Table 3

Incidence of pterygium in smokers and non-smokers 

Propensity-score-matched analysis (n=181 094)
Never-smokerSmoker
(n=90 547)Past smoker (n=26 152)Current smoker (n=64 395)
Total follow-up (PYs)826 493238 697584 895
No. of pterygium538913422556
Incidence (no./1000 PYs, 95% CI)6.55.64.4
Age-adjusted HR (95% CI)1 (reference)0.85 (0.80 to 0.90)0.68 (0.65 to 0.71)
P Value<0.001<0.001
P for trends<0.001
  • PYs, person-years.