Maximal inspiratory and expiratory pressures: intra- and inter-rater reliability

Abstract

Introduction: Maximal static respiratory pressures, measured using a manometer, express the strength of respiratory muscles in cmH₂O. Objective: To assess the intra- and inter-rater reliability of MIP and MEP. Methods: A random sample was used (n=70). Two independent raters performed three intraday (internal consistency) and two interdays (stability) measurements. The instrument used to measure the MIP and MEP was a digital manometer MDV®300 (MDI/Brazil), with a pressure range of ± 300 cmH₂O. The intraclass correlation coefficient (ICC) and the standard error of measurement (SEM) were calculated, the significance was P ≤ 0.05 and the statistical package used was SPSS 20.0. Results: Internal consistency: intra-rater MIP ICC = 0.97 and SEM (SEM%) = 6.71(6) e MEP ICC = 0.95 and SEM(SEM%) = 10.92(8); inter-rater MIP ICC = 0.98 and SEM(SEM%) = 5.41(5) and MEP ICC = 0.96 and SEM(SEM%) = 8.82(7). Stability: intra-rater MIP ICC = 0.95 and SEM (SEM%) = 7.92(7) and MEP ICC = 0.93 and SEM(SEM%) = 12.34(9); inter-rater MIP ICC = 0.96 and SEM(SEM%) = 6.36(6) and MEP ICC = 0.93 and SEM(SEM%) = 11.75(9). All statistical analyses were (P = 0.0001). Conclusion: MIP and MEP have adequate intra-and inter-rater reliability for clinical practice.