Comparison of Cost and Perioperative Outcome Profiles for Primary and Revision Posterior Cervical Fusion Procedures

Michael L. Martini, PhD; Rebecca B. Baron, BS; Jonathan S. Gal, MD; Sean N. Neifert, BS; William H. Shuman, BA; Alexander J. Schupper, MD; Emily K. Chapman, BS; Ian T. McNeill, MD; Jeremy Steinberger, MD; John M. Caridi, MD

Disclosures

Spine. 2021;46(19):1295-1301. 

In This Article

Results

One thousand one hundred twenty four patients were included in this study, including 906 patients who did not have a prior surgery and 218 patients who were undergoing a revision procedure (Table 1). The revision procedure cohort tended to be younger (53.0 vs. 60.5 yrs) and had a smaller proportion of male patients (54.1% vs. 62.0%) compared with the non-revision cohort. Interestingly, despite having a lower mean age, the revision cohort also had a significantly greater proportion of patients with high Elixhauser Index comorbidity burden scores. In addition, revision cases tended to involve fewer spinal segments (3.6 vs. 4.1 segments) and shorter surgical durations (179.3 vs. 206.3 min). There was not a significant difference in the mean intraoperative estimated blood loss between the surgical cohorts (450.3 vs. 289.9 mL).

There were no differences in the overall rates of complications (21.6% vs. 17.8%; P = 0.20) or in any of the specific medical or surgery-related complications that were examined, including airway complications, hemorrhage, cerebrovascular accident, deep vein thrombosis, pneumonia, surgical site infection, urinary tract infection, durotomy, or death (Table 2). However, our analysis also revealed that the primary surgery cohort experienced required ICU stays (18.4% vs. 8.7%; P = 0.0005) and non-home discharges (32.4% vs. 19.8%; P = 0.0003) at significantly higher rates than the revision surgery cohort. Conversely, the revision surgery cohort was found to have a significantly higher rate of ED visits within 30 days of hospital discharge (5.1% vs. 2.4%; P = 0.04) compared with the primary surgery cohort (Table 2). No statistical differences were noted in the rates of prolonged hospitalizations, unplanned hospital readmissions, or returns to the operating room between the two surgical cohorts.

Adjusted analyses showed that the odds of any complication occurring did not differ significantly between the patient cohorts (odds ratio [OR] 1.35; 95% confidence interval [CI] 0.89–2.04; P = 0.16) (Table 3). Similarly, the revision cohort did not face increased odds of other adverse outcomes including delayed extubation (OR 0.65; 95% CI 0.27–1.56; P = 0.33), non-home discharge (OR 0.71; 95% CI 0.46–1.09; P = 0.12), return to the operating room (OR 1.45; 95% CI 0.15–13.83; P = 0.74), or 30-day unplanned hospital readmission (OR 0.54; 95% CI 0.23–1.26; P = 0.15). While the revision cohort did experience significantly increased odds of an ED admission within 30 days of hospital discharge (OR 2.30; 95% CI 1.03–5.15; P = 0.04), they also faced a significantly reduced risk of a required ICU stay during their hospitalization courses (OR 0.37; 95% CI 0.20–0.70; P = 0.002).

An in-depth, multivariate cost analysis was performed to compare the various cost sources between patients undergoing primary versus revision PCDF procedures (Table 3). Despite sharing similar mean lengths of stay (P = 0.52) and days spent in the ICU (if an ICU stay was required; P = 0.94), the revision surgery cohort experienced significantly increased direct costs of hospitalization (estimate: +$1999; 95% CI $142–$3858; P = 0.03) and surgical costs (estimate: +$2113; 95% CI $1121–$3106; P < 0.0001). Other cost categories, including laboratory, pharmacy, and nursing costs, were similar between the cohorts.

Finally, predictors of complication risk, required ICU stay, and direct hospitalization costs were explored using multivariate modeling across the study population (Table 4). Only the Elixhauser comorbidity burden was a significant predictor of complication risk in both surgical cohorts (OR 1.1; 95% CI 1.07–1.13; P < 0.0001). Statistically significant predictors of a required ICU stay during the hospitalization course included age (OR 1.02; 95% CI 1.01–1.04; P = 0.005), Elixhauser comorbidity burden (OR 1.08; 95% CI 1.05–1.11; P < 0.0001), surgical duration (OR 1.009; 95% CI 1.007–1.011; P < 0.0001), and prior surgery (OR 0.37; 95% CI 0.20–0.70; P = 0.002). Several demographic and perioperative variables were also found to be predictors of direct costs, including prior surgery (P = 0.03), male sex (P = 0.02), Elixhauser comorbidity burden (P < 0.0001), number of segments operated (P < 0.0001), preoperative diagnosis of radiculopathy (P = 0.01), surgical duration (P < 0.0001), and total EBL (P < 0.0001).

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