| | Total | Dead | CFR | CFR | X deaths | Y deaths |
|---|
# | # | % | X/Y | % | % |
|---|
Scenario A |
X | 500 | 0 | 0.0 | | | |
Y | 1500 | 30 | 2.0 | 0.0 | | |
Both X & Y | 500 | 30 | 6.0 | | | |
Total | 2500 | 60 | 2.4 | | | |
All-X |
1000
|
30
| 3.0 | | 50% | |
All- Y |
2000
|
60
| 3.0 | 1.0 | | 100% |
Scenario B |
X | 500 | 6 | 1.2 | | | |
Y | 1500 | 30 | 2.0 | 0.6 | | |
Both X & Y | 500 | 30 | 6.0 | | | |
Total | 2500 | 66 | 2.6 | | | |
All- X |
1000
|
36
| 3.6 | | 55% | |
All- Y |
2000
|
60
| 3.0 | 1.2 | | 91% |
Scenario C |
X | 500 | 10 | 2.0 | | | |
Y | 1500 | 30 | 2.0 | 1.0 | | |
Both X & Y | 500 | 30 | 6.0 | | | |
Total | 2500 | 70 | 2.8 | | | |
All- X |
1000
|
40
| 4.0 | | 57% | |
All- Y |
2000
|
60
| 3.0 | 1.3 | | 86% |
- In Scenario A, X does not have any mortality by itself, but when the subjects with both criteria are included X and Y appear to have the same mortality rate. Using only criterion X would select those children with zero mortality and those with both X and Y criteria and miss all the deaths related to criterion Y
- In Scenario B, there is a lower mortality with criterion X, however when the subjects fulfilling both criteria are included the relative case fatality rates are reversed so it appears now that X is a superior diagnostic parameter than Y. Yet its use only identifies 55% of the deaths
- In Scenario C, both X and Y have the same mortality rates but when the subjects with both criteria are included Y appears to be a superior diagnostic criterion. Yet this only leads to identification of 57% of deaths
- The columns % deaths shows the percentage of all deaths that would occur in children with criterion X or criterion Y as the single diagnostic tool. Criterion Y identifies more deaths than criterion X, but when the children with both criteria are included criterion X appears to have a higher case fatality rate
