Prediction of early vascular cement leakage following percutaneous vertebroplasty in spine metastases: the Peking University First Hospital Score (PUFHS)

Table 3 The PUFHS

Characteristics included in the PUFHS^a	Scores	Estimates^b
Intercept		− 2.67
Primary cancer types
Slow growth	1	0.26
Moderate growth	2
Rapid growth	3
Number of treated vertebrae levels
1	1	0.65
2	2
3	3
≥ 4	4
Vertebrae collapse
No collapse	1	−0.30
Less than 50%	2
More than 50%	3

Notes: The PUFHS was created as follows:
P(Y = 1) = e^{−2.67 + 0.26x1 + 0.65x2 − 0.30x3} / (1+ e^{−2.67 + 0.26x1 + 0.65x2 − 0.30x3}); x 1 indicates primary cancer types; x 2 indicates number of treated vertebrae levels; x 3 indicates vertebrae collapse
An example was given as follows: if a spine metastasis patient with rapid growth cancer (3 points) had more than 50% vertebrae collapse (3 points) and one treated vertebra level (1 point), the vascular cement leakage probability of the patient was P (Y = 1) = e^{−2.67 + 0.26 ∗ 3 + 0.65 ∗ 1 − 0.30 ∗ 3} / (1+ e^{−2.67 + 0.26 ∗ 3 + 0.65 ∗ 1 − 0.30 ∗ 3}) = 10.53%
Abbreviations: PUFHS Peking University First Hospital Score
^aindicates characteristics were included according to the Least Absolute Shrinkage and Selection Operator; ^bindicates estimates were calculated from logistic regression analysis

ISSN: 1471-2407