Letter to the Editor: Comparative Analysis of 30-Day Readmission, Reoperation, and Morbidity between Posterior Cervical Decompression and Fusion Performed in Inpatient and Outpatient Settings

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Asian Spine J. 2023;17(3):610-611
Publication date (electronic) : 2023 June 21
doi : https://doi.org/10.31616/asj.2023.0129.r1
Department of Neurological Surgery, The University of Oklahoma Health Sciences Center, Oklahoma, OK, USA
Corresponding author: Zachary Adam Smith University of Oklahoma Health Sciences Center, 1000 N Lincoln Blvd, Suite 4000, Oklahoma City, Oklahoma, 73104, USA Tel: +1-405-271-4912, E-mail: zachary-a-smith@ouhsc.edu
Received 2023 April 18; Accepted 2023 May 8.

We read with interest the article prepared and presented by Song et al. [1] and published by Asian Spine Journal titled “Comparative analysis of 30-day readmission, reoperation, and morbidity between posterior cervical decompression and fusion performed in inpatient and outpatient settings.” This paper is an important note for the spine surgery communities performing posterior cervical decompression and fusion (PCDF), an operation being commonly used currently in different hospitalization settings. The authors used data extracted from the National Surgical Quality Improvement Program (NSQIP) database to investigate the question whether undesirable 30-day postoperative outcomes such as morbidities (infectious, etc.), readmission, and reoperation differed between inpatient and outpatient settings. Finally, they concluded based on multi-variate analyses, there is a similar rate of adverse outcomes in the two settings, and PCDF could be safely performed as an outpatient procedure.

While the question is of utmost importance and can have major impacts on spine surgery practice, there are many methodological concerns that should be made clear. First, the definition of outpatient setting is not fully described either in paper nor in NSQIP’s guide [2]. They have mentioned that they used NSQIP’s variables as-is, which is ambiguous. Second, the conclusion cannot be fully drawn by what has been performed as there are desirable outcomes (i.e., stability, cervicalgia, etc.) and overall cost-benefit measures which are not quantified. There are many baseline variables that differ substantially between two groups of study. It might be deferred as multi-variate logistic regression would capture the confounding effects of these factors, but the fact is that two groups have such difference, multiple regression analysis cannot account for the confounding factors. For such heterogeneous samples with large sample reserve available, doing propensity matching followed by stepwise regression model creation is more promising, as carried out on same or similar databases several times before [3-6]. In addition, there are some other variables that ideally are required to be in the models (yet NSQIP may not provide them) and should be considered in real world decision making. Variables like the experience of surgeon, insurance coverage, severity of disease, presence of deformity and performance of alignment surgery, and neurological involvement. Another inherent limitation of NSQIP is that not every institute in United States is a partner and there is a leaning toward larger and wealthier academic centers that might hardly be generalizable to whole population and every setting [7]. Also, analytical efforts in disease severity and number of levels subgroups may have more practical results for our daily practice.

This is an impressive piece of work with immersive impact. However, the impact of this article is limited due to the limitations mentioned above, and broad extrapolations of the data should be limited. The above comments may mildly alter estimates, but most likely the main findings will remain the same. Future works to assess early discharge and ambulation may also point out the aim of this study in a more practical way.


Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Author Contributions

All authors provided the same amount of effort for preparation of this commentary.


1. Song J, Katz AD, Perfetti D, et al. Comparative analysis of 30-day readmission, reoperation, and morbidity between posterior cervical decompression and fusion performed in inpatient and outpatient settings. Asian Spine J 2023;17:75–85.
2. American College of Surgeons. ACS NSQIP participant use data file [Internet]. Chicago (IL): American College of Surgeons; 2021. [cited 2023 Apr 17]. Available from: https://www.facs.org/quality-programs/data-and-registries/acs-nsqip/participant-use-data-file/.
3. Johansen TO, Vangen-Lonne V, Holmberg ST, et al. Surgery for degenerative cervical myelopathy in the elderly: a nationwide registry-based observational study with patient-reported outcomes. Acta Neurochir (Wien) 2022;164:2317–26.
4. Nunna RS, Khalid S, Chiu RG, et al. Anterior vs posterior approach in multilevel cervical spondylotic myelopathy: a nationwide propensity-matched analysis of complications, outcomes, and narcotic use. Int J Spine Surg 2022;16:88–94.
5. Badhiwala JH, Ellenbogen Y, Khan O, et al. Comparison of the inpatient complications and health care costs of anterior versus posterior cervical decompression and fusion in patients with multilevel degenerative cervical myelopathy: a retrospective propensity score-matched analysis. World Neurosurg 2020;134:e112–9.
6. Morishita S, Yoshii T, Okawa A, Fushimi K, Fujiwara T. Comparison of perioperative complications between anterior decompression with fusion and laminoplasty for cervical spondylotic myelopathy: propensity score-matching analysis using Japanese Diagnosis Procedure Combination Database. Clin Spine Surg 2020;33:E101–7.
7. Alluri RK, Leland H, Heckmann N. Surgical research using national databases. Ann Transl Med 2016;4:393.

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