Table 4.

Subgroup Analysis of Associations Between Weekend Outdoor Hours Per Day and the Risk of Cataract Surgery During the Follow-Up

	Weekend Outdoor Hours Per Day
	3–4 vs. ≤2	5–10 vs. ≤2	10+ vs. ≤2		P for
Factors	HR (95% CI)	HR (95% CI)	HR (95% CI)	P for Trend	Interaction
Baseline age (y)					0.293
45–49	0.96 (0.80–1.16)	0.97 (0.81–1.17)	0.90 (0.71–1.16)	0.486
50–54	0.91 (0.82–1.03)	0.94 (0.83–1.05)	0.89 (0.76–1.05)	0.185
55–59	0.92 (0.85–1.00)	0.92 (0.84–1.00)	0.96 (0.85–1.07)	0.153
60–65	0.97 (0.91–1.03)	0.92 (0.86–0.99)a	0.90 (0.81–0.99)a	0.002
Sex					0.107
Male	0.97 (0.89–1.06)	0.95 (0.88–1.03)	0.95 (0.86–1.05)	0.217
Female	0.94 (0.89–0.99)a	0.92 (0.87–0.97)a	0.87 (0.79–0.96)a	<0.001
BMI					0.233
Normal	0.91 (0.85–0.98)a	0.93 (0.86–1.00)a	0.92 (0.82–1.03)	0.053
Overweight	0.98 (0.91–1.06)	0.90 (0.83–0.97)a	0.90 (0.81–1.00)a	0.004
Obesity	0.94 (0.85–1.04)	0.94 (0.85–1.05)	0.90 (0.79–1.03)	0.116
Smoker (current + past)					0.939
Yes	1.09 (0.88–1.34)	0.92 (0.74–1.13)	0.83 (0.64–1.08)	0.107
No	0.94 (0.90–0.98)a	0.92 (0.88–0.97)a	0.92 (0.86–0.98)a	0.001
Alcohol consumption per week					0.110
<14 drinks	0.96 (0.91–1.01)	0.93 (0.88–0.99)a	0.93 (0.86–1.00)	0.008
≥14 drinks	0.92 (0.84–1.00)	0.91 (0.83–0.99)a	0.88 (0.77–1.01)	0.003
Physical activity (sessions/wk)					0.724
<5	0.83 (0.75–0.93)a	0.82 (0.73–0.92)a	0.85 (0.72–1.00)	0.002
>5–9	0.97 (0.89–1.05)	1.00 (0.92–1.08)	0.95 (0.84–1.07)	0.597
>9–14	0.94 (0.86–1.03)	0.89 (0.81–0.97)a	0.89 (0.78–1.02)	0.008
>14	1.01 (0.92–1.10)	0.96 (0.88–1.05)	0.94 (0.84–1.06)	0.115

^aIndicates P value < 0.05.