Skip to main content

Table 5 Multiple stepwise regression analysis of the association of reactance measured at 5Hz with the severity of OSA

From: Impact of obstructive sleep apnea on lung volumes and mechanical properties of the respiratory system in overweight and obese individuals

Model   Unstandardized Coefficients Standardized Coefficients t P 95 % Confidence Interval for B Correlation coefficients
B Beta Lower Bound Upper Bound Zero-order Partial Part
1 Constant 2.623   0.916 0.361 −3.028 8.274    
  X5 −173.294 −0.504 −7.784 <0.001 −217.288 −129.361 −0.504 −0.504 −0.504
2 Constant −40.982   −4.404 <0.001 −59.344 −22.619    
  X5 −144.800 −0.421 −6.659 <0.001 −187.714 −101.887 −0.504 −0.448 −0.406
  weight 0.584 0.310 4.896 <0.001 0.327 0.786 0.422 0.345 0.298
3 Constant 0.225   0.056 0.955 −7.775 8.225    
  X5 −85.332 −0.482 −4.539 <0.001 −122.847 −47.819 −0.482 −0.482 −0.482
4 Constant −25.415   −2.061 0.043 −50.035 0.796    
  X5 −74.946 −0.424 −3.966 <0.001 −112.688 −37.223 −0.482 −0.436 −0.410
  BMI 0.912 0.234 2.191 0.032 0.081 1.744 0.340 0.259 0.227
5 Constant −3.143   −1.046 0.299 −9.141 2.855    
  X5 −84.601 −0.589 −6.002 <0.001 −112.726 −56.476 −0.589 −0.589 −0.589
6 Constant −23.130   −2.059 0.015 −41.536 −4.726    
  X5 −76.504 −0.532 −5.415 <0.001 −104.704 −48.305 −0.589 −0.552 −0.515
  BMI 0.711 0.225 2.258 0.025 0.090 1.333 0.358 0.269 0.217
  1. Independent variables: Zrs5, Gz, sGz, Grs, sGrs, R5, X5, X10, X15; Dependent Variable: AHI or HI. Model 1, 2 derived from male subject data by performing stepwise regression analysis; model 3, 4 derived from female subject data; model 5, 6 derived from female subject data with HI as a dependent variable
  2. Abbreviations: BMI body mass index, X5 respiratory system reactance at 5Hz, AHI apnea + hypopnea index, HI hypopnea index, Zrs5 respiratory system impedance at 5Hz (oscillatory frequency), R5 respiratory system resistance at 5 oscillatory frequencies, Grs respiratory conductance, reciprocal of R0 (total respiratory resistance, namely the resistance origin at the point of zero frequency), sGrs the specific Grs (the ratio of Grs to actual value of FRC), Gz reciprocal of Zrs5, sGz the specific Gz (the ratio of Gz to actual value of FRC)