Disability as a More Objective Measure in Inflammatory Bowel Disease

As the treatment paradigm in inflammatory bowel disease (IBD) has shifted from controlling symptoms to fully controlling disease in order to prevent organ damage and disability, some have argued that disability is a better, more objective measure than quality of life in clinical trials and population studies of IBD.

A November 2017 review in Therapeutic Advances in Gastroenterology by Patrick B. Allen, MD, and colleagues investigated measuring disability in IBD, defined in 2001 by the World Health Organization (WHO) in its International Classification of Functioning, Disability and Health (ICF) as “any restriction or lack (resulting from impairment) of ability to perform an activity in the manner or within the range considered normal for a human being.”

IBD is known to affect physical, psychological, familial, and social dimensions of life; the psychological impact of IBD may also contribute to disability. While experience with rheumatoid arthritis (RA) and multiple sclerosis (MS) has shown that disability can be prevented by disease-modifying drugs, such evidence is currently lacking in IBD. The review points out that WHO’s validated disability index can be used to explore whether disability can also be prevented in IBD.

In 2007 the IBD Disability Index (IBD-DI) was developed in collaboration with WHO and was validated in a French population-based study. The IBD-DI demonstrated high internal consistency, interobserver reliability and construct validity, and moderate intraobserver reliability. The IBD-DI is used mainly in the clinical trial setting because it evaluates functional status. A shortened, self-administered adaptation of the validated IBD-DI known as the IBD Disk was more recently developed to permit immediate visual representation of patient-reported disability markers such as sleep, sexual function, abdominal pain, body image, and energy. The disk lacks validation, but has the potential to be a valuable outcome measure for use during routine clinical visits.

Dr. Allen and colleagues performed a literature search through June 2017 using keywords pertaining to IBD and searched abstracts from the annual meetings of the major gastroenterology groups. Many studies and questionnaires about IBD primarily focused on subjective measures of disease. Fatigue and pain were found to be commonly reported symptoms in patients with IBD. A large proportion of patients were found to require opioid analgesia, and patients with IBD were reported to experience frequent and concomitant anxiety and depression. Overall, disability was found to be high in both Crohn disease and ulcerative colitis and to contribute to disease burden in IBD.

The review concludes that disability is prevalent in IBD and is seen in patients with ulcerative colitis (UC) before and after surgery and in Crohn disease (CD). “The IBD-DI should become a major secondary endpoint in clinical trials,” the review authors state. “This index needs to be expanded to include worldwide comparisons of disability among IBD patients in a longitudinal fashion.”

Future clinical trials will move away from simply targeting response and remission to ensure deep remission, improvement in defined patient-reported outcomes, and ultimately preventing and improving disability in IBD, the review concludes. “The costs and safety of these new therapeutic strategies in IBD that are being developed to change the natural history of disease with earlier and effective treatments in order to reduce long-term disability in IBD patients, remain to be established.”