1. Is comparison of changes in cardiac output, assessed by different methods, better than only comparing cardiac output to the reference method? 
N.W.F. Linton, R.A.F. Linton 
British Journal of Anaesthesia 
Volume 89, Issue 2, Pages (August 2002)
DOI: /bja/aef530
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Bland–Altman analysis comparing calibrated PCCO (PCCOcal) with CO (simulated data, n=250). Least squares regression gave y=0.97x+0.22; r2=0.89; 95% confidence interval, 0.87–0.92); limits of agreement, 1.59 to –1.60 litres min−1; bias, –0.01 litres min−1. Data from two patients have been plotted using large open symbols. From this analysis, it is not possible to assess the ability of PCCO to follow changes in CO within individual patients.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Bland–Altman analysis comparing changes within patients (simulated data, n=250). PCCO change is calculated as PCCO/PCCOcal and CO change as refCO/refCOcal (where ‘cal’ refers to the values obtained at calibration). Least squares regression gave y=0.02x; r2=0.002; 95% confidence interval for r, –0.08 to 0.17; limits of agreement were –18.4 to 22.4%. This diagram demonstrates that changes in PCCO were not related to changes in refCO, using the same data as presented in Figure 1. The two patients plotted with open symbols are no longer separated by the differences in initial cardiac output.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
Linear regression analysis between changes in COpa, and changes in COart, PCCO, and CCO (Δ1=T2–T1). (a) ΔCOpa–ΔCOart (r2=0.64); (b) ΔCOpa–ΔPCCO (r2=0.64); (c) ΔCOpa–ΔCCO (r2=0.75). Bold line=regression line.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Linear regression analysis between changes in COpa, and changes in COart, PCCO, and CCO (Δ2=T3–T2). (a) ΔCOpa–ΔCOart (r2=0.76); (b) ΔCOpa–ΔPCCO (r2=0.74); (c) ΔCOpa–ΔCCO (r2=0.82). Bold line=regression line.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

6. Fig 5
Δ1 (T2–T1) Bland–Altman plots between (a) ΔCOart and ΔCOpa (–0.10 (sd 2.43) litres min−1), (b) ΔPCCO and ΔCOpa (0.04 (2.54) litres min−1) and (c) ΔCCO and ΔCOpa (–0.12 (2.11) litres min−1). Unbroken lines show the mean difference and dotted lines show the 2 sd limits of agreement.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions

7. Fig 6
Δ2 (T3–T2) Bland–Altman plots between (a) ΔCOart and ΔCOpa (–0.04 (1.87) litres min−1), (b) ΔPCCO and ΔCOpa (–0.01 (2.01) litres min−1) and (c) ΔCCO and ΔCOpa (0.02 (1.61) litres min−1). Unbroken lines show the mean difference and dotted lines show the 2 sd limits of agreement.
British Journal of Anaesthesia  , DOI: ( /bja/aef530)
Copyright © 2002 British Journal of Anaesthesia Terms and Conditions