The Crohn’s Anal Fistula Quality of Life Scale: A Patient-Reported Outcome Measure

As Crohn disease perianal fistulas often do not respond to available treatments, researchers developed a patient-derived quality-of-life tool to evaluate the impact of the condition on patients.

The Crohn’s Anal Fistula Quality of Life (CAF-QoL) scale complements objective clinical evaluation of fistula by capturing its effect on patients and is ready for use as a patient-reported outcome measure (PROM) in research and clinical practice, according to the results of a study published in Gut.

Perianal fistulas from Crohn disease are challenging for patients and clinicians, and often do not respond to available treatments. Currently, there are no specific PROM tools to measure response to treatment of perianal fistulas. Therefore, researchers developed a new, validated PROM by drafting a questionnaire using unstructured qualitative patient interviews on the experience of living with Crohn perianal fistula, a nationwide multidisciplinary consensus exercise, a systematic review of outcomes assessing medical/surgical/combined treatment, and a patient and public involvement day.

Using used data from 211 patients, the researchers developed the 28-item CAF-QoL. The questionnaire was found to demonstrate good internal consistency, excellent stability, and good responsiveness and construct validity, with positive correlation with the United Kingdom Inflammatory Bowel Disease Questionnaire (UK-IBDQ) and the Hospital Anxiety and Depression Scale (HADS).

Limitations of this study include the absence of data collected on other manifestations of perianal Crohn disease, which often coexist with fistulas. Another potential limitation of this study was the lack of access to exact data, such as magnetic resonance imaging and other anatomic fistula data for participants recruited via charities.

The authors concluded, “This new PROM lends itself to utility in clinical trial design for Crohn’s perianal fistulas, enabling consistency in data sets collected in this condition.” They added, “It also has the potential utility of assessment of disease impact in a clinic setting, to guide stratification of patients according to severity of disease impact and tailor appropriate management.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Adegbola SO, Dibley L, Sahnan K, et al. Development and initial psychometric validation of a patient-reported outcome measure for Crohn’s perianal fistula: the Crohn’s Anal Fistula Quality of Life (CAF-QoL) scale. Gut. Published online December 3, 2020. doi:10.1136/gutjnl-2019-320553