Predicted and observed probabilities of bone marrow involvement according to the Zs score
. | . | Derivation group . | . | Validation group . | . | Total patients . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Risk group (predicted probability of BMI*) . | Zs . | N . | % . | N . | % . | N . | % . | |||
| Low (< 0.75%) | < 0 | 1/403 | 0.2 | 1/243 | 0.4 | 2/646 | 0.3 | |||
| Standard (0.75%-10%) | 0-9 | 7/265 | 2.6 | 16/279 | 5.7 | 23/544 | 4.2 | |||
| High (> 10%) | ≥ 10 | 38/158 | 24.1 | 36/132 | 27.3 | 74/290 | 25.5 | |||
. | . | Derivation group . | . | Validation group . | . | Total patients . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Risk group (predicted probability of BMI*) . | Zs . | N . | % . | N . | % . | N . | % . | |||
| Low (< 0.75%) | < 0 | 1/403 | 0.2 | 1/243 | 0.4 | 2/646 | 0.3 | |||
| Standard (0.75%-10%) | 0-9 | 7/265 | 2.6 | 16/279 | 5.7 | 23/544 | 4.2 | |||
| High (> 10%) | ≥ 10 | 38/158 | 24.1 | 36/132 | 27.3 | 74/290 | 25.5 | |||
BMI indicates bone marrow involvement.
The predicted probability of BMI was calculated from equation 1, using the data of Table 1 (column 2).