Abstract
Abstract: :
Purpose: The CLDEQ short–form demonstrates good accuracy in predicting a doctor’s diagnosis of contact lens–related dry eye (Nichols and coworkers, Cornea 2003;21:469–475). The purpose of this report is to assess the reliability of patient–reported responses to questions on the CLDEQ short–form. Methods: The CLDEQ short–form was administered on two occasions to a sample of contact lens wearers. The survey consists of three main questions predictive of contact lens–related dry eye: dryness, light sensitivity, and a self–perception question. For dryness and light sensitivity, the subject is asked the frequency of the symptom, followed by the intensity of the symptom at three times throughout the day: morning, midday, and evening. The responses to the questions are scored by multiplying the frequency by the average intensity, which are then used in the algorithm from logistic regression: p (contact lens–related dry eye | score = self–diagnosis and dryness) = (1 + e 2.72–1.26(self–perception)– 0.18(dryness) + 0.10(photophobia))–1. The intraclass correlation coefficient and Bland–Altman method of 95% limits of agreement were used to assess the test–retest reliability of the composite scale. Results: One hundred eighteen contact lens wearers were included (median age = 26 years, 64% female). The mean difference between administrations was 39 ± 29 days. The intraclass correlation coefficient for the composite score was 0.69 (95% confidence interval = 0.55 to 0.78). The mean difference in the composite CLDEQ score between visits was –0.01 ± 0.73, which did not statistically differ from zero (t = –0.21, p = 0.83). The 95% limits of agreement were –1.44 to 1.41. Test–retest reliability was not related to the overall score (r = 0.12, p = 0.19), patient age (r = 0.01, p = 0.93), days between administrations (r = 0.11, p = 0.27), or gender (mean difference between genders = 0.19 ± 0.72, t= 1.53, p = 0.13). Conclusions: There is moderate self–reported test–retest reliability in patients with contact lens–related dry eye. The instrument should be administered on more than one occasion before disease classification can be made.
Keywords: contact lens • quality of life • lacrimal gland