Objective Onodera's Prognostic Nutritional Index (PNI), determined as "10× albumin (g/dL) + 0.005× lymphocyte count (/μL)," was originally designed to determine the risk of complications following gastrointestinal surgery. This single-center, retrospective observational study was designed to investigate whether or not the PNI can predict the treatment outcome. Methods We consecutively reviewed HIV-negative pulmonary tuberculosis adults in an isolation ward. Most patients were being treated with standard three- or four-drug regimens. Patients were discharged after consecutive negative smears/cultures were confirmed. The risk of all-cause death was assessed using a multivariable Cox proportional hazard model and a log-rank trend test. Results During the observation period, we observed 371 consecutive patients with a median age of 72 (interquartile range [IQR]: 54-82) years. In our cohort, 295 (79.5%) patients were discharged alive, and 76 (20.5%) died in-hospital. Patients who died in-hospital had a lower PNI [median 21.2 (IQR: 18.5-25.9)] than those who were discharged alive [median 35.1 (IQR: 28.0-43.3); p<0.001]. The area under the receiver operating characteristic curve was 0.87. After dividing the patients based on the baseline PNI quartile, those patients with a lower PNI showed a poorer survival than those with a higher PNI (log-rank trend p<0.001). After adjusting for other baseline variables, the baseline PNI was still associated with in-hospital death with a hazard ratio of 0.86 (95% confidence interval: 0.82-0.91, p<0.001). Conclusion Our results showed that a low PNI was clearly related to a poor survival prognosis in smear-positive HIV-negative pulmonary tuberculosis inpatients.
Keywords: antibiotics; blood cell count; cohort study; nutrition; pulmonary tuberculosis.