Table 3.

Logistic regression analysis of factors with a possible association with pterygium

	Any pterygium*	Odds ratio (95% CI)	Bilateral pterygium†	Odds ratio (95% CI)
	Odds ratio	Adjusted odds ratio	Odds ratio	Adjusted odds ratio
Age (years)
Age per 10	1.41 (1.09,1.8)	1.36 (1.04,1.78)	1.90 (1.20,3.01)	1.78 (1.10,2.89)
Gender
Male	0.83 (0.55,1.26)	0.83 (0.53,1.3)	0.92 (0.47,1.81)	0.98 (0.48,2.02)
Female	1 (–)	1 (–)	1 (–)	1 (–)
Outdoor job history‡
+	1.47 (0.95,2.28)	1.22 (0.77,1.93)	1.95 (0.98,3.88)	1.43 (0.69,2.94)
−	1 (–)	1 (–)	1 (–)	1 (–)
Smoking history
+	0.88 (0.49,1.60)	1.14 (0.60,2.18)	0.75 (0.26,2.13)	1.00 (0.33,3.09)
−	1 (–)	1 (–)	1 (–)	1 (–)

CI = confidence interval.

^*Any pterygium is defined as pterygium in either eye or both eyes.

^†Bilateral pterygium is defined as pterygium in both eyes.

^‡Outdoor jobs included full-time and part-time outdoor jobs during the lifetime of the subject.