In gratitude of the loyal support of our members, the CNS is offering complimentary 2021 Annual Meeting registration to all members! Learn more.

  • Does Patient Selection Account for the Perceived Cost Savings in Outpatient Spine Surgery?

    Final Number:

    Benjamin Mundell PhD; Marcus J. Gates MD; Mohammed Ali Alvi MD; Panagiotis Kerezoudis; Brett Arthur Freedman; Ahmad Nassr MD; Samuel Hohmann Ph.D; Mohamad Bydon MD

    Study Design:

    Subject Category:

    Meeting: Section on Disorders of the Spine and Peripheral Nerves Spine Summit 2018

    Introduction: . The perceived cost savings with comparable or improved outcomes to inpatient admission for the same procedures is desirable in an era where health expenditures are scrutinized. In this study, the authors’ hypothesized that total savings in outpatient spine surgery is largely driven by patient selection and biases towards healthier patients.

    Methods: A meta-analysis assessed patient selection factors and outcomes associated with outpatient spine procedures. Additional Bayesian analysis, informed by the meta-analysis results, was performed on a national administrative database to further compare inpatient and outpatient direct costs.

    Results: Outpatient procedures were associated with younger patient age (MD = -2.33, 95% CI: -4.40 - -0.25) and no diabetes diagnosis (OR = 0.77, 95% CI: 0.51-0.97). Outpatient procedures were associated with a lower likelihood of reoperation (OR = 0.44, 95% CI: 0.18-0.87), 30-day readmission (OR = 0.39, 95% CI: 0.10-0.80), complication (OR = 0.29, 95% CI: 0.15-0.49), and lower overall costs (MD = -$13,834, 95% CI: -$22,883 - -$4629). Additional analysis of the national administrative data revealed more modest cost savings than those found in the meta-analysis for outpatient spine surgeries relative to inpatient spine surgeries. Estimated cost savings for both younger - $555 for those age 30-35 (95% CI: -$733 – -$374) - and older patients - -$7290 for those age 65-70 (95% CI: -$7380 –$7190) were less than the overall cost savings found in the meta-analysis

    Conclusions: Compared to inpatient surgery, outpatient spine surgery was associated with better short-term outcomes and an initial reduction in direct costs. A selection bias for outpatient procedures towards younger healthier patients may confound these results. The additional analysis of the national database suggests that cost savings in the outpatient setting may be less than previously reported and a result of outpatient procedures being offered more frequently to younger and healthier individuals.

    Patient Care: Our research will help spine surgeons identify the ideal patient for outpatient spine surgery. it will also help the surgeons evaluate the current evidence related to comparison of outcomes between outpatient and inpatient spine surgery.

    Learning Objectives: By the conclusion of this session, participants should be able to: 1) Appreciate the current utilization trends of outpatient spine surgery. 2) Discuss the potential selection bias for younger healthier patients in outpatient spinal surgery. 3) Discuss the validity of favorable outcomes that are attributed to outpatient spine surgery in the context of facts presented above.


We use cookies to improve the performance of our site, to analyze the traffic to our site, and to personalize your experience of the site. You can control cookies through your browser settings. Please find more information on the cookies used on our site. Privacy Policy