Outcomes of Patients With Schizophrenia and Bipolar Disorder Undergoing Lumbar Fusion: A Retrospective National Database Study

<sec><title>Background</title> Studies of mental health comorbidities in spine surgery have primarily focused on the relationship between anxiety or depression and postoperative outcomes. The purpose of this study was to compare rates of preoperative comorbidities and 90-day to 2-year outcomes between patients who underwent posterior lumbar fusion (PLF) with or without a diagnosis of schizophrenia (SCZ) or bipolar disorder (BD). </sec><sec><title>Methods</title> A retrospective review of the PearlDiver Mariner-170 database from 2010 to 2023 was performed. All included patients underwent 1-level PLF and had ≥2 year follow-up. Patients were grouped by whether they had a diagnosis of SCZ or BD within 1 year prior to PLF. The no-SCZ/BD group was propensity score–matched 3:1 on age, gender, Charlson Comorbidity Index score, and obesity to the SCZ/BD group. Univariate and multivariate analyses were performed to compare demographics, comorbidities, and outcomes between groups. Statistical significance was assessed at <italic>P</italic> < 0.05. </sec><sec><title>Results</title> After matching, 5475 patients without SCZ/BD and 1825 patients with SCZ/BD were included. The SCZ/BD group had an increased comorbidity burden and higher rates of preoperative alcohol, tobacco, and opioid use. At 90 days postoperatively, the SCZ/BD group had a higher rate of any complication (19.8% vs 15.0%, <italic>P</italic> < 0.001), including increased rates of readmission, hematoma/hemorrhage, sepsis/systemic inflammatory response syndrome, pneumonia, respiratory failure, and urinary tract infection. There were no differences in rates of reoperations between groups at 1 year or 2 years postoperatively. The SCZ/BD group had a greater total cost at both 1 year and 2 years, as well as increased opioid use at 1 year. After controlling for demographic and comorbidity differences, the SCZ/BD group was 22% more likely to experience 90-day complications (OR: 1.22; <italic>P</italic> = 0.008). However, there were no associations between SCZ/BD and 1 year or 2 year reoperations. </sec><sec><title>Conclusion</title> This study highlights the extensive comorbidities that can accompany patients with SCZ/BD who are undergoing PLF. Our findings also highlight the increased risk of postoperative complications in patients with these conditions—especially in the 90-day initial window, as well as increased costs over the first 2 years following surgery. Future prospective studies are needed to evaluate alternative approaches to screening and treating patients with SCZ or BD to optimize outcomes for this at-risk patient population. </sec><sec><title>Clinical Relevance</title> These findings suggest that patients with SCZ/BD are at increased risk for early complications after PLF. As our understanding of risks associated with patients undergoing PLF with significant mental health diagnoses grows, we must do more to identify and optimize these patients preoperatively and aggressively follow up during early recovery to identify and treat any adverse effects that may arise from surgery. </sec><sec><title>Level of Evidence</title> 4. </sec>