Validation of the 5-Item Dry Eye Questionnaire (DEQ-5): Discrimination across self-assessed severity and aqueous tear deficient dry eye diagnoses

Abstract

Purpose

To validate a subset of Dry Eye Questionnaire (DEQ) items that discriminate across self-assessed severity and various diagnoses of dry eye (DE).

Methods

Subjects (n = 260) in 2 studies received a clinical DE diagnosis, completed the 6-page DEQ and self-assessment of DE severity (SA-Sev). SA-Sev ratings were: 46 Severe, 107 Moderate, 77 Mild, and 46 None. Dry eye diagnoses were: 48 asymptomatic controls (C), 155 non-SS KCS, and 57 Sjögren Syndrome (SS). All DEQ items were correlated to SA-Sev by Spearman. Groups of highly correlated DEQ items were tested to discriminate SA-Sev; and the subset tested to distinguish across DE diagnosis.

Results

The DEQ-5 comprises: frequency of watery eyes (r = 0.48), discomfort (r = 0.41), and dryness (r = 0.35), and late day (PM) intensity of discomfort and dryness (r = 0.42, 0.36) all significantly correlated to SA-Sev (p < 0.01). Mean DEQ-5 scores by SA-Sev: Severe 14.9 ± 2.3, Moderate 11.4 ± 3.3, Mild 8.6 ± 3.1 and None 2.7 ± 3.2 (ANOVA, p < 0.0001) and by DE diagnosis: C 2.7 ± 2.9, non-SS KCS10.5 ± 4.5 and SS14.0 ± 3.4, differing significantly overall (Z = −8.6, p = 0.000) and between diagnoses (X² = 116.3, p = 0.000). Watery eyes were reported primarily by non-SS KCS. Proposed screening criteria for the DEQ-5 are >6 for DE and >12 for suspected SS.

Conclusions

The DEQ-5, the sum of scores for frequency and PM intensity of dryness and discomfort plus frequency of watery eyes, effectively discriminated across self-assessed severity ratings and between patients with DE diagnoses. These results indicate that DEQ-5 scores >6 suggest DE and scores >12 may indicate further testing to rule out SS–DE.

Introduction

Over the past decade, ocular surface symptoms have taken on an increasingly important role in the research, treatment and management of dry eye [1], [2], [3], [4], [5]. Whereas the previous definition of dry eye emphasized signs of ocular surface damage and dysfunction of the lacrimal system [6], the more recent definition developed by the 2007 Dry Eye Workshop (DEWS) redrafted the definition with symptoms as a more central feature of the disease [7]. In mild and moderate cases of dry eye, symptoms of discomfort and dryness are often the predominant feature of the condition and these symptoms are reported by between 30 and 80% of sufferers, depending on diagnosis [8], [9]. Many studies have shown a lack of agreement between symptoms and clinical signs of dry eye [10], [11], [12], which is likely based on the few positive clinical signs in mild to moderate dry eye patients [9]. In a cross-sectional study on the relationship between dry eye signs and symptoms, the primary clinical test that distinguished dry eye from asymptomatic controls was tear break-up time [9]. That study also showed that the late day intensity of discomfort and dryness correlated with nearly all ocular signs as well or better than frequency of or morning intensity of symptoms. Thus, symptom assessment plays a large role in dry eye diagnosis and management and warrants further exploration.

A number of questionnaires have been developed to capture dry eye symptoms for many purposes; to explore the epidemiology of the condition [13], [14], [15], [16], [17], [18], [19], [20], for diagnosis [21], to assess treatment effects and to measure its impact on quality of life [22], [23], [24]. The full Dry Eye Questionnaire (DEQ) is unique in that it measures a number of symptoms in four dimensions: frequency, intensity in the morning (AM intensity), intensity late in the day (PM intensity) and degree of bother [9]. Tracking changes in symptoms over the day appears warranted given current hypotheses on the etiology of dry eye. Many clinical investigations and the recent DEWS report have identified tear instability and hyperosmolarity as core mechanisms of dry eye [7]. These conditions should manifest themselves in the open eye condition and would be expected to drive an increase in symptoms over the day [8], [9], [25]. Previous DEQ studies have shown late day symptoms of dryness and discomfort exhibit the highest responsiveness among subjects who report change in global status of dry eye under test–retest conditions [26]. The DEQ habitual symptom items are also free of confounding by the time of day at which the questionnaires are administered [27]. This is particularly important to establish since a number of DEQ questions focus on recall of symptom intensity at various times of day.

The purpose of this analysis was to develop and validate a short subset of DEQ items that discriminate across self-assessed severity and various diagnoses of dry eye in order to determine scoring criteria that identify patients who may benefit from further clinical testing for dry eye conditions.