Table 4

Reproducibility of IBD-Control summary scores for stable patients

Instrument score (scale)Mean difference (Visit 2—Visit 1)SD of differenceIntraclass correlation (95% CI)
(A) Patients returning at 2 weeks (test-retest group)*
 IBD-Control-8 subscore (0–16)−0.451.810.97 (0.90 to 0.99)
 IBD-Control-VAS (0–100)+2.259.790.96 (0.88 to 0.99)
(B) Patients returning for a scheduled clinic visit (routine care group)†
 IBD-Control-8 subscore (0–16)0.003.720.87 (0.71 to 0.94)
 IBD-Control-VAS (0–100)−0.5623.000.81 (0.58 to 0.91)
  • *Data for 13 patients responding ‘not changed’ to the IBD-Control transition question (‘Over the past 2 weeks have your bowel symptoms been getting worse, getting better or not changed’) and with stable UK-IBD-Qol total scores (<10-point change between two visits).

  • †Data for 32 patients with a stable (unchanged) physician global assessment rating between two visits (mean interval between visits 131 days).

  • Two-way fixed effects model for consistency, p<0.001.

  • IBD, inflammatory bowel disease; QoL, quality of life; VAS, visual analogue scale.