1370 is the Liverpool Respiratory Symptom Questionnaire (LRSQ) an Acceptable Tool to Use in Longitudinal Cohort Studies?

Background The Liverpool Respiratory Symptom Questionnaire (LRSQ) is a validated tool for evaluating the prevalence of common paediatric respiratory symptoms amongst preschool children. The questionnaire also evaluates the quality of life for children, and their parents. The LRSQ was designed as an outcome measure for epidemiological and trial purposes, and can also be used to differentiate between children with and without active respiratory disease. To date, the LRSQ has not been validated for use in longitudinal cohort studies. The Liverpool Respiratory Birth Cohort Study (LRBCS) has used the LRSQ longitudinally, in order to identify the main determinants of poor respiratory health in preschool children over time. The content validity of the LRSQ was approved by respiratory paediatricians, as part of the questionnaire’s original validation. Now, data from the LRBCS (about the questionnaire’s internal consistency) may be able to support the use of the LRSQ in future longitudinal cohort studies. Objectives To validate the LRSQ as a tool, which is suitable for use in longitudinal studies of preschool children. Methods 689 infants were enrolled onto the LRBCS between 2013 and 2014. From 4-months-old to 58-months-old, the infants’ parents completed the LRSQ via an online platform. This provided data about each child’s respiratory health, in eight separate domains, at up to ten six-monthly ‘timepoints’. The internal consistency of each of the questionnaire’s eight domains was measured with Cronbach’s alpha analysis – using all relevant responses from the entire dataset. Results Of the LRSQ’s eight domains, four showed excellent internal consistency – as indicated by an alpha score of ≥0.9. The other four domains displayed good internal consistency – as indicated by an alpha score of ≥0.8. By excluding one outlying survey ‘timepoint’, six domains have excellent internal consistency and two have good internal consistency. Conclusions Based upon data from ten ‘timepoints’ over the first five years of childhood, the LRSQ displays a good to excellent level of internal consistency. This property proves that the LRSQ can detect changes in respiratory symptoms over time, in this particular cohort of preschool children. Further external validation is required, using independent cohorts of preschool children.