Normal: BMI< = 23.9, overweight: 24 = = 27) was used to classify BMI. Overweight and obesity were classified together into a group in the analysis. The EPQ-REC original score was transformed into a T score according to Chinese norms, and then categorized into three groups (<43.3, 43.3?6.7 and >56.7). Job burnout total score was also categorized into three groups(<50, 50?75 and !75). The outcome variable considered in the model was categorized as a dichotomous variable (injury or no-injury). To access the relationships GW9662 web between various factors with injury, the crude odds ratios (OR) and their 95 confidence intervals (CI) were calculated with univariate logistic regression. The adjusted odds ratios (ORa) were then estimated using multivariable logistic regression with stepwise procedure. All these statistical analysis were conducted using SAS version 9.3 (SAS Institute, Inc., Cary, NC, USA), and a level of 0.05 was used to declare statistical significance.ResultsA total number of 3618 effective respondents were got from the 4319 participants who had been recruited (83.77 ). The mean age of coal miners was 41.5 years with standard deviation 8.65. The median time that passed between each participant’s last injury and their interview was 1.54 years. Table 1 shows that there were 137 reported accidents among the 3618 coal workers (3.79 ) who experienced at least one accident. The total number of injuries was 138: with one accident n = 136 (3.76 ); with two accidents n = 1 (0.03 ). Table 2 presents the distribution of injuries according to workplace, type of injury, localization of injury and severity of injury. For all injuries, underground represented about 79.71 , and above ground about 20.29 . Smashing injury was the most common pnas.1408988111 injury accounting for 53.63 , sprains and luxation 23.92 . The localization of injury happened mainly in limbs (57.25 ), followed by head and face (18.12 ) and trunk (17.39 ). The majority of injuries (60.87 ) were minor injury. Table 3 indicates that workplace dangerousness had significant differences in different age groups. Workers aged 55 or more tended to rate their workplace as never dangerous, more often than younger workers. Significant differences also existed between males and females.Table 1. Distribution of wcs.1183 the nonfatal occupational injures ( ). The number of injuries 0 1 2 Total doi:10.1371/journal.pone.0134367.t001 Frequencies (n) 3481 136 1 3618 Proportion ( ) 96.21 3.76 0.03 100.0 3.76 0.03 Prevalence ( )PLOS ONE | DOI:10.1371/journal.pone.0134367 July 31,5 /The Risk Factors of Nonfatal Occupational Injury in the Coal WorkersTable 2. Characteristic distribution of nonfatal occupational injuries. Variable Type of injury Characteristics smashing injury blast injury mechanical traffic injury falling injury sprains and luxation poisoning others Localization of injury head and face trunk limbs whole body others Severity of injury minor moderate serious doi:10.1371/journal.pone.0134367.t002 Table 3. The Aviptadil structure danger of the work environment in different groups. The danger of the work environment ( ) Never Age 25yr 25 35yr 35 45yr 45 55yr !55yr Gender male female doi:10.1371/journal.pone.0134367.t003 24.72 26.65 27.50 29.37 40.25 20.90 68.79 Seldom 19.10 15.53 17.58 17.78 20.34 17.58 16.03 Sometimes 26.97 24.70 25.09 25.70 20.76 27.98 8.97 Often 13.48 14.13 11.12 11.50 10.17 13.53 3.97 Usually 15.73 18.99 18.71 15.65 8.47 20.01 2.24 <0.001 0.008 P n 74 5 9 5 33 3 9 25 24 79 3 7 84 50 4.Normal: BMI< = 23.9, overweight: 24 = = 27) was used to classify BMI. Overweight and obesity were classified together into a group in the analysis. The EPQ-REC original score was transformed into a T score according to Chinese norms, and then categorized into three groups (<43.3, 43.3?6.7 and >56.7). Job burnout total score was also categorized into three groups(<50, 50?75 and !75). The outcome variable considered in the model was categorized as a dichotomous variable (injury or no-injury). To access the relationships between various factors with injury, the crude odds ratios (OR) and their 95 confidence intervals (CI) were calculated with univariate logistic regression. The adjusted odds ratios (ORa) were then estimated using multivariable logistic regression with stepwise procedure. All these statistical analysis were conducted using SAS version 9.3 (SAS Institute, Inc., Cary, NC, USA), and a level of 0.05 was used to declare statistical significance.ResultsA total number of 3618 effective respondents were got from the 4319 participants who had been recruited (83.77 ). The mean age of coal miners was 41.5 years with standard deviation 8.65. The median time that passed between each participant's last injury and their interview was 1.54 years. Table 1 shows that there were 137 reported accidents among the 3618 coal workers (3.79 ) who experienced at least one accident. The total number of injuries was 138: with one accident n = 136 (3.76 ); with two accidents n = 1 (0.03 ). Table 2 presents the distribution of injuries according to workplace, type of injury, localization of injury and severity of injury. For all injuries, underground represented about 79.71 , and above ground about 20.29 . Smashing injury was the most common pnas.1408988111 injury accounting for 53.63 , sprains and luxation 23.92 . The localization of injury happened mainly in limbs (57.25 ), followed by head and face (18.12 ) and trunk (17.39 ). The majority of injuries (60.87 ) were minor injury. Table 3 indicates that workplace dangerousness had significant differences in different age groups. Workers aged 55 or more tended to rate their workplace as never dangerous, more often than younger workers. Significant differences also existed between males and females.Table 1. Distribution of wcs.1183 the nonfatal occupational injures ( ). The number of injuries 0 1 2 Total doi:10.1371/journal.pone.0134367.t001 Frequencies (n) 3481 136 1 3618 Proportion ( ) 96.21 3.76 0.03 100.0 3.76 0.03 Prevalence ( )PLOS ONE | DOI:10.1371/journal.pone.0134367 July 31,5 /The Risk Factors of Nonfatal Occupational Injury in the Coal WorkersTable 2. Characteristic distribution of nonfatal occupational injuries. Variable Type of injury Characteristics smashing injury blast injury mechanical traffic injury falling injury sprains and luxation poisoning others Localization of injury head and face trunk limbs whole body others Severity of injury minor moderate serious doi:10.1371/journal.pone.0134367.t002 Table 3. The danger of the work environment in different groups. The danger of the work environment ( ) Never Age 25yr 25 35yr 35 45yr 45 55yr !55yr Gender male female doi:10.1371/journal.pone.0134367.t003 24.72 26.65 27.50 29.37 40.25 20.90 68.79 Seldom 19.10 15.53 17.58 17.78 20.34 17.58 16.03 Sometimes 26.97 24.70 25.09 25.70 20.76 27.98 8.97 Often 13.48 14.13 11.12 11.50 10.17 13.53 3.97 Usually 15.73 18.99 18.71 15.65 8.47 20.01 2.24 <0.001 0.008 P n 74 5 9 5 33 3 9 25 24 79 3 7 84 50 4.