Table 1. Cohort characteristics.

	N = 1,592
Age, years (mean ± SD)	49.6 ± 16.0
Male, n (%)	914 (57%)
Currently smoke, n (%)	488 (32%)
Illicit drug use, n (%)	167 (12%)
Alcohol use, n (%)	668 (46%)
Diabetes, n (%)	179 (11%)
Previous cardiac incident, n (%), includes angina, myocardial infarction, cardiovascular vascular disease, congestive heart failure	200 (13%)
Degenerative, n (%)	992 (62%)
Trauma, n (%)	372 (23%)
Neoplasm, n (%)	117 (7%)
Other diagnosis, n (%)	111 (7%)
Revision surgery, n (%)	286 (18%)
Anterior surgical approach, n (%)	292 (18%)
Posterior surgical approach, n (%)	934 (59%)
Combined surgical approach, n (%)	366 (23%)