Abstract
Background: The manovacuometer is a simple and non-invasive test to measure respiratory muscle strength. Guidelines recommend the use of a digital manovacuometer due to its high accuracy. Aims: The purpose of this study was to assess the test-retest reliability and concurrent validity of the digital manovacuometer developed at Federal University of Minas Gerais (UFMG, Belo Horizonte, Brazil). Methods: 30 healthy subjects were assessed (20-30 years old, normal body mass index and pulmonary function) using the manovacuometer UFMG and MicroRPM® (Micro Medical, UK). The following variables were analysed: maximal inspiratory pressures (MIP), maximal expiratory pressures (MEP) and nasal inspiratory pressure (SNIP), respectively. Statistical analysis was performed by Intraclass Correlation Coefficient (ICC) and paired Student t test (reliability); Pearson correlation, paired Student t test and the Bland-Altman method (validity). A p<0.05 was considered significant. The study was approved by the Ethic Committee. Results: For reliability, ICC values showed a high magnitude (0.89 - MIP, 0.84 - MEP and 0.78 - SNIP; p<0.05) and no significant differences were found between all analysed variables of the digital manovacuometer UFMG within two days (p>0.05). For validity, the correlation between the two instruments was of high magnitude for all variables (0.82 to 0.85) and no significant difference were found between the values obtained for both instruments (p> 0.05); Bland-Altman analysis showed no systematic overestimation or underestimation of MIP, MEP and SNIP. Conclusions: Our results demonstrated that the manovacuometer UFMG is a reliable and valid instrument to assess of MIP, MEP and SNIP in healthy subjects.
- © 2014 ERS