What Is a Flare? The Manitoba Living With IBD Study.

Background: Flare is a poorly defined term used by patients and clinicians to indicate inflammatory bowel disease (IBD) status. This study aimed to evaluate the validity of a single-item 7-point flare indicator relative to other measures of disease flare.

Methods: The longitudinal Manitoba Living with IBD Study followed persons with IBD for 1 year; they completed biweekly online surveys and provided 3 stool samples. Disease flare on a single-item flare indicator with 7 possible responses developed for the study was defined by report of symptoms as "moderately" or "much" worse. The flare indicator was evaluated against 5 measures of disease activity: fecal calprotectin score (FCAL), a 2-point disease status indicator, a 4-point flare certainty indicator, the IBD Symptom Index short form (SIBDSI), and the short form IBD Questionnaire (SIBDQ). Participants in a flare, based on the 7-point measure, were matched to a nonflaring participant, and a stool sample was collected.

Results: Of the 155 IBD participants, almost half (n = 74) experienced a flare. Of those who flared, 97.0% endorsed active IBD on the 2-point indicator (controls 42.5%; P < .001); 91.9% endorsed active IBD on the 4-point certainty indicator (controls 32.9%; P < .001); 90.5% endorsed active disease on the SIBDSI (controls 34.2%; P < .001); and 48.5% had an elevated FCAL (controls 34.3%; P < .05). The mean SIBDQ was lower for the flare group compared with controls (43.9 [SD 11.1] vs 58.3 [SD 8.5]; P < .001), indicating worse disease.

Conclusions: The 7-point flare indicator robustly identified symptomatic flares. This patient self-report indicator reflected meaningful changes in more complex clinical indices and had only weak concordance with the presence of inflammation.