Development and measurement properties of the adolescent-reported CBBDQ_12-18

Introduction Previously, the parent-reported Childhood Bladder and Bowel Dysfunction Questionnaire (CBBDQ) for children aged 5-12 years was found valid, reliable and responsive. The purpose of this study was to adapt the CBBDQ to construct the adolescent-reported CBBDQ(12-18), translate it into English according to guidelines, and determine its measurement properties, as defined by the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN). Methods Delphi panels, surveys on feasibility and acceptability, English translation and cross-cultural adaptation, and a prospective cohort study were conducted. Participants were adolescents, 12-18 years with and without bladder or bowel dysfunctions, and healthcare professionals who were experts in the field. The Medical Ethics Committee of Maastricht University approved the study (MEC 2018-0321). Results A total of 107 adolescents and 15 professionals participated from February 2017 to August 2023. The CBBDQ(12-18) was feasible and acceptable, translated into English and cross-culturally adapted. Content validity, moderate construct and fair criterion validity and excellent test-retest reliability with acceptable internal consistencies were demonstrated. Responsiveness at 6 months could not be demonstrated. Discussion The CBBDQ(12-18) is a symptom questionnaire on bladder and bowel problems in adolescents 12-18 years. It was developed in close cooperation with adolescents (some of them bilingual) and experienced healthcare workers. The outcomes regarding the measurement properties of the CBBDQ(12-18 ) were lower than those for the CBBDQ, but remained satisfactory, except responsiveness. A possible limitation of the present cohort study may be its sample sizes, although the total sample sizes of this study were sufficient in line with COSMIN guidelines.