Table 2 Bland-Altman Analysis for the two methods: IAP & IBP for all measures (IAP = 0–22 mmHg) Versus measures for High IAP (IAP > 12 mmHg)

First measurement [Method A]

Intra Abdominal Pressure (IAP = 0–22 mmHg)

Intra Abdominal Pressure (IAP > 12 mmHg)

Second measurement [Method B]

Intra Bladder Pressure (IBP with IAP = 0–22 mmHg)

Intra Bladder Pressure (IBP with IAP > 12 mmHg)

 Sample size

388

81

 Arithmetic mean (Bias)

−0.097

−0.282

 95% CI

−0.236 to 0.042

−0.619 to 0.056

 Standard Error (SE)

0.070829

0.1697

 Standard deviation (Precision)

1.3952

1.5278

 Coefficient of variation (%)

11.8956

6.6932

 Lower limit

−2.8312

−3.2760

 95% CI

−3.0694 to −2.5930

−3.856 to − 2.696

 Upper limit

2.6379

2.7130

 95% CI

2.3997 to 2.8761

2.133 to 3.293