Preparing for Bundled Payments in Cervical Spine Surgery Do We Understand the Influence of Patient, Hospital, and Procedural Factors on the Cost and Length of Stay?

Study Design. Retrospective, observational study. Objective. To examine the influence of patient, hospital, and procedural characteristics on hospital costs and length hospital of stay (LOS). Summary of Background Data. Successful bundled payment agreements require management of financial risk. Participating institutions must understand potential cost input before entering into these episodes-of-care payment contracts. Elective anterior cervical discectomy and fusion (ACDF) has become a popular target for early bundles given its frequency and predictability. Methods. A national discharge database was queried to identify adult patients undergoing elective ACDF. Using generalized linear models, the impact of each patient, hospital, and procedures characteristic on hospitalization costs and the LOS was estimated. Results. In 2011, 134,088 patients underwent ACDF in the United States. Of these 31.6% had no comorbidities, whereas 18.7% had three or more. The most common conditions included hypertension (44.4%), renal disease (15.9%), and depression (14.7%). Mean hospital costs after ACDF was $ 18,622 and mean hospital LOS was 1.7 days. With incremental comorbidities, both hospital costs and LOS increased. Both marginal costs and LOS rose with inpatient death (+$ 17,181, +2.0 days), patients with recent weight loss (+$ 8351, +1.24 days), metastatic cancer (+$ 6129 +0.80 days), electrolyte disturbances (+$ 4175 +0.8 days), pulmonary-circulatory disorders (+$ 4065, +0.6 days), and coagulopathies (+$ 3467, +0.58 days). Costs and LOS were highest with the following procedures: addition of a posterior fusion/instrumentation ($ +11,189, +0.9 days), revision anterior surgery (+$ 3465, +0.3 days), and fusion of more than three levels (+$ 3251, +0.2 days). Patients treated in the West had the highest costs (+$ 9300, +0.3 days). All P values were less than 0.05. Conclusion. Hospital costs and LOS after ACDF rise with increasing patient comorbidities. Stakeholders entering into bundled payments should be aware of that certain patient, hospital, and procedure characteristics will consume greater resources.