47 47 61 52 55 58 58 55 57 57 59 53 50
 Stabbing 86 141 87 72 77 68 74 67 69 75 62 68 77
 Unknown 262 292 189 219 250 257 290 286 301 309 320 319 331

Values are presented as number per 100,000 population.

1

Estimates with relative standard error of less than 5.

Table 2.

Characteristics of injuries by age group

Characteristics 0-12
13-18
19-64
≥65
2004 2016 2004 2016 2004 2016 2004 2016
Total 67,800 40,234 34,424 48,223 557,174 682,614 122,049 298,208
Intention
 Unintentional 67,072 39,934 30,613 44,737 509,023 652,438 116,313 291,179
 Self-harm 753 - 4133 711 15,125 12,489 2,882 4,146
 Assault 5783 2803 3,311 2,629 29,611 16,035 1,4473 1,559
 Unknown1 753 203 883 1463 3,414 1,652 1,408 1,324
Mechanism
 Traffic accident 26,705 8,642 12,194 15,770 250,025 256,178 32,567 62,663
 Fall 20,980 16,158 9,819 12,875 127,503 205,226 63,991 171,354
 Struck by/against 4,899 5,702 7,603 10,095 62,418 87,964 3,834 14,851
 Stabbing 3,209 1,372 2,514 1,789 34,270 32,109 1,505 4,315
 Fire/heat/flame 4,662 4,2693 - - - - - -
 Poisoning - - 1943 667 16,883 16,573 4,821 8,087
 Unknown1 7,345 4,091 2,101 7,027 66,075 84,564 15,331 36,938
Source of traffic accident
 Subtotal 26,705 8,642 12,194 15,770 250,025 256,178 32,566 62,663
 Pedestrian 14,245 3,797 2,415 2,530 31,841 30,631 8,582 16,099
 Bicycle 4,295 2,466 1,357 2,964 9,441 22,044 2,907 6,975
 Motorcycle - - 4,205 5,622 24,776 24,167 5,293 10,449
 Automobile 5,672 2,160 3,103 3,817 134,558 152,443 5,612 18,079
 Unknown1 2,493 2193 1,1143 8373 49,409 26,893 10,172 11,061
Place of injury
 Residence 16,905 8,885 3,337 2,814 58,273 65,448 34,717 78,504
 School 5,255 3,331 4,611 4,345 - - - -
 Field/stadium 3,840 2,329 3,410 6,172 15,798 20,060 - -
 Roadway 22,754 8,714 12,926 16,312 237,336 270,717 31,501 71,782
 Workplace - - - - 6,361 42,078 - -
 Farm - - - - - - 1,2553 10,245
 Lake·Steam·sea·outdoor - - - - - - - 5,816
 Unknown1 19,046 16,975 10,140 18,580 239,406 284,311 54,576 131,861
120,794 298,208
Nature of injury
 Fracture 25,166 19,843 15,221 19,379 167,256 235,910 68,370 182,455
 Dislocation2 2313 1903 3303 888 4,807 8,608 1,3713 1,947
 Sprain/strain2 3,290 2,197 3,756 10,974 127,891 178,330 8,892 23,992
 Internal organ 12,813 4,305 6,004 4,356 101,031 77,773 21,291 35,477
 Open wound 8,734 2,330 2,715 1,523 36,204 25,589 4,830 9,036
 Traumatic amputation 9373 1083 723 733 10,3553 4,656 1,1083 5343
 Vascular injury 153 1113 - 1403 2,336 2,472 1453 5273
 Contusion·superficial injury 4,638 3,177 2,138 3,738 32,447 42,885 5,796 17,277
 Crush injury 1,7553 463 2063 1033 10,388 1,962 6823 3753
 Burn 5,8723 4,6073 6133 8793 14,198 19,2293 2,106 6,423
 Nerve injury 1383 2593 4853 1543 2,957 2,992 1193 4053
 Poisoning 723 533 2273 668 19,033 15,414 6,749 7,870
 Others 4,201 2,494 3,466 5,205 36,620 66,016 4,255 11,728
 Unknown1 526 343 3383 1433 4,178 778 2183 1623

Values are presented as number of estimated cases.

1

Unknown includes unclassified cases.

2

Dislocations, sprains, and strains were collected without a detailed classification.

3

Estimates with relative standard error of 25% or greater.