Table II.

Time trade-off (TTO) and standard gamble (SG) studies in IBD

Study	Study Type	Study Population and Sample Size	Study Aim
McLeod RS et al.100	TTO	20 pre- & post-colectomy UC patients 93 post-colectomy UC patients	Evaluate perceived quality of life by UC patients pre-colectomy and post-colectomy surgery
Kennedy ED et al.101	SG	65 CD patients	Determine if CD patients value absolute reduction in post-operative disease recurrence attributable to 5-ASA therapy*
Arseneau KO et al.102	SG	32 CD patients 15 non-CD patients	Determine utilities for CD patients for varying perianal fistula treatments†
Arseneau KO et al.99	TTO	48 UC patients	Determine utilities for steroid-refractory UC for colectomy versus varying medical therapy†
Byrne CM et al.103	TTO/SG	41 CD patients 92 colorectal surgeons 74 gastroenterologists	Compare preferences for surgical intervention in CD between patients, gastroenterologists and surgeons
Waljee AK et al.104	TTO	150 non-UC patients 150 UC patients 150 UC post-colectomy patients	Evaluate differences in utility of active UC versus post-colectomy state
Waljee AK et al.105	SG/TTO	150 UC patients 150 post-colectomy UC patients	Evaluate discount rate used by UC patients when evaluating colectomy
Brown LK et al.106	TTO	17 physicians 150 post-colectomy UC patients 69 moderate UC patients	Compare physician and patient preferences for active UC versus colectomy

^*further discussion in letter to editor¹⁰⁷

^†utilities determined for Markov modeling