Table 3.
Reliability and accuracy for the predictive equations
| ICC | ME, mmol/dl | MAPE, s% | MAE, mmol/dl | RMSE, mmol/dl | |
|---|---|---|---|---|---|
| All patients | |||||
| Equation 1 | 0.539 (0.373 to 0.663) | −0.04 (−0.05 to −0.02) | 7.35 (6.17 to 8.53) | 0.08 (0.07 to 0.09) | 0.04 (0.03 to 0.06) |
| Equation 2 | 0.609 (0.480 to 0.709) | −0.03 (−0.04 to −0.01) | 6.51 (5.43 to 7.59) | 0.07 (0.06 to 0.08) | 0.03 (0.02 to 0.05) |
| Equation 3 | 0.521 (0.347 to 0.651) | −0.04 (−0.06 to −0.02) | 7.30 (6.10 to 8.50) | 0.08 (0.07 to 0.09) | 0.04 (0.03 to 0.06) |
| Published general predictive equations | |||||
| McLean-Hastings | 0.345 (−0.095 to 0.675) | −0.24 (−0.26 to −0.22) | 21.72 (19.95 to 23.48) | 0.24 (0.22 to 0.26) | 0.30 (0.25 to 0.34) |
| Zeisler | 0.496 (−0.070 to 0.766) | 0.11 (0.10 to 0.13) | 10.64 (9.61 to 11.68) | 0.12 (0.11 to 0.13) | 0.08 (0.07 to 0.10) |
| Zeisler simplified | 0.506 (−0.051 to 0.766) | 0.11 (0.09 to 0.12) | 10.37 (9.33 to 11.41) | 0.12 (0.11 to 0.13) | 0.08 (0.07 to 0.10) |
| Hanna | 0.264 (0.050 to 0.621) | −0.26 (−0.27 to −0.25) | 23.65 (22.15 to 25.16) | 0.26 (0.25 to 0.27) | 0.30 (0.27 to 0.33) |
| Pottgen | 0.508 (0.174 to 0.699) | −0.08 (−0.10 to −0.06) | 9.67 (8.29 to 11.04) | 0.11 (0.09 to 0.12) | 0.08 (0.05 to 0.10) |
| Siggaard-Andersen | 0.731 (0.646 to 0.799) | −0.01 (−0.03 to 0.01) | 8.04 (7.04 to 9.04) | 0.09 (0.08 to 0.10) | 0.05 (0.04 to 0.06) |
| Butler | 0.095 (−0.063 to 0.251) | 0.02 (0 to 0.04) | 8.48 (6.89 to 10.07) | 0.09 (0.08 to 0.11) | 0.06 (0.04 to 0.09) |
| Special populations | |||||
| Critically ill patientsa | |||||
| Equation 1 | 0.556 (0.054 to 0.844) | −0.04 (−0.08 to 0) | 6.20 (3.91 to 8.50) | 0.07 (0.04 to 0.09) | 0.02 (0.01 to 0.04) |
| Equation 2 | 0.640 (0.16 to 0.879) | −0.03 (−0.07 to 0) | 5.21 (2.79 to 7.63) | 0.06 (0.03 to 0.08) | 0.02 (0 to 0.04) |
| Equation 3 | 0.528 (−0.015 to 0.835) | −0.05 (−0.09 to −0.01) | 6.44 (3.83 to 9.05) | 0.07 (0.04 to 0.09) | 0.03 (0.01 to 0.04) |
| Forster | 0.623 (0.113 to 0.874) | −0.02 (−0.07 to 0.03) | 8.73 (4.74 to 12.72) | 0.07 (0.04 to 0.10) | 0.03 (0.01 to 0.05) |
| Patients ≥80 years oldb | |||||
| Equation 1 | 0.417 (0.008 to 0.699) | −0.06 (−0.08 to −0.03) | 7.36 (5.43 to 9.30) | 0.08 (0.06 to 0.10) | 0.03 (0.02 to 0.05) |
| Equation 2 | 0.494 (0.108 to 0.743) | −0.04 (−0.07 to −0.02) | 6.48 (4.75 to 8.21) | 0.07 (0.05 to 0.08) | 0.03 (0.01 to 0.04) |
| Equation 3 | 0.390 (−0.054 to 0.695) | −0.07 (−0.09 to −0.04) | 7.81 (5.82 to 9.80) | 0.08 (0.06 to 0.10) | 0.04 (0.02 to 0.05) |
| Pfitzenmeyer | 0.441 (−0.095 to 0.759) | −0.08 (−0.10 to −0.06) | 5.94 (4.47 to 7.40) | 0.09 (0.07 to 0.11) | 0.04 (0.03 to 0.05) |
ICC = Intraclass concordance coefficient, values of s+1 denote perfect concordance and 0 denotes absence of concordance; ME = mean error; MAPE = mean absolute percentage error; MAE = mean absolute error; RMSE = root mean square error, in all cases lower is better. 95s% CIs are given in parentheses.
a
For 12 (8.2s%) critically ill patients.
b
For 26 (17.8s%) patients ≥80 years old.