Table 2.

Results of primary and secondary analyses for in vivo measurement agreement of IVP and ACM-IGP methods in 97 paediatric patients

	Paired measurements per patient [median (range)]	IAP [median (range)]			Spearman correlation coefficient (r2)	WSACS method validation criteria					MAPE (SD) (%)
		ACM-IGP (mmHg)		IVP (mmHg)		No. of patients/measure pairs	Bias (mmHg)	Precision (mmHg)	LOA (mmHg)	PE (%)
Target valuesa	–	–		–	≥ 0.6b	> 20 subjects	≤ │1│	≤ 2	− 4 to + 4	≤ 25	c
Primary analysis	1	6.8 (1.8–20.3)		6.0 (2.0–19.0)	0.95	97/97	0.3	0.8	− 1.3 to + 1.9	23	10 (11)
Secondary analysis	21 (1–132)	6.8 (0.9–23.0)	6.0 (1.0–20.0)		0.82	97/2770	0.3	1.2	− 2.1 to + 2.7	34	14 (16)

ACM-IGP air-capsule-based measurement of intra-gastric pressure, Ch. Charriére, IAP intra-abdominal pressure, IVP intra-vesical pressure, LOA limits of agreement, MAPE mean absolute percentage error, No number, PE percentage error, SD standard deviation, WSACS Abdominal Compartment Society (formerly: World Society of abdominal compartment syndrome)

^aTarget value specifications according to WSACS method validation criteria (bias + precision + LOA + PE) for the interchangeability of two IAP measurement methods [1]

^bSpearman’s correlation coefficient (r²; target: r² ≥ 0.6)

^cMean absolute percentage error (%) [19] were calculated in addition to recommended WSACS criteria [1]