Reliability and predictors of resistive load detection in children with persistent asthma: a multivariate approach

Abstract

Objective: Resistive load detection tasks enable analysis of individual differences in psychophysical outcomes. The purpose of this study was to determine both the reliability and predictors of resistive load detection in children with persistent asthma who completed multiple testing sessions. Methods: Both University of North Carolina (UNC) Charlotte and Ohio University institutional review boards approved the research protocol. The detection of inspiratory resistive loads was evaluated in 75 children with asthma between 8 and 15 years of age. Each child participated in four experimental sessions that occurred approximately once every 2 weeks. Multivariate analyses were used to delineate predictors of task performance. Results: Reliability of resistive load detection was determined for each child, and predictors of load detection outcomes were investigated in two groups of children: those who performed reliably in all four sessions (n = 31) and those who performed reliably in three or fewer sessions (n = 44). Three factors (development, symptoms, and compliance) accounted for 66.3% of the variance among variables that predicted 38.7% of the variance in load detection outcomes (Multiple R = 0.62, p = 0.004) and correctly classified performance as reliable or less reliable in 80.6% of the children, χ²(12) = 28.88, p = 0.004. Conclusions: Cognitive and physical development, appraisal of symptom experiences, and adherence-related behaviors (1) account for a significant proportion of the interrelationships among variables that affect perception of airflow obstruction in children with asthma and (2) differentiate between children who perform more or less reliably in a resistive load detection task.

• Asthma
• children
• discriminant analysis
• factor analysis
• resistive loads
• threshold resistance to breathing

Acknowledgements

We thank Prof. Omer Van den Bergh and the Research Group on Health Psychology, KU Leuven, Leuven, Belgium, for the support provided to Dr. Harver during the preparation of the article; and Dr. Thomas Janssens for the review of earlier versions of the article.

Declaration of interest

We declare that all authors are free of any possible conflicts of interest in the manuscript, including financial, consultant, institutional or other relationships that might lead to bias or a conflict of interest. Drs. Harver and Kotses were involved in the conception and design of the study, and drafted initial versions of the manuscript. Dr. Harver has full access to the data and will vouch for the integrity of the data analysis. Dr. Humphries coordinated patient recruitment activities, contributed to the interpretation of results, and provided substantial comments on the manuscript. Ms. Dyer and Ms. Ersek participated fully in participant recruitment, data acquisition, and data analysis activities, helped construct the tables and figures, and reviewed the final version of the manuscript. The project described was supported by Grant Number R01HL068706 from the National Heart, Lung, and Blood Institute (PI: Dr. Harver; Co-PI: Dr. Kotses). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Heart, Lung, and Blood Institute or the National Institutes of Health.