This study determined the total occurrence of injuries in the general population of Korea and the incidence of occupationally related injury using answers related to injury from the KNHANES questionnaire and analyzed its association with socioeconomic factors. The proportion of subjects who sustained at least 1 injury in the 1-year period previous to the survey was 6.7%, and among the injured subjects, 2.4% were work-related injuries. Occupational injury accounted for 36.4% of all the reported injuries. In the Korean Working Conditions Survey sponsored by the Korean Department of Labor in 2006, 2010, and 2011, the average injury rate was 2.4%. The rate of occupational injury was 2%, and workplace injuries accounted for 84% of all the injuries received. A similar survey of 27 EU nations in 2005 revealed a mean injury rate of 9.1% (3.7%-21.5%)
. In the present study, the occupational injury rate was 2.4%, which was similar to the findings of the Korean Working Conditions Survey, but lower than the European average.
In previous studies, it was found that each increased level of socioeconomic status shows a better health status than the level below it in a dose–response relationship
, and this socioeconomic gradient is evident in both fatal
[23–34] and non-fatal injuries
[26, 28, 35–40]. We found the same in our study. As the levels of income and education increased, the injury incidence was reduced. The group with an annual income of more than 50 million won had an odds ratio of 0.54 (95% C.I.: 0.34-0.86) relative to the group with an income of less than 5 million won, and the group with a home valued at more than 500 million won had an odds ratio of 0.65 (95% C.I.: 0.43-0.96) compared to the group with a home valued at less than 50 million won. People with an elementary school education or below had an odds ratio of 1.89 (95% C.I.: 1.44-2.48) relative to those with a university or higher education. The injury rates that required a visit to an outpatient clinic and emergency room (Table
5) and that needed hospital admission were also higher in vulnerable socioeconomic groups who earned low income, had less education, owned a less expensive home, and worked in elementary labor. The results of our study were in accord with 2 previous studies.
The type of occupation and job status can also be factored in to consider the socioeconomic status
. The ‘craft, equipment, machine operating, and assembling worker’ group had the highest injury incidence of 10.6% among all of the occupational groups. ‘Skilled agricultural, forestry, and fishery worker’ (7.7%), ‘elementary worker’ (7.5%), ‘service and sales worker’ (6.1%), ‘clerk’ (6.7%), and ‘managerial and professional worker’ (6.0%) groups followed in that order, revealing concurrence with previous study results showing that manual labor has a higher risk of injury
[24, 26, 31, 36]. The unemployed had a significantly lower injury incidence than those with jobs, and their rate of seeking medical attention from an outpatient clinic or emergency room was also lower than those of the other groups. In addition, the unemployed group reported lower odds of injury than the other groups, and the group showed a particularly significant reduction in the odds of injury compared to ‘skilled agricultural, forestry, and fishery worker’, ‘craft, equipment, machine operating, and assembling worker’, and ‘elementary worker’ groups. This information contradicts previous studies reporting slightly but not significantly higher injury odds of 1.03 in the jobless than in those who were employed
. Our finding provides evidence that having a job may elevate injury risk. Our study also noted the smallest total number of injuries (5.7%) and injury risk in all subjects in the unemployed group, but the hospital admission rate, which reflects the severity of injury, was 2.3%, which was higher than the rate found in the white-collar worker group. This is in accord with a previous study that found the risk of mortality for jobless people was 2.26 times higher than that of other groups
. The reason for the higher risk can be explained by reports that noted a relationship with higher incidences of violent crime
 and suicide
Socioeconomic status is known to affect injury risk through a complex process. The causes of injuries originating from socioeconomic discrimination are psychosocial factors such as stress from poverty and intentional self-inflicted injury due to the stress from inequality as a result, raising the quality of material factors such as providing a livable income and adequate housing is effective in lowering the injury risk
. Lower socioeconomic status may result from poor housing and transportation, higher crime rates, and underemployment
[26, 41–43]. In addition to physical factors, there are occupation-related factors that also affect injury incidence
. Socioeconomic factors are also influenced by a geographical factor that has been interpreted as the degree of accessibility to various appropriate public services such as secure public safety measures, safe road, and recreational area. Also, a prosperous town has low crime rate. It has been suggested that the low crime rate is due to limiting strangers from accessing the town and encouraging good behavior among members of the community, and these positive activities have some protective value in preventing injury
. Those with a low socioeconomic level are likely to neglect the fact that injury is preventable, and this inattention may function as a factor that leads to the potential for injury
. A parent’s socioeconomic status is also an important factor in injury risk for children. Although the effect varies by the age and sex of a child, a parent’s efforts in providing their children with appropriate education, housing, and injury preventative measures are presently considered imperative for reducing injury risk
There present some limitations for this study. This study’s variables are obtained from a questionnaire and interview, and it is possible that the study is biased with recall bias from subjects. During the survey, surveyors tried to visit each subjects to obtain data directly. Data was not available from those who were admitted to a hospital or had deceased, and data from these subjects may be left out for interpretation. However, possibility of selection bias that may underestimates injury incidence is low, because fourth KNHANES was carried out as an individualized interview to each subject without knowing subjects’ trauma histories. Future studies further need more in-depth interviews and objective reviews on data to improve the analysis, and it is also considered that supplementing questions related injury, training surveyors, standardization of indicators, and checking reliability and validity of indicators are necessary to refine the outcomes in future studies. In this study, only a person’s income was taken in for socioeconomic evaluation, but the future studies need to consider obtaining more information on a person’s asset including car and financial asset for multidimensional interpretation. Lastly, there present a limitation to examine causal relationship between socioeconomic state and injury in this study, because it was a cross-section study. In order to investigate the causal relationship, a prospective cohort study is required.