Purpose: To clinically validate and ascertain the repeatability of a short questionnaire for dry eye syndrome (DES), consisting of two questions pertaining to symptoms (dryness and irritation) and one question regarding previous history of clinically diagnosed DES.
Design: Clinical validation study with repeated assessments.
Methods: A short questionnaire for DES was administered to participants of two large cohort studies, the Women's Health Study (WHS) and the Physicians' Health Study (PHS). A supplementary questionnaire comprising 16 questions pertaining to symptoms was mailed to a subset of 450 WHS and 240 PHS participants, selected so that a third of these subjects had DES based on their response to the short questionnaire. Repeatability of the dryness and irritation symptom questions was ascertained using intraclass correlation coefficient (ICC). Standardized ophthalmologic examination was performed on 53 subjects. Sensitivity and specificity of the short questionnaire was determined using a combination of clinical tests to define clinical DES.
Results: An ICC of 0.75 for dryness and 0.65 for irritation was found between subsequent measurements. Participants' responses to the dryness and irritation questions were highly correlated (r = 0.75) with a score derived from responses to the longer 16-symptom questionnaire. The short questionnaire for DES had a sensitivity of 77% and specificity of 83% when cutoff point for clinical DES was Schirmer 1 value </=10 mm or tear breakup time <10 seconds.
Conclusion: The short questionnaire for DES is a sensitive and repeatable tool that is easy to administer in large epidemiologic research studies as well as clinical research.