## 3 Results
### Logistic Regression Analysis on Self-Reported Overall Fatigue and Musculoskeletal Pains
#### 3.4.5 Logistic Regression Analysis on Pain Complaints in Any One Area  
The results of logistic regression on pain in any one area are presented in Table 15. Four hundred and forty six subjects were classified into two groups depending on the pain complaints in any one area. The power of explanation of the model was acceptable (Nagelkerke value = 0.167) and the model seems to fit quite well (\(\chi^{2}\) = 2.130, significance value = 0.952). The overall rate of correct classification (classification accuracy) was estimated as 74.4%. Gender (\(p\) = 0.012), work experience (\(p\) = 0.002), working hours per week (\(p\) = 0.015), and exposure to high temperature (\(p\) < 0.001) were the risk factors for pain in any one area. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multirow{2}{*}{**N**} & \multirow{2}{*}{**\%**} & \multirow{2}{*}{**B**} & \multirow{2}{*}{**\(p\)-Value**} & \multirow{2}{*}{**Exp(B)**} & \multicolumn{2}{c}{**95\% C.I. for EXP(B)**} \\ \cline{5-8}  & & & & & & **Lower** & **Upper** \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Gender \\ Male(ref) \\ Female \\ Work experience \\ \end{tabular} } & \multirow{2}{*}{363} & \multirow{2}{*}{81.4\%} & \multirow{2}{*}{0.702} & \multirow{2}{*}{0.012 *} & \multirow{2}{*}{2.018} & \multirow{2}{*}{1.168} & \multirow{2}{*}{3.487} \\  & & & & & 0.002 * & & \\ \cline{1-1} \cline{5-8}  & 85 & 19.1\% & & & & & \\ \cline{1-1} \cline{5-8}  & 70 & 15.7\% & 1.427 & 0.001 * & 4.165 & 1.812 & 9.570 \\ \cline{1-1} \cline{5-8}  & 291 & 65.2\% & 1.102 & 0.002 * & 3.009 & 1.488 & 6.082 \\ \cline{1-1} \cline{5-8}  & Work hours & & & 0.015 * & & & \\ \cline{1-1} \cline{5-8}  & 272 & 61.0\% & & & & & \\ \cline{1-1} \cline{5-8}  & 174 & 39.0\% & 0.591 & 0.011 * & 1.805 & 1.147 & 2.842 \\ \cline{1-1} \cline{5-8}  & High temperature & & & & \(<\)0.001 * & & & \\ \cline{1-1} \cline{5-8}  & 280 & 62.8\% & & & & & \\ \cline{1-1} \cline{5-8}  & 56 & 12.5\% & 0.024 & 0.950 & 1.024 & 0.487 & 2.151 \\ \cline{1-1} \cline{5-8}  & \(\geq\)4 & 110 & 24.7\% & 1.372 & \(<\)0.001 * & 3.943 & 2.394 & 6.495 \\ \cline{1-1} constant & & & & \(-\)2.761 & \(<\)0.001 * & 0.063 & & \\ \hline \hline \end{tabular}
* * Significant at 0.05, Note: ref = reference, C.I. = confidence interval.  
\end{table} 
Table 14: Results of logistic regression on lower limb pain. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multirow{2}{*}{**N**} & \multirow{2}{*}{**\%**} & \multirow{2}{*}{**B**} & \multirow{2}{*}{**\(p\)-Value**} & \multirow{2}{*}{**Exp(B)**} & \multicolumn{2}{c}{**95\% C.I. for EXP(B)**} \\ \cline{5-8}  & & & & & & **Lower** & **Upper** \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Fumes and dust \\ \textless{2} (ref) \\ 2–4 \\ \end{tabular} } & \multirow{2}{*}{71} & \multirow{2}{*}{15.9\%} & \multirow{2}{*}{0.177} & \multirow{2}{*}{0.725} & \multirow{2}{*}{1.193} & \multirow{2}{*}{0.445} & \multirow{2}{*}{3.197} \\  & 102 & 22.9\% & & & & 0.021 * & \\ \cline{1-1} \cline{5-8}  & 82 & 18.4\% & \(-\)1.423 & 0.071 & 0.241 & 0.051 & 1.132 \\ \cline{1-1} \cline{5-8}  & 197 & 44.2\% & 0.529 & 0.183 & 1.697 & 0.779 & 3.699 \\ \cline{1-1} \cline{5-8}  & constant & & & \(-\)2.698 & \(<\)0.001 & 0.067 & & \\ \hline \hline \end{tabular}  
* * Significant at 0.05, Note: ref = reference, C.I. = confidence interval.  
\end{table} 
Table 15: Results of logistic regression on pain complaints in any one area. Complaints of pain in any one area among females was 2.018 times more likely than for males. Complaints of pain in any one area among those who have three to five years of work experience was 4.165 times more likely than those who have less than three years of work experience. Complaints of pain in any one area among those who have more than five years of work experience was 3.009 times more likely than those who have less than three years of work experience.