# Table 3 Sensitivity, Specificity, and Predictive Value Positive (PVP) and Predictive Value Negative (PVN) Rates, and Predictive Summary Index (PSI) for Different MMRI-R "Cut-Points" - Validation Data

MMRI-R Cut-Point Sensitivity Specificity PVP PVN PSI
0 100.00   23.15
6 99.75 1.81 23.43 96.01 0.19
11 98.55 10.42 24.89 95.99 0.21
16 94.69 25.09 27.57 94.01 0.22
21 85.91 45.60 32.23 91.48 0.24
26 70.64 67.47 39.54 88.41 0.28
31 51.44 83.24 48.03 85.06 0.33
36 34.38 92.23 57.14 82.35 0.39
41 20.65 96.82 66.13 80.20 0.46
46 11.28 98.89 75.30 78.73 0.56
51 5.60 99.67 83.73 77.81 0.62
56 2.58 99.91 89.93 77.30 0.67
61 1.01 99.97 90.99 77.03 0.68
66 0.31 99.99 93.94 76.91 0.71
71 0.05 100.00 100.00 76.86 0.77
1. Table notes:
2. • Sensitivity is the probability of observing an MMRI-R score greater than or equal to the cut-point given mortality within six months.
3. • Specificity is the probability of observing an MMRI-R score less than the cut-point given survival beyond six months.
4. • Predictive value positive (PVP) and is the probability of dying within six months given an MMRI-R score is greater than or equal to the cut point.
5. • Predictive value negative (PVN) and is the probability of surviving beyond six months given an MMRI-R score less than the cut-point.
6. • The appropriateness of PVP and PVN depends on having a good estimate of population prevalence, in this case the prevalence of six month mortality.
7. • For ease of interpretation all probabilities were converted to percentages.
8. • Predictive Summary Index (PSI), calculated as PVP + PVN -100, is a overall measure of the gain in certainty associated with using the MMRI-R to make decisions. The practical range of PSI values is 0 to 1 with 0 reflecting a useless test and PSI = 1 for a test yielding perfect predictions.