Proportion ( ) 53.63 3.62 6.52 3.62 23.92 2.17 6.52 18.12 17.39 57.25 2.17 5.07 60.87 36.23 2.68.79 females rated their workplace as never dangerous, but for males the value was only 20.90 . Table 4 observes that 79.59 males performed physical labor, and females 45.68 . Current smoking and drinking status had significant differences between physical labor and mental labor groups.Table 4. Comparison of gender, smoking and drinking status between two journal.pone.0077579 groups. Work type Physical labor N ( ) Gender Smoking Drinking male female yes no yes no doi:10.1371/journal.pone.0134367.t004 2418(79.59) 266(45.86) 1686(81.73) 998(64.18) 1127(77.40) 1557(72.02) Mental labor N ( ) 620(20.41) 314(54.14) 377(18.27) 557(35.82) 329(22.60) 605(27.98) 0.003 <0.001 <0.001 PPLOS ONE | DOI:10.1371/journal.pone.0134367 July 31,6 /The Risk Factors of Nonfatal Occupational Injury in the Coal WorkersUnivariate analysisTo start with, all suggested factors were investigated as possible independent variables by fitting the univariate logistic regression model in which the dependent variable is dichotomous, notably presence or absence of an injury. The distribution of injury showed that among those workers who gave history of injuries, male represented about 97.08 (133), female 2.92 (4). The majority of the injured were between 25 to 45 years old (72.27 ). About 91.24 of the injured were married, and 64.23 completed junior college or senior high school. Table 5 shows that significant crude odds ratios (OR) were observed for all factors considered except for marital status, education, work duration, BMI, EPQ-RSC(P) scale and EPQ-RSC(L) scale. Male, age, heavy physical work, ML240 web underground front-line, length of shiftwork experience, monthly income (6,000?,000RMB), average or bad sleep, smoking, drinking, job burnout, job dissatisfaction, introversion and emotional instability had significant associations with a higher risk of occupational injury.Multivariable Procyanidin B1MedChemExpress Procyanidin B1 analysisBased on the results from the univariate logistic regression models, we perform a multivariable logistic regression analysis by using the stepwise method (criterion for entry = 0.05 and retention = 0.1) with all the variables that could be selected as suggested injury risk factors (univariate p< 0.05). Variance inflation factors (VIF) was used to detect collinearity with the SAS command PROC REG, and the result indicated that there was no evidence of multicollinearity as all VIF values were less than 10. As noted in Table 6, 1.07839E+15 significant adjusted odds ratios were found for gender (female vs male 0.275, 0.094?.800), age (!55 vs 25yr 0.169, 0.032?.900), work type (light physical labor vs heavy physical labor 0.504, 0.328?.774), workplace (underground auxiliary vs underground front-line 0.595, 0.385?.919), length of shiftwork experience (0 5yr vs no shift 2.075, 1.287?.344 and !15yr vs no shift 2.076, 1.230?.504). EPQ-RSC(E) score showed that introversion had a higher risk of injury than extraversion (extraversion vs introversion 0.538, 0.334?.867).DiscussionThis cross-sectional study demonstrates that male, heavy physical labor, underground frontline, length of shiftwork experience (0 5yr, !15yr) and introversion were associated with markedly higher risks of nonfatal occupational injury. Older workers were less likely to be injured rather than those under the age of 25. It should be noted that the median time that passed between each participant’s last injury and their interview was 1.54 years. Time interval is.Proportion ( ) 53.63 3.62 6.52 3.62 23.92 2.17 6.52 18.12 17.39 57.25 2.17 5.07 60.87 36.23 2.68.79 females rated their workplace as never dangerous, but for males the value was only 20.90 . Table 4 observes that 79.59 males performed physical labor, and females 45.68 . Current smoking and drinking status had significant differences between physical labor and mental labor groups.Table 4. Comparison of gender, smoking and drinking status between two journal.pone.0077579 groups. Work type Physical labor N ( ) Gender Smoking Drinking male female yes no yes no doi:10.1371/journal.pone.0134367.t004 2418(79.59) 266(45.86) 1686(81.73) 998(64.18) 1127(77.40) 1557(72.02) Mental labor N ( ) 620(20.41) 314(54.14) 377(18.27) 557(35.82) 329(22.60) 605(27.98) 0.003 <0.001 <0.001 PPLOS ONE | DOI:10.1371/journal.pone.0134367 July 31,6 /The Risk Factors of Nonfatal Occupational Injury in the Coal WorkersUnivariate analysisTo start with, all suggested factors were investigated as possible independent variables by fitting the univariate logistic regression model in which the dependent variable is dichotomous, notably presence or absence of an injury. The distribution of injury showed that among those workers who gave history of injuries, male represented about 97.08 (133), female 2.92 (4). The majority of the injured were between 25 to 45 years old (72.27 ). About 91.24 of the injured were married, and 64.23 completed junior college or senior high school. Table 5 shows that significant crude odds ratios (OR) were observed for all factors considered except for marital status, education, work duration, BMI, EPQ-RSC(P) scale and EPQ-RSC(L) scale. Male, age, heavy physical work, underground front-line, length of shiftwork experience, monthly income (6,000?,000RMB), average or bad sleep, smoking, drinking, job burnout, job dissatisfaction, introversion and emotional instability had significant associations with a higher risk of occupational injury.Multivariable analysisBased on the results from the univariate logistic regression models, we perform a multivariable logistic regression analysis by using the stepwise method (criterion for entry = 0.05 and retention = 0.1) with all the variables that could be selected as suggested injury risk factors (univariate p< 0.05). Variance inflation factors (VIF) was used to detect collinearity with the SAS command PROC REG, and the result indicated that there was no evidence of multicollinearity as all VIF values were less than 10. As noted in Table 6, 1.07839E+15 significant adjusted odds ratios were found for gender (female vs male 0.275, 0.094?.800), age (!55 vs 25yr 0.169, 0.032?.900), work type (light physical labor vs heavy physical labor 0.504, 0.328?.774), workplace (underground auxiliary vs underground front-line 0.595, 0.385?.919), length of shiftwork experience (0 5yr vs no shift 2.075, 1.287?.344 and !15yr vs no shift 2.076, 1.230?.504). EPQ-RSC(E) score showed that introversion had a higher risk of injury than extraversion (extraversion vs introversion 0.538, 0.334?.867).DiscussionThis cross-sectional study demonstrates that male, heavy physical labor, underground frontline, length of shiftwork experience (0 5yr, !15yr) and introversion were associated with markedly higher risks of nonfatal occupational injury. Older workers were less likely to be injured rather than those under the age of 25. It should be noted that the median time that passed between each participant’s last injury and their interview was 1.54 years. Time interval is.
