Pre-lung transplant measures of reflux on impedance are superior to pH testing alone in predicting early allograft injury

Table 2 Comparison of Cox univariate analyses of pH parameters of acid reflux and corresponding impedance measures of total reflux

	Univariate hazard ratio for time to acute rejection (95%CI)	P value
pH parameter of acid reflux
Acid reflux exposure, upright	1.01 (0.93-1.09)	0.87
Acid reflux exposure, recumbent	1.06 (0.92-1.21)	0.42
Acid reflux exposure, overall	1.03 (0.93-1.15)	0.52
Elevated acid reflux exposure (> 4.2%)	1.06 (0.92-1.21)	0.93
Total acid reflux episodes	1.00 (0.97-1.03)	0.90
Acid clearance	1.00 (1.00-1.00)	0.13
Impedance parameter of total reflux
Total reflux exposure, upright	1.11 (0.98-1.25)	0.11
Total reflux exposure, recumbent	1.25 (1.04-1.50)	0.011
Total reflux exposure, overall	1.18 (1.01-1.36)	0.031
Elevated total reflux exposure (> 1.4%)	1.88 (0.65-5.42)	0.24
Total reflux episodes	1.01 (1.00-1.02)	0.20
Bolus clearance	1.09 (1.01-1.17)	0.021

¹Statistically significant results in impedance measures of total bolus reflux.