Association of primary diagnosis versus risk factors (reduced model). (i) Primary diagnosis: OAG versus OH. (ii) Age, cup-to-disc ratio, and mean deviation are continuous variables, and the others are categorical. Age was estimated in every one-year increment, cup-to-disc ratio in every 0.1-unit increment, and mean deviation in every 1 dB unit of worsening. Categorical variables were estimated as follows: visual field overall (abnormal versus normal, localized notching/thinning (Yes versus No), location (Quebec/Atlantic versus Ontario), smoking (Yes versus No). (iii) Odds ratio, 95% confidence interval. (1) OR = 1 implies a specific risk factor is equally likely in both OAG and OH groups, OR >1 implies more likely in OAG, and OR < 1 implies more likely in OH.