The instrument consists of 6 questions related to dry eyes (gritty sensation, burning, etc).
Responses:
(1) never
(2) rarely
(3) sometimes
(4) often
(5) all of the time
Definition of positive vs negative for symptom:
(1) Definition 1 for positive: responses of sometimes, often or all of the time; else negative
(2) Definition 2 for positive: responses of often or all of the time; else negative
Groups recognized with Definition 1:
(1) no symptoms "positive"
(2) 1 or 2 symptoms "positive", usually including eyes feeling gritty
(3) 2 or more symptoms "positive", predominantly eyes burning and with little crusting, typically associated with insufficient tear flow
(4) 2 or more symptoms "positive", predominantly lashes crusting, typically associated with blepharitis
