Identifying patient-valued outcomes for use in early phase trials of ocular surface disease interventions.

BACKGROUND: Patient-reported outcomes (PROs) can be used to evaluate the impact of dry eye symptoms (DES) on daily life. Early-phase clinical trials provide an opportunity to evaluate PRO strategies. Existing measures identified through systematic review omitted important concepts that mattered to patients. The aim of our work was to develop a conceptual map of DES and assess the relative importance of identified concepts. METHODS: Web-based group concept mapping software was used to develop a conceptual map. This semi-quantitative mixed-methods approach consists of three stages 1) statement generation, 2) thematic sorting, 3) rating of statements for importance [1 (not important), 2 (important), 3 (very important)] and relevance [1 (not my experience), 2 (sometimes my experience); 3 (definitely my experience)]. Thirty-nine participants were recruited from two UK-based patient support groups (British Sjogren's Syndrome Association, PemFriends). Three withdrew, two for health reasons and one struggled with the web-based format. RESULTS: 125 statements and six thematic clusters were generated. The Environmental Impacts cluster scored highest for importance (2.45), followed by Pain and Discomfort (2.35), Eye Treatments (2.32), Daily Impact (2.07), Psychosocial Issues (1.78) and Miscellaneous (1.78). Mapping statements against existing PRO measures confirmed a number of important missing issues including the impact of 'UV levels' (2.50), hot dry weather (2.33), the temporal aspects of pain (2.64), and issues with night-driving (2.59). CONCLUSIONS: Group concept mapping identified important issues for people living with DES not currently captured by existing PROs, highlighting the need for additional PRO items to be considered for use in clinical trials.