## 3 Results
### Distribution and Sick Leave Days of Elbow MSDs and Factors Associated with Elbow MSDs  
Table 5 shows the distributions of total MSDs and elbow MSDs and the mean and SD of sick leave days by workers' occupation, age, MSD type, work experience, and company size. According to occupations, there was a significant difference in frequency distributions between elbow MSDs and the other MSDs (\(\chi^{2}=15.595\), \(p=0.016\)). Electricians or plumber workers (30.0%) were the most prevalent elbow MSDs, followed by the painters (20.0%)  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multicolumn{2}{c}{**Total**} & \multirow{2}{*}{**Elbow MSDs**} & \multicolumn{3}{c}{**Sick Leave Days**} & \multicolumn{3}{c}{**Logistic Regression on Elbow**} \\ \cline{2-10}  & **MSDs** & & & & & & & & \\ \cline{2-10}  & **\(N\)** & **\(n\)** & **\%** & **\(n\)/N** & **Mean** & **SD** & **OR** & **[95\% CI]** & **\(p\)** \\ \hline \multirow{4}{*}{Occupation Welder (Ref)} & 985 & 80 & 100\% & 8.1\% & 278.7 & 149.0 & & & 0.008 * \\  & 183 & 11 & 13.8\% & 6.0\% & 315.3 & 101.7 & & & & 0.008 * \\  & 189 & 9 & 11.3\% & 4.8\% & 401.8 & 236.4 & 0.772 & 0.267 & 2.230 & 0.632 \\  & 259 & 24 & 30.0\% & 9.3\% & 263.1 & 154.3 & 1.313 & 0.538 & 3.205 & 0.549 \\  & 100 & 16 & 20.0\% & 16.0\% & 211.8 & 117.6 & 3.952 & 1.385 & 11.276 & 0.010 * \\  & 43 & 5 & 6.3\% & 11.6\% & 319.2 & 124.9 & 7.612 & 1.702 & 34.041 & 0.008 * \\  & 54 & 2 & 2.5\% & 3.7\% & 320.5 & 62.9 & 0.464 & 0.080 & 2.672 & 0.390 \\  & 157 & 13 & 16.3\% & 8.3\% & 252.0 & 104.9 & 1.386 & 0.506 & 3.796 & 0.526 \\  & \multicolumn{4}{c}{\(\chi^{2}=14.850\), \(p=0.021\) *} & & & & & & & 0.013 * \\  & \multicolumn{4}{c}{\(\chi^{2}=14.850\), \(p=0.021\) *} & & & & & & & 0.013 * \\  & \multicolumn{4}{c}{\(\chi^{2}=14.850\), \(p=0.021\) *} & & & & & & & & 0.013 * \\  & \multicolumn{4}{c}{\(\chi^{2}=13.894\), \(p<0.001\) *} & & & & & & & & &and installers (16.3%). The ratio of elbow MSDs among total MSDs was the highest in painters (16.0%). However, the mean of sick leave days for elbow MSDs was the highest in fitters (401.8 days). According to workers' age, there was a significant difference in frequency distributions between elbow MSDs and the other MSDs (\(\chi^{2}\) = 12.863, \(p\) = 0.005). The proportion of total elbow MSDs and the ratio of elbow MSDs among the total MSDs were higher in workers of 40-49 years. However, the mean of sick leave days for elbow MSDs was the highest in workers \(<\) 40 years (321.0 days). There was a significant difference in frequency distributions between elbow MSDs and the other MSDs according to MSD type (\(\chi^{2}\) = 238.894, \(p\) \(<\) 0.001). In the case of elbow MSDs, a sprain was the most prevalent type of injury (88.8%), followed by rupture (11.3%). The average number of sick leave days of sprain was 281.7 days. There was a significant difference in frequency distributions between elbow MSDs and the other MSDs according to workers' work experience (\(\chi^{2}\) = 5.198, \(p\) = 0.268). The proportion of total elbow MSDs was higher in those with \(\geq\)20 years of work experience (38.8%). The ratio of elbow MSDs among the total MSDs was higher in those with 10-19 years of work experience. The average number of sick leave days was higher in those with 1-4 years of work experience (373.3 days). According to company size, there was a significant difference in frequency distributions between elbow MSDs and the other MSDs (\(\chi^{2}\) = 5.663, \(p\) = 0.129). Companies with \(\geq\)1000 workers had the most frequent elbow MSDs (73.8%), and the possibility of elbow MSDs among total MSDs was also the highest at companies with \(\geq\)1000 workers (9.5%). The mean of sick leave days for shoulder MSDs was the highest at companies with 100-999 workers (459.3 days). Table 5 also shows the result of the binary logistic regression analysis on elbow MSDs. The factors significantly associated with elbow MSDs were company size, occupation, age, and MSD type (classification table value = 92.8%).