[BMJ Publishing Group Ltd and British Thoracic Society British Thoracic Society Winter Meeting 2017, QEII Centre Broad Sanctuary Westminster London SW1P 3EE, 6 to 8 December 2017, Programme and Abstracts - ()] Diagnosing and treating pulmonary vascular disease - S49 Elicitation of disutility values associated with the mode of administration of drugs acting on the prostacyclin pathway in pulmonary arterial hypertension (pah)