Bowel Irrigation Questionnaire Development of a Patient-Reported Experience Measure to assess the user experience of Transanal Irrigation

Aims

To develop the Bowel Irrigation Questionnaire (BIQ), a patient-reported experience measure (PREM) designed to assess the user experience of transanal irrigation (TAI).

Methods

Statements were generated through literature review and qualitative interviews with healthcare professionals (HCPs) and product users. Statements were rated on a 6-point content validity index scale through an international three-round online Delphi survey by 20 expert panel members. Consensus attainment was defined based on percentage agreement, statements which did not meet consensus were discussed at a final international online consensus meeting. The content validity of the PREM was evaluated through cognitive interviews and the Questionnaire on Questionnaires (QQ-10). Reliability was assessed using a test-retest design, where users completed the BIQ on two occasions one week apart.

Results

215 statements were generated from 9 multi-disciplinary qualitative interviews and literature review. Statements were refined to reduce repetition and ensure clarity. 73 statements grouped into 11 domains were reviewed through the Delphi survey. Following the Delphi survey and clinical consensus meeting, the preliminary BIQ consisted of 15 items. Six cognitive interviews were conducted, resulting in a finalised BIQ of 16 items. 32 product users completed both the QQ-10 and test-retest study, the results of which demonstrated good content validity and temporal stability respectively.

Conclusions

The Bowel Irrigation Questionnaire is a novel PREM designed to assess the user experience of TAI in both clinical and research settings. The instrument demonstrates good validity, acceptability and temporal stability, supporting its use as a reliable measure of patient experience.

Strengths and Limitations

• The item generation process was thorough and well-grounded in both literature review and qualitative interview, ensuring strong content validity from the outset.

• Product users were actively involved at every stage of development, supporting its relevance and use in real-world settings.

• Using an online Delphi survey meant we benefited from the input of topic experts from a range of countries whilst maintaining anonymity to minimise the influence of dominant individuals.

• This study represents the initial stages of PREM development; a larger study is required to fully evaluate the psychometric properties of the instrument, including construct validity and internal consistency.

• No a priori content validity index thresholds or predefined criteria for removing sub domains were specified; instead, decisions were made iteratively based on quantitative rating and qualitative feedback to balance content validity and patient burden. This may have influenced the final composition of the instrument.