Article Text
Abstract
Introduction Although a range of disease activity measures and QoL questionnaires is available for IBD, none has found a place in routine clinical practice. This project aimed to develop a tool for capturing disease control from the patient's perspective with measurement properties appropriate for routine clinical practice.
Methods Phase I: Systematic review of existing PROMS, patient focus groups and a steering group to define domains and items for the “IBD-Control”. Instrument comprises 13 questions items plus a visual analogue scale (VAS, 0–100) for overall control. Phase II: Prospective validation, patient completion of IBD-Control, QoL questionnaire (UK-IBD-Q), EuroQol (EQ5D), Hospital Anxiety & Depression Score (HADS); clinician assessment (blinded to questionnaire) recording disease activity (Harvey Bradshaw Index, HBI; or Simple Clinical Colitis Activity Index, SCCAI), global clinician assessment (remission; mild; moderate; severe), Montreal Classification, treatment history. Ongoing longitudinal survey (serial questionnaires).
Results 194/200 returned baseline surveys (CD, n=107; UC, n=87). Study population (CD, UC): Age (mean): 41; 48 yrs. Disease duration (mean): 10.5; 10.7 yrs. Prev. Surgery (%): 50%; 3.4%. Immunosuppressants (%): 49.5%; 27.6%. Biologics (%): 22.4%; 8.0%. Disease activity (mean [SD] HBI; SCCAI): 5 [5]; 4 [3]. Measurement properties of IBD-Control: Completion time (mean [SD]): 1 min 15 s [25s]; Internal consistency: Cronbach's α for all 13 items: 0.838; for sub-group of 8 questions (IBD-Control-8): 0.841. Strong correlation between IBD-Control-8 sub-score and IBD-Control-VAS (r=0.79). Test-retest reliability for stable patients (Baseline vs 2 week repeat, no change): IBD-Control-8, 15.8 vs 15.6; p=0.73; IBD-Control-VAS, 65.5 vs 68.0, p=0.33. Validity: Moderate-to-strong correlations between IBD-Control-8 subscore and IBD-Control-VAS vs disease activity, UK-IBD-Q and global health state (utility) with r values 0.56 to 0.84. Discriminant validity (mean scores for remission, mild, moderate, severe): ANOVA p<0.01. Sensitivity to change: (analysis of first 53 follow-ups): No significant changes for stable patients; moderate-to-large responsiveness statistics for IBD-Control-8 and IBD-Control-VAS: (Effect sizes: 0.4–1.6).
Conclusion The IBD-Control shows promise as a rapid (<2 min), reliable, valid and sensitive instrument for measuring overall disease control from the patients perspective. Unlike existing PROMS, its ease-of-use and generic applicability make it a candidate for use in routine practice as a decision-support tool for patients and clinicians.
Competing interests C Ormerod: None declared, D Shackcloth: Grant/Research Support from: Abbott Laboratories Ltd, M Harrison: None declared, E Brown: None declared, K Bodger: Grant/Research Support from: Abbott Laboratories Ltd.