Psychometric evaluation of a new patient-completed questionnaire for evaluating anal incontinence symptoms and impact on quality of life: the ICIQ-B.

Background: A psychometrically robust patient-completed questionnaire for anal incontinence, which reflects issues of importance to both clinicians and patients, was lacking for assessment purposes.

Objective: This study aimed to determine the psychometric properties of a new questionnaire developed to address this need, the International Consultation on Incontinence Questionnaire-Bowels module.

Design: Qualitative studies were used to refine the developmental version of the questionnaire. Quantitative studies were conducted to evaluate its psychometric properties.

Settings: Patients were invited to complete the questionnaire via postal administration.

Patients: Two hundred sixty-one patients with known bowel symptoms participated in the study (244 females, 17 males; mean age, 59.7 years (range, 24-92)).

Main Outcome Measures: The aspects of validity were evaluated in comparison with available evidence, responses to existing instruments, and physiological findings. Reliability was assessed through repeat administration of the questionnaire and evaluation of internal consistency by the Cronbach α coefficient. Responsiveness following treatment was evaluated by the use of the Wilcoxon signed rank test. Exploratory factor analysis was used to derive the final version of the questionnaire with evidence from the above studies.

Results: The final questionnaire contains 17 questions arranged in 3 scored domains: bowel pattern, bowel control, and quality of life, with 4 unscored items included to evaluate important issues from a clinical or patient perspective. The questionnaire demonstrated acceptable validity, "good" to "very good" reliability, and reasonable response to changes in symptom and quality-of-life status following intervention.

Limitations: Response rates varied according to location.

Conclusions: The International Consultation on Incontinence Questionnaire Bowel module is a psychometrically robust, self-report instrument for the evaluation of anal incontinence and its impact on quality of life. It is suitable for use in individuals with anal incontinence of varying causes. It includes a scoring system for use in clinical practice and research.