Evaluating empowerment in genetic counseling using patient reported outcomes.

1547Background: Despite the demand for cancer genetic services, patient-derived benefits remain poorly captured due to a paucity of validated tools. The Genetic CounsellingOutcome Scale (GCOS-24), a genetics-specific Patient Reported OutcomeMeasure ( PROM), has been adapted to evaluate our local cancer genetic service (CGS). We aim to evaluate the psychometric properties of GCOS-24 using Rasch analysis. Methods: 155 patients who attended CGS at National Cancer Centre Singapore (May 2016-2017) were recruited. The questionnaire was interviewer-administered pre- and post-counselling. Responses were subjected to Rasch analysis, comparing individual Rasch item scores pre and post. Multiple regression analysis was used to assess the association of baseline characteristics with changes in scores. Results: GCOS-24 questionnaire displayed good precision (person separation index > 2.0) and targeting (difference between person and item means < 1.0). Cognitive Control [post-intervention: median 1.23 (IQR -0.3-6.2); ...