Prognostic factors for unfavourable outcomes of patients with spinal tuberculosis in a country with an intermediate tuberculosis burden

Abstract

Aims Spinal tuberculosis (TB) remains an important concern. Although spinal TB often has sequelae such as myelopathy after treatment, the predictive factors affecting such unfavourable outcomes are not yet established. We investigated the clinical manifestations and predictors of unfavourable treatment outcomes in patients with spinal TB. Patients and Methods We performed a multicentre retrospective cohort study of patients with spinal TB. Unfavourable outcome was defined according to previous studies. The prognostic factors for unfavourable outcomes as the primary outcome were determined using multivariable logistic regression analysis and a linear mixed model was used to compare time course of inflammatory markers during treatment. A total of 185 patients were included, of whom 59 patients had unfavourable outcomes. Results In multivariate regression analysis, the factors associated with unfavourable outcome were old age (odds ratio (OR) 2.51; 95% confidence interval (CI) 1.07 to 5.86; p = 0.034), acid-fast bacilli (AFB) smear positivity in specimens obtained through biopsy (OR 3.05; 95% CI 1.06 to 8.80; p = 0.039), and elevated erythrocyte sedimentation rate (ESR) at the end of treatment (OR 3.85; 95% CI 1.62 to 9.13; p = 0.002). Patients with unfavourable outcomes had a significant trend toward higher ESR during treatment compared with patients with favourable outcome (p = 0.009). Duration of anti-TB and surgical treatment did not affect prognosis. Conclusion Elevated ESR at the end of treatment could be used as a marker to identify spinal TB patients with a poor prognosis. Patients whose ESR is not normalized during treatment, as well as those with old age and AFB smear positivity, should be aware of unfavourable outcomes. Cite this article: Bone Joint J 2019;101-B:1542–1549