Development and construct validation of a parent-proxy quality of life instrument in children with bronchopulmonary dysplasia aged 4-8 years old.

PURPOSE: Children with bronchopulmonary dysplasia often develop complications that affect them well into adult life. Very little is known about how this affects their quality of life, since no sensitive instrument is available to measure health-related quality of life in this population. In this study, a Dutch parent-proxy instrument was developed for this purpose.

METHODS: A list of items was generated after literature search and interviews with both parents of patients and clinical experts. Clinically relevant items were selected with the clinical impact method and item analysis. Results of clinical tests to measure complications in children with bronchopulmonary dysplasia were correlated with these items to select the items that show construct validity. Cronbach's alpha was calculated to estimate internal consistency of the items in the final questionnaire.

RESULTS: In total, 92 children and their parents and 7 clinicians participated. Of 130 identified items, 47 showed clinical relevance. Spirometry, the Child Behavior Checklist, mean arterial pressure, and body mass index were used to determine construct validity of 33 items. These items were structured within five domains: pulmonary complaints, school functioning, growth and nutrition, exercise and locomotion, emotional functioning and health care concerns. The questionnaire showed excellent internal consistency with Cronbach's alpha of 0.919.

CONCLUSION: This study developed a disease-specific parent-proxy instrument to measure health-related quality of life in children with bronchopulmonary dysplasia aged 4-8 years old, the BPD-QoL. All included items show construct validity and internal consistency reliability. Future research should focus on further validation and analysis of responsiveness and reliability.