Injury epidemiology of workers by age, sex and industrial classification using the medical claim data of National Health Insurance in South Korea, 2012-2015: a population-based retrospective study

Abstract

Objectives: This study aimed to evaluate the risk of inpatient hospitalisation for all-cause injuries, according to age, sex and industrial classification (IC) in South Korea.

Design: A population-based retrospective study.

Setting and participants: Data from the National Health Insurance Database on medical claims for the entire population of South Korean workers aged 25-59 years from January 2012 to December 2015 were retrieved. We observed 30 900 712 person-years (63.1%) in male workers and 18 105 272 person-years (36.9%) in female workers.

Main outcome measures: The inpatient hospitalisation for all-cause injury was defined as admission for which the principal diagnosis included S00-T98 in the Korean version of International Classification of Diseases-10 codes.

Results: Of 788 575 hospitalisations for all-cause injuries from 2012 to 2015, there were 565 107 cases in male workers (1 828.8 per 100 000 person-years) and 223 468 cases in female workers (1 234.3 per 100 000 person-years). The top five ICs with hospitalisation rate ratios (HRR) for all-cause injuries in both sexes compared with the financial intermediation IC included agriculture, hunting and forestry (HRR (95% CI); male: 2.09 (1.98 to 2.20); female: 1.53 (1.40 to 1.67)); mining and quarrying (male: 2.05 (1.92 to 2.19); female: 1.54 (1.27 to 1.87)) and fishing (male: 1.68 (1.57 to 1.80); female: 1.71 (1.51 to 1.93)). A U-shaped relationship occurred between age and risk for injuries in males; however, only a linear relationship was shown in females, regardless of IC.

Conclusions: The risk of injures varied by IC. The workers in agriculture, hunting, forestry, mining, quarrying and fishing were more vulnerable to injuries. The risk for injuries were higher among men and the age effect on this risk differed by sex. Thus, policy makers need to consider specific measures for prevention of injuries according to age, sex and IC.

Keywords: industrial classification; injury; medical claim data; occupational injury.

Figure 1

The crude, standardised rate per 100 000 person-years (PYs) and 95% CI of inpatient hospitalisation for all-cause injuries according to the industrial classification for workers aged 25–59 years in South Korea, 2012–2015. The standardised rate of hospitalisation for injury, poisoning and certain other consequences of external causes (S00–T98) was referenced for the population of insured employees reported by the National Health Insurance in 2015 (25–29 years of age, 1 732 065; 30–34 years of age, 2 151 548; 35–39 years of age, 2 119 908; 40–44 years of age, 2 222 646; 45–49 years of age, 2 115 189; 50–54 years of age, 1 801 657 and 55–59 years of age, 1 401 291). The industrial classification titles in the grey box of the figure are not the full names of the level 1 International Standard Industrial Classification of All Economic Activities (full names are shown in the online supplementary table 1-1).

Figure 2

The adjusted hospitalisation rate ratios (HRR), 95% CI of hospitalisation for all-cause injuries and trends for workers aged 25–59 years in South Korea, 2012–2015. The age and year adjusted HRR for each stratum was compared with those of the employees aged 25–29 years, by sex, respectively. The dark grey line indicates the smooth non-parametric curve using a loess smoother (the loess span 1.00) and the grey shadow indicates the 95% CI of smooth curve.

Figure 3

The year-adjusted and age-adjusted hospitalisation rate ratio (HRR) and 95% CI of hospitalisations for all-cause injuries according to industrial classification, 2012–2015. The age-adjusted and year-adjusted HRR for each stratum was compared with that of the employees aged 25–29 years insured in the financial intermediation, by sex, respectively; The industrial classification titles in the grey box of figure are not the full names of the level 1 International Standard Industrial Classification of All Economic Activities (the full names are shown in online supplementary table 1-1).