OBJECTIVE: The lymphocyte-to-C-reactive protein ratio (LCRP) and Systemic Immune-Infl ammation Index (SII) can successfully predict 28-day mortality rates with community-acquired pneumonia METHODS: This prospective study was conducted in 2018. Hospitalized patients underwent follow-up evaluations 28 days after admission. RESULTS: A total of 345 patients with CAP were enrolled in this study. All-cause mortality at the 28th day of follow-up was 13.6 %. There were statistically signifi cant results between the 2 groups (survivors and nonsurvivors), in terms of the LCRP, SII, PSI, and CURB-65 values. Moreover, the optimal LCRP cutoff for predicting 28-day mortality was determined to be 4, with 89 % sensitivity, 73 % specifi city. Based on the average SII>3551for predicting 28-day mortality, the sensitivity, specifi city was 63.8 %, 68.1 % respectively. When the value of the cutoff PSI was ≥130 points, the sensitivity, specifi city was 68 %, 65 %, respectively. Based on 3 points and above as the cutoff value of the CURB-65 score, the sensitivity, specifi city was 80 %, 68 %, respectively. ROC curve analysis revealed that the areas of LCRP, SII, PSI, and CURB-65 under the AUC in terms of 28day mortality were 0,820,0,737,681, and 0,773, respectively, CONCLUSIONS: LCRP and SII level are valuable for predicting the mortality rate among patients with CAP at ED admission
