Jain D, Durand W, Shaw JD, et al. - A retrospective case-control study was performed to ascertain the influence of obesity on risk factors for adverse outcomes after lumbar spine fusion (LSF). Researchers distinguished adult patients who had undergone LSF in the State Inpatient Database. Individuals were distinguished as obese or nonobese using ICD-9 codes. The study enrolled a sum of 262,153 patients: 31,062 obese and 231,091 nonobese. Compared with non-obese patients, many medical comorbidities have less impact in obese patients in predicting adverse outcomes despite increased rates of adverse outcomes in obese patients. The data reflect the effect of obesity as an independent risk factor and have important implications for preoperative optimization.