The stability of breathing pattern components over time in different body positions

Abstract

Background: Elements of breathing pattern (BP) have potential to monitor respiratory health, or be used as outcome measures. Little published research has examined the stability of BP over time or in different body positions. Aim: To estimate the test-retest reliability of components of BP in sitting and supine positions. Methods: 46 healthy individuals (11 M) age (mean 31, SD 6.9) were recruited. Participants attended on 2 separate days a week apart. BP data were collected using Respiratory Inductive Plethysmography. BP was recorded for 15 minutes in sitting and 15 minutes in supine. After a break this was repeated to total 4 recordings. Participants were invited to return a week later to repeat the procedure. Group mean differences of BP components (inspiratory time, expiratory time, breathing cycle, respiratory rate, % of ribcage and abdomen contributions (RC/VT%, AB/VT%) were analysed within sessions, between sessions and between days using one way repeated measures ANOVA. Relative reliability was determined using intraclass correlation coefficient (ICC). Within subjects standard deviation (WSSD) was used to determine absolute reliability. 95% level of agreement (LA) was calculated to determine agreement between measures. Result: ANOVA and ICC results showed BP components to have good relative reliability. WSSD values were low to moderate suggesting good levels of absolute reliability. The 95% LA was narrow indicating acceptable agreement. Higher test re-test reliability was found for all components in sitting than supine. Conclusion: The BP components examined demonstrated good test re-test reliability in both sitting and supine positions in this sample of healthy participants.