Variable | QCD | IQR | 95% limits of agreement |
Pc-PH (n=112) | |||
Body surface area | 0.07 | 0.14 | ±24% |
Age | 0.10 | 0.21 | ±32% |
mPAP | 0.18 | 0.39 | ±48% |
RC-time | 0.21 | 0.42 | ±62% |
iPAH (n=719) | |||
Body surface area | 0.09 | 0.18 | ±25% |
Age | 0.19 | 0.36 | ±60% |
mPAP | 0.16 | 0.33 | ±50% |
RC-time | 0.17 | 0.34 | ±55% |
The data dispersion was quantified using the quartile coefficient of dispersion (QCD), the interquartile ratio (IQR), and the acceptance range for 95% of the values. IQR=(Q3-Q1)/median. QCD=(Q3−Q1)/(Q3+Q1). Pc-PH: postcapillary pulmonary hypertension; iPAH: idiopathic pulmonary hypertension; mPAP: mean pulmonary artery pressure. RC-time: PVR×C product. The 95% limits of agreement (acceptance range for 95% of the values) correspond to median±%error. We considered a claim for the presence of a “near-constant” variable in the database to be at least reasonable if the 95% limits of agreement fall within the clinically acceptable range of up to ±30%, i.e., if 95% of the computed values were located within 30% of the median value, (acceptance range from 0.7×median to 1.3×median).