Table 5.

Primary and Secondary Outcome Measures. Note: Primary and secondary outcomes will be measured at enrollment (T1), at the time of transfer to adult care (T2), and at the end of the study period (1–2 years after transfer) (T3), unless otherwise specified

Domain	Measure	Timing of administration
Primary outcome
Disability and function	IBD-DI [26, 27]	T1, T2, T3
Secondary outcomes
Transition readiness	Transition Readiness Assessment Questionnaire (TRAQ) [28] Transition Success Scores (TSS)	T1, T2, T3
Bio-psychosocial risk	Pediatric IBD INTERMED [24]	T1, T2, T3
Disease-related knowledge	IBD-KID2[29]	T1, T2, T3
Quality of life	IBDQ-32[57]	T1, T2, T3
Self-efficacy	IBD Self-Efficacy Scale—Adolescent (IBD-SES-A) [58]	T1, T2, T3
Mental Health	Patient Health Questionnaire-9 (PHQ-9) Generalized Anxiety Disorder-7 (GAD-7)	T1, T2, T3
Disease activity	Physician global assessment (PGA) of disease activity Modified Harvey Bradshaw Index (HBI) Assessment for CD Activity [44] Pediatric Ulcerative Colitis Activity Index (PUCAI) for UC Activity [45] Fecal calprotectin (at enrollment and study termination only)	T1, T2, T3 T1, T3
Health services utilization	Emergency department visit after 18th birthday (yes/no) Number of emergency department visits after 18th birthday Hospitalization after 18th birthday (yes/no) Number of outpatient visits to GI after 18th birthday	T3