Crohn’s Disease Activity Index (CDAI)
Why Use
Crohn’s disease is a complex and multifactorial entity. Assessment of disease activity and quality of life are difficult to quantify — a standardized, accurate tool helps compare severity across patients, as well as track individual patients over time.
When to Use
Adults with active Crohn’s disease.
Formula
Pearls / Pitfalls
The Crohn's Disease Activity Index (CDAI) allows quantitation and tracking of disease activity in adults with Crohn’s disease. The CDAI may have wide variation in definitions and scoring in real world use. Lab variations of “normal” hematocrit in men and women can often lead to markedly different CDAI scores; similarly, changes in weight can lead to score differences as well.
Management
Multiple algorithms use the score, though we are not aware of any that are validated based on outcomes. Refer to ACG guidelines for management of acute diarrheal infections in adults.
Critical Actions
Requires laboratory values, detailed history-taking and a 7-day patient diary of symptoms.
Advice
The CDAI is the de facto gold standard and is used in studies worldwide.
More Information
Criteria Amount Answer Multiplier Number of liquid stools Sum, past 7 days ×2 Abdominal pain Average daily rating × 7 0 = None 1 = Mild 2 = Moderate 3 = Severe ×5 General well-being Average daily rating × 7 0 = Generally well 1 = Slightly under par 2 = Poor 3 = Very poor 4 = Terrible ×7 Extra- intestinal/ physical complaints* Number of complications listed 0 = No, 1 = Yes* ×20 Antidiarrheal drugs Use in the previous 7 days 0 = No 1 = Yes ×30 Abdominal mass 0 = No 2 = Questionable, 5 = Definite ×10 Hematocrit Expected – observed hematocrit Men: 47% observed, Women: 42% observed ×6 Body weight % below ideal weight (Ideal - observed) / ideal × 100 ×1 *Arthritis/arthralgia, mucocutaneous lesions (e.g. erythema nodosum, aphthous ulcers), iritis/uveitis, anal disease (fissure, fistula, etc), external fistula (enterocutaneous, vesicle, vaginal, etc), fever over 37.8°C Score interpretation: CDAI <150 is a marker of remission of Crohn’s disease. CDAI >450 is a marker of severe Crohn's disease.