What Is Worse: A Comparison of Solitary Versus Multifocal Pyogenic Spondylodiscitis Using a Nationwide Analysis of Readmission Rates and Risk Factors

Background: Spondylodiscitis is a growing infectious condition with significant morbidity. The impact of multifocal involvement remains understudied. This study compared 90-day all-cause readmission rates between patients with solitary versus multifocal spondylodiscitis and identified the associated risk factors. Methods: A retrospective analysis of the 2020 Nationwide Readmissions Database was conducted. Adult patients with primary spondylodiscitis were identified using ICD-10 codes and categorized into solitary or multifocal involvement groups. Demographic, clinical, and surgical data were extracted. Descriptive statistics and multivariate logistic regression were performed. Results: Of 6132 patients, 585 (9.6%) had multifocal disease. Multifocal patients were slightly younger (58.9 vs. 60.3 years; p = 0.049); had longer hospital stays (14.7 vs. 11.4 days; p < 0.001), time to readmission (p < 0.001); and surgery was more common (p = 0.003). Ninety-day readmission rates were similar (35.6% vs. 34.9%; p = 0.766). Type 2 diabetes was the only comorbidity significantly associated with multifocal disease (p = 0.020) and independently predicted readmission (aOR 1.236). Surgery and longer length of stay were protective (aOR 0.743; 0.0990). Conclusions: Multifocal spondylodiscitis is relatively common but not an independent risk factor for readmission. Readmission rates of both cohorts were similar. Surgery and prolonged hospitalization may reduce readmission risk.