Association between neutrophil percentage-to-albumin ratio and pneumonia in patients with traumatic spinal cord injury

Study design Retrospective cohort study. Objectives To investigate the association between neutrophil percentage-to-albumin ratio (NPAR) and pneumonia in patients with SCI. Setting Department of Rehabilitation Medicine Center, West China Hospital, Sichuan University. Methods SCI patients admitted to West China Hospital within 24 h of injury were consecutively enrolled. Blood samples were collected on admission. Pneumonia was diagnosed based on chest radiography and clinician records of patient symptoms and laboratory tests. Multivariable logistic regression analysis was performed to determine the relationship between NPAR and pneumonia. Receiver operating characteristic (ROC) curves were generated to assess the predictive value of NPAR. Results A total of 264 SCI patients were included, of whom 65 (24.6%) developed pneumonia. NPAR was positively correlated with pneumonia (OR 2.66, 95% CI, 1.06–6.71, p = 0.038). Patients in the upper NPAR tertile (2.35–3.71) had a higher risk of pneumonia than patients in the lower tertile (1.66–2.12) after adjustment for potential confounders (OR 2.55, 95% CI, 1.05–6.19, p = 0.039). The risk of pneumonia increased stepwise across NPAR tertiles ( p for trend = 0.031). The optimal cutoff value of NPAR for predicting pneumonia was 2.17 with a sensitivity of 0.82 and a specificity of 0.50. There was a significant interaction between NPAR and neurological level of injury ( p for interaction = 0.034), with no significant association between NPAR and pneumonia in patients with cervical SCI. Conclusions A higher NPAR was independently associated with higher risk of pneumonia in a dose-dependent manner in patients with non-cervical SCI.