Crohn's Disease Measurement
The Crohn's Disease Activity Index (CDAI) is a validated measure of disease activity and response to treatment in clinical trials.1 A score is calculated from a variety of factors including:
- The number of bowel movements in a day
- The use of antidiarrheal agents
- Severity of abdominal pain
- State of well-being
- Presence of extraintestinal manifestations
- Severity of anemia
- Amount of weight loss
- Presence or absence of abdominal mass
A calculation based on these parameters generates a number between 0 and 600. The higher the score, the more severe the disease. A score less than 150 indicates remission or inactive disease, and a reduction in score between 70 and 100 points represents a response to treatment in clinical trials.2,3
The Harvey-Bradshaw Index (HBI) was developed to offer a simpler alternative to the CDAI. Rather than relying on a 7-day patient diary (as does the CDAI), the HBI requires only a single day's worth of entries. Furthermore, the HBI does not include all the clinical variables that appear on the CDAI.4
The IBD questionnaire (IBDQ) is a health-related quality of life (HRQL) measurement specific to inflammatory bowel disease, measuring 4 dimensional scores including bowel function (eg, loose stool, abdominal pain), systemic function (eg, fatigue, altered sleep pattern), social function (eg, work attendance, need to cancel social events), and emotional function (eg, anger, depression, irritability).5 Each item is scored on a 7-point scale, with a score of 1 indicating a severe problem and 7 being no problem. Therefore, total IBDQ scores can range from 32 (very poor HRQL) to 224 (very good HRQL).5:
The IBDQ was developed as an outcome to assess treatment efficacy in clinical trials.6 A short-form IBDQ (the SIBDQ) has 10 of the 32 questions of the IBDQ and can discriminate between inactive and active disease.6 The SIBDQ may be useful in clinical trials or in clinical practice to identify patients who are coping poorly and who may benefit from adjuvant counseling or more aggressive therapy.6
Quality of life (QoL) can be accurately assessed using the HRQL questionnaire. HRQL encompasses physical function, emotional and social well-being, ability to work productively, and freedom from disease symptoms.5
Patients with IBD have a much lower HRQL than other individuals.
An HRQL questionnaire can range from a question asking to rate pain on a 10-point scale, to a survey of 100 questions, and can be either generic or disease-specific.5 A nonspecific measure of QoL that can be used with patients with CD is the SF (Short Form)-36. A 36-item questionnaire, the SF-36 is useful for estimating disease burden and comparing disease-specific benchmarks with general population norms.7
References:
- Best W, Becktel JM, Singleton J, Kern F. Development of a Crohn's disease activity index: national cooperative Crohn's disease study. Gastroenterology. 1976;70:439-444.
- Hanauer SB, Feagan BG, Lichtenstein GR, et al; ACCENT I Study Group. Maintenance infliximab for Crohn's disease: the ACCENT I randomised trial. Lancet. 2002;359:1541-1549.
- Schreiber S, Rutgeerts P, Fedorak RN, et al; CDP870 Crohn's Disease Study Group. A randomized, placebo-controlled trial of certolizumab pegol (CDP870) treatment of Crohn's disease. Gastroenterology. 2005;129:807-818.
- Best WR. Predicting the Crohn's Disease Activity Index from the Harvey-Bradshaw Index. Inflamm Bowel Dis. 2006;12:304-310.
- Feagan BG. Pharmacoeconomics and inflammatory bowel disease. In: Targan SR, Shanahan F, Karp LC, eds. Inflammatory Bowel Disease: From Bench to Bedside. 2nd ed. New York, NY:Springer;2005;471-480.
- Irvine EJ. Measuring quality of life in inflammatory bowel disease. In: Targan SR, Shanahan F, Karp LC, eds. Inflammatory Bowel Disease: From Bench to Bedside. 2nd ed. New York, NY:Springer;2005;481-494.
- Ware JE Jr. SF-36® Health Survey Update. Available at: http://www.sf-36.org/tools/sf36.shtml. Accessed November 30, 2008.
