Table 1.

The pterygium data containing 29 studies with 8 risk factors. The effect size is log odds ratio with within-study standard error in parentheses. The blank entries indicate that the risk factors are unavailable from the corresponding studies.

	Risk factor
Study	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
1	−0.08 (0.34)
2						1.54 (0.10)
3	0.28 (0.17)	0.53 (0.10)	0.53 (0.13)
4	0.45 (0.11)					0.41 (0.10)		0.97 (0.23)
5	0.30 (0.40)
6				0.12 (0.40)	0.48 (0.70)
7	1.40 (0.23)
8	0.39 (0.13)	0.05 (0.13)
9	0.55 (0.22)	−0.04 (0.26)
10	3.04 (1.03)
11	1.95 (0.40)	1.21 (0.42)		0.67 (0.36)	−1.34 (0.34)		0.12 (0.31)
12	1.10 (0.30)
13	2.03 (0.39)			−0.69 (0.21)	−1.14 (0.38)		−1.64 (0.21)	2.99 (0.74)
14	0.83 (0.09)	0.11 (0.09)	0.91 (0.09)		−0.58 (0.12)	1.14 (0.13)
15	0.41 (0.22)
16		−0.20 (0.24)				1.73 (0.18)
17	0.42 (0.15)	−0.11 (0.25)	0.38 (0.21)	0.22 (0.15)	−0.64 (0.15)		−0.52 (0.37)
18	0.63 (0.12)	0.03 (0.05)	1.24 (0.24)
19	0.89 (0.08)	−0.08 (0.07)		1.70 (0.08)	−0.17 (0.08)		−0.06 (0.14)
20	0.39 (0.22)	−0.13 (0.30)
21	0.90 (0.30)							0.85 (0.49)
22	−0.48 (0.25)	0.31 (0.25)	0.87 (0.20)
23								0.66 (0.26)
24				−0.46 (0.72)			−0.73 (0.52)
25	0.76 (0.34)	−0.48 (0.55)	1.05 (0.33)
26		0.03 (0.11)	0.19 (0.09)
27	1.16 (0.36)	0.53 (0.23)	0.83 (0.25)
28	0.12 (0.03)	0.14 (0.20)	1.43 (0.28)			1.43 (0.22)
29	0.41 (0.09)	−0.26 (0.10)	0.46 (0.09)

Risk factors: (1) occupation type; (2) smoking status; (3) education attainment; (4) use of hat; (5) use of spectacles; (6) area of residence; (7) use of sunglasses; and (8) latitude of residence.