Table 1:
Accuracy of formula to predict the appropriate needle length to use in the confirmation samplea
| Actual SCD | Correct | Incorrect |
|---|---|---|
| <3.5 inches | 28/31 (90%)b | 3/31 (10%)c |
| >3.5 inches | 7/7 (100%)c | 0 (0%) |
| Total | 35/38 (92%) | 3/38 (8%) |
a
Accuracy of formula needle-length prediction, 3.5 or 5 inches. In 7/45 patients, the actual SCD was 3.5 inches; our formula predicted a 5-inch needle in 3/7 (43%) patients and a 3.5-inch needle in 4/7 (57%) patients.
b
Predicted 3.5-inch needle.
c
Predicted 5-inch needle.