Assessment results cut off −1.5 SD
|
---|
Observer 1
|
---|
Observer 2
|
Delayed
|
Not Delayed
|
Total
|
A
|
B
|
7
|
True positive
|
False positive
| |
7
|
0
| |
C
|
D
|
94
|
False negative
|
True negative
| |
11
|
83
| |
Total
|
18
|
83
|
101
|
- Sensitivity = A / A + C 7/18=39%.
- Specificity = D / B + D 83/83=100%.
- Total Agreement = A + D / A + B + C + D (7+83)/101=89%.
- Positive Predictive Value = A / A + B 7/7=100%.
- Negative Predictive Value = D / C + D 83/94=88%.
- Over-referral = B / A + B + C + D 0/101=0%.
- Under-referral = C / A + B + C + D 11/101=11%.
- Likelihood ratio—positive = Sensitivity / (1 – specificity) incalculable.
- Likelihood ratio—negative = (1 – sensitivity) / specificity .61.