Christopher B Schulz1,2, Paul Rainsbury3,4, Jeremy J Hoffman5,6, Laura Ah-Kye5, Elizabeth Yang5, Raman Malhotra7, Simon Rogers3, Peter Fayers8, Tessa Fayers5. 1. Department of Ophthalmology, Portsmouth Hospitals University NHS Trust, Cosham, Portsmouth, PO6 3LY, UK. chrisschulz@doctors.org.uk. 2. Corneoplastic Unit, Queen Victoria Hospital NHS Foundation Trust, East Grinstead, RH19 3DZ, UK. chrisschulz@doctors.org.uk. 3. Department of Ophthalmology, Portsmouth Hospitals University NHS Trust, Cosham, Portsmouth, PO6 3LY, UK. 4. Department of Ophthalmology, University Hospitals Plymouth NHS Trust, Plymouth, PL6 8DH, UK. 5. Western Eye Hospital, Imperial College Healthcare NHS Trust, London, NW1 5QH, UK. 6. International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK. 7. Corneoplastic Unit, Queen Victoria Hospital NHS Foundation Trust, East Grinstead, RH19 3DZ, UK. 8. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK.
Abstract
OBJECTIVE OR PURPOSE: To develop and test a patient-reported outcome measure for assessing health-related quality of life (HRQOL) in surgically amenable epiphora. DESIGN: Questionnaire development and validation study. PARTICIPANTS: 201 patients with a cause of epiphora amenable to surgical intervention, recruited across three independent centres. METHODS, INTERVENTION OR TESTING: The watery eye quality of life (WEQOL) questionnaire was developed and refined according to defined psychometric standards. Both surgical and non-surgical participants completed WEQOL at baseline and follow-up (>3 months), along with the Lacrimal Symptom Questionnaire (Lac-Q), RAND Short Form Health Survey (SF-36) and Glasgow Benefit Inventory (GBI). Convergent validity of WEQOL was evaluated according to correlation (R > 0.40) with each of these additional tests. Responsiveness of WEQOL to intervention was evaluated according to patient-reported success. Test-retest reliability was assessed by the Bland-Altman method and intraclass correlation (ICC) in a subset of 64 participants at baseline. MAIN OUTCOME MEASURES: WEQOL construct validity, responsiveness and test-retest reliability. RESULTS: WEQOL was moderately correlated (R > 0.4) with the Lac-Q and several subscales of the SF-36 (physical role limitation, social, emotional role limitation and emotional well-being). A stronger correlation was found between the change in WEQOL at follow-up and GBI (R = 0.61). An appropriate graded response was found with a significant change in WEQOL score being observed in patients reporting successful (-28%, p < 0.0001) and partially successful surgery (-6%, p = 0.04), but not in those reporting unsuccessful surgery (+2%, p = 0.9). High test-retest reliability was observed (ICC = 0.93). CONCLUSIONS: The WEQOL questionnaire has been developed systematically according to modern psychometric standards and has been designed to evaluate the quality of life in patients with epiphora that is of a surgically amenable cause. In this study, it has demonstrated appropriate test-retest reliability, responsiveness and construct validity.
OBJECTIVE OR PURPOSE: To develop and test a patient-reported outcome measure for assessing health-related quality of life (HRQOL) in surgically amenable epiphora. DESIGN: Questionnaire development and validation study. PARTICIPANTS: 201 patients with a cause of epiphora amenable to surgical intervention, recruited across three independent centres. METHODS, INTERVENTION OR TESTING: The watery eye quality of life (WEQOL) questionnaire was developed and refined according to defined psychometric standards. Both surgical and non-surgical participants completed WEQOL at baseline and follow-up (>3 months), along with the Lacrimal Symptom Questionnaire (Lac-Q), RAND Short Form Health Survey (SF-36) and Glasgow Benefit Inventory (GBI). Convergent validity of WEQOL was evaluated according to correlation (R > 0.40) with each of these additional tests. Responsiveness of WEQOL to intervention was evaluated according to patient-reported success. Test-retest reliability was assessed by the Bland-Altman method and intraclass correlation (ICC) in a subset of 64 participants at baseline. MAIN OUTCOME MEASURES: WEQOL construct validity, responsiveness and test-retest reliability. RESULTS: WEQOL was moderately correlated (R > 0.4) with the Lac-Q and several subscales of the SF-36 (physical role limitation, social, emotional role limitation and emotional well-being). A stronger correlation was found between the change in WEQOL at follow-up and GBI (R = 0.61). An appropriate graded response was found with a significant change in WEQOL score being observed in patients reporting successful (-28%, p < 0.0001) and partially successful surgery (-6%, p = 0.04), but not in those reporting unsuccessful surgery (+2%, p = 0.9). High test-retest reliability was observed (ICC = 0.93). CONCLUSIONS: The WEQOL questionnaire has been developed systematically according to modern psychometric standards and has been designed to evaluate the quality of life in patients with epiphora that is of a surgically amenable cause. In this study, it has demonstrated appropriate test-retest reliability, responsiveness and construct validity.