# Impact of Urbanization and Sunlight Exposure on Cataract Incidence
## 3 Results  
Table 2 reports the characteristics of the 396,321 insured included in the analysis. Among them, 48.85% were male, 51.15% were female. Most of them were age between 40 and 49 (40.76%). Those who worked in the industry were the most common occupation (34.64%) in this study. In terms of residence locations, the majority included in the analysis live in high and medium urbanized areas (57.91%).  
Results of the logistic regression (Table 3) shows that when controlled for confounding factors, such as demographics (age, gender, occupation) and presence of comorbidities (such as diabetes, hypertension, chronic kidney disease), those who live in highly urbanized areas or expose for a longer duration of sunlight exposure are more likely to suffer from senile cataract (\(p<0.001\)).  
The analysis also demonstrates that, compared to the age group between 40 and 49, higher ages were associated with a significantly higher incidence of senile cataracts. Similarly, being female, a longer duration of sunlight exposure, and the presence of comorbidities (such as diabetes, CKD, and hypertension) were all associated with a significantly higher incidence of senile cataracts.  
In terms of urbanization of residents' living areas, compared to those who live in medium urbanized areas, those who live in high urbanized areas are associated with a significantly higher incidence of senile cataract while those who live in less and low urbanized areas experience a significantly lower incidence of senile cataract.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{2}{c}{**Senile Cataract**} & \multicolumn{2}{c}{**Without Senile Cataract**} \\  & \multicolumn{2}{c}{**(N = 3080)**} & \multicolumn{2}{c}{**(N = 393,241)**} \\ \cline{2-5}  & **N** & **\%** & **N** & **\%** \\ \hline Gender & & & & \\ Male & 1455 & 0.37\% & 192,138 & 48.48\% \\ Female & 1625 & 0.41\% & 201,103 & 50.74\% \\ Age & & & & \\
40–49 & 80 & 0.02\% & 161,468 & 40.74\% \\
50–59 & 325 & 0.08\% & 95,131 & 24.00\% \\
60–69 & 1084 & 0.27\% & 72,006 & 18.17\% \\
70–79 & 1256 & 0.32\% & 48,570 & 12.26\% \\
80+ & 335 & 0.08\% & 16,066 & 4.05\% \\ Occupation & & & & \\ School teachers/staff & 246 & 0.06\% & 23,082 & 5.82\% \\ Industry employees & 705 & 0.18\% & 136,564 & 34.46\% \\ Government employee & 47 & 0.01\% & 9379 & 2.37\% \\ Self-employed & 0 & 0.00\% & 4 & 0.00\% \\ Vocational union staff & 351 & 0.09\% & 86,437 & 21.81\% \\ Foreign seamen & 0 & 0.00\% & 10 & 0.00\% \\ Farmers & 854 & 0.22\% & 74,850 & 18.89\% \\ Fishermen/Seamen & 68 & 0.02\% & 8029 & 2.03\% \\ Dependents-deceased public & 6 & 0.00\% & 689 & 0.17\% \\ servants & & & & \\ Low income & 24 & 0.01\% & 2535 & 0.64\% \\ Veterans & & 10 & 0.00\% & 823 & 0.21\% \\ Others (e.g., religious workers, etc.) & 766 & 0.19\% & 50,738 & 12.81\% \\ Urbanization & & & & \\ Highly urbanized & 904 & 0.23\% & 116,509 & 29.40\% \\ High urbanized & 840 & 0.21\% & 111,235 & 28.07\% \\ Medium urbanized & 398 & 0.10\% & 59,742 & 15.07\% \\ Low urbanized & 459 & 0.12\% & 56,903 & 14.36\% \\ Remote areas & 479 & 0.12\% & 48,852 & 12.33\% \\ \hline \hline \end{tabular}
\end{table}
Table 2: Descriptive Analysis (N = 396,321).  
Table 4 further demonstrates the odds ratios of different levels of urbanization, compared to remote areas, on the incidence of senile cataracts. For example, the OR of highly urbanized areas over the remote areas is 1.41, which means those living in highly urbanized areas have a 1.41 times higher chance of developing a senile cataract than those living in remote areas.