Disease monitoring strategies in inflammatory bowel diseases: What do we mean by “tight control”?

Table 2 Intervals of clinical, biomarker, and endoscopic assessment in the treat-to-target and tight control framework

	Active disease/at flare	Clinical remission
Crohn’s disease
Clinical evaluation (PRO, CDAI, HBI indices)	3 mo [STRIDE and CALM protocol][28,13]	6-12 mo [STRIDE][28] 3 mo [CALM protocol][13]
Endoscopic evaluation	6-9 mo after therapy initiation [STRIDE][28]	Based on screening recommendations in deep remission Prompted by clinical symptoms or (consecutive) biomarker positivity – FCAL[52,53]
Biomarker evaluation (CRP and FCAL)	3 mo (FCAL + CRP) [CALM protocol][13,94] Approximately 12-14 wk after therapy initiation (CRP)[95,96] Approximately 14 wk after therapy initiation (FCAL)[94,97,98]	3 mo (FCAL + CRP) [CALM protocol][13] (2)-3 mo (FCAL)[52,53] 3 mo (CRP1)[99]
Ulcerative colitis
Clinical evaluation (PRO, CDAI, HBI indices)	3 mo [STRIDE][28]	6-12 mo [STRIDE][28]
Endoscopic evaluation	3-6 mo after therapy initiation [STRIDE][28]	Based on screening recommendations in deep remission Prompted by clinical symptoms or (consecutive) biomarker positivity – FCAL[52,53]
Biomarker evaluation (CRP and FCAL)	Approximately 10 wk after therapy initiation (FCAL)[100]	(2)-3 mo[51-53,101]

¹Using C-reactive protein alone has only moderate predictive value in identifying relapse in patients with clinical remission. PRO: Patient reported outcome; CDAI: Crohn’s Disease Activity Index; HBI: Harvey Bradshaw Index; CRP: C-reactive protein; FCAL: Fecal calprotectin; STRIDE: Selecting therapeutic targets in inflammatory bowel disease.