Multiple logistic regression analysis of outcome variables given use of BMP.
| Variable | OR (95 % CI) | P |
| BMP use | 0.2 (0.01–3.7) | 0.269 |
| Age 18–41 y (ref: age >41 y) | 0.6 (0.03–15.2) | 0.782 |
| Smoking history | 2.2 (0.3–18.1) | 0.461 |
| History of COPD | 7.8 (0.4–147.5) | 0.170 |
| Diabetes with end-organ damage | 112.6 (5.7–2225.8） | 0.002 |
| Bone marrow aspirate use | 1.1 (0.1–15.9） | 0.918 |
| Local autograft use | 0.3 (0.02–4.1） | 0.346 |
| Iliac crest bone graft use | 21.9 (0.7–694.5） | 0.080 |
| Cellular bone allograft use | 0.4 (0.02–7.3) | 0.534 |
| Expandable cage use | 2.6 (0.3–25.5) | 0.412 |
| ASA classification>3 (ref: ≤3) | 0.6 (0.001–391.0) | 0.874 |
Abbreviations: ASA, American Society of Anesthesiologists; BMP, recombinant human bone morphogenetic protein 2; COPD, chronic obstructive pulmonary disease; ref, reference.
Note: Values in boldface represent statistical significance at P < 0.05. Nagelkerke R 2 = 0.381. Hosmer Lemeshow test P = 0.731.