The Impact of American Society of Anesthesiologists Status on Cost of Care and Length of Stay Following Posterior Cervical Decompression and Fusion

Background: Increased posterior cervical decompression and fusion (PCDF) procedures over the past decade have raised the prospect of bundled payment plans. The American Society of Anesthesiologists (ASA) Physical Status Classification system may enable accurate estimation of health care costs, length of stay (LOS), and other postoperative outcomes in patients undergoing PCDF. Methods: Low (I and II) versus high (III and IV) ASA class was used to evaluate 971 patients who underwent PCDF between 2008 and 2016 at a single institution. Demographics were compared using univariate analysis. Cost of care, LOS, and postoperative complications were compared using multivariable logistic and linear regression, controlling for sex, age, length of surgery, and number of segments fused. Results: The high ASA class cohort was older (mean age 62 years vs. 55 years, P < 0.0001) and had higher Elixhauser comorbidity index scores (P < 0.0001). ASA class was independently associated with longer LOS (2.1 days, 95% confidence interval [CI] 1.3–2.9, P < 0.0001) and higher cost ($2936, 95% CI $1457–$4415, P < 0.0001). Patients with high ASA class were more likely to have a nonhome discharge (3.9, 95% CI 2.8–5.6, P < 0.0001), delayed extubation (3.2, 95% CI 1.4–7.3, P = 0.006), intensive care unit stay (2.4, 95% CI 1.5 3.7, P = 0.0001), in-hospital complications (1.5, 95% CI 1.0–2.2, P = 0.03), and 30-day (3.2, 95% CI 1.5–6.8, P = 0.003) and 90-day (3.2, 95% CI 1.8–5.7, P = 0.0001) readmission. Conclusions: High ASA class is strongly associated with increased costs, LOS, and adverse outcomes following PCDF and could be useful for preoperative prediction of these outcomes.