Table 1.
Studies comparing NLR to only PLR, LMR, and d-NLR among different measured variables.
| Study | Measured variable | Summary of findings |
|---|---|---|
| (49) | COVID-19 diagnosis | In intubated COVID-19 patients: higher NLR and PLR and lower LMR were observed compared with healthy individuals. |
| (65) | COVID-19 diagnosis | NLR, PLR, and MLR were all higher in COVID-19 patients [order of higher AUC: MLR (0.892) > PLR (0.748) > NLR (0.722)]. |
| (66) | COVID-19 diagnosis | Both NLR and PLR correlated (order of higher correlation: NLR > PLR). |
| (67) | COVID-19 diagnosis | Both NLR and PLR were higher is SARS-CoV-2 (+) patients [order of higher AUC: PLR (0.669) > NLR (0.615)]. |
| (30) | COVID-19 pneumonia | NLR correlated in the multivariate analysis, but d-NLR, LMR, and PLR did not. |
| (30) | Disease severity | NLR, d-NLR, and PLR correlated with disease severity (order of better prediction: NLR > d-NLR > PLR). LMR did not correlate. |
| (59) | Disease severity | In this meta-analysis, NLR correlated better than PLR (SMD: 2.80 vs. 1.82). |
| (72) | Disease severity | In patients with type 2 diabetes mellitus: both NLR and LMR correlated with disease severity (AUC: NLR = 0.730, p = 0.002; LMR = 0.322, p = 0.015). |
| (73) | Disease severity | NLR, d-NLR, and PLR correlated with disease severity [order of higher AUC: NLR (0.808) > d-NLR (0.803) > PLR (0.769)]. LMR did not correlate (AUC = 0.296). |
| (74) | Disease severity | NLR remained independently related in the logistic regression analysis. PLR only correlated in the univariate analysis. No correlation was observed for LMR. |
| (53) | Disease severity | NLR, PLR, and LMR could predict disease severity (order of higher AUC: NLR > LMR > PLR). |
| (65) | Progression to ARDS | NLR, PLR, and LMR predicted progression to ARDS. |
| (53) | ICU admission | Among patients with severe disease, NLR correlated with ICU admission, but LMR and PLR did not. |
| (75) | ICU admission | NLR, PLR, and LMR predicted ICU admission (order of better prediction: NLR > PLR > LMR). |
| (76) | Mechanical ventilation | NLR predicted the need for mechanical ventilation, but PLR did not. |
| (72) | Time to negative PCR | In patients with type 2 diabetes mellitus, NLR correlated (multivariate analysis), but LMR did not (univariate analysis). |
| (72) | Duration of hospital stay | In patients with type 2 diabetes mellitus, NLR independently correlated but LMR was not related in the univariate analysis. |
| (77) | In-hospital mortality | NLR and d-NLR correlated, but LMR and PLR did not. |
| (66) | Mortality | NLR correlated, but PLR did not. |
| (78) | All-cause mortality | NLR could predict this parameter, but PLR could not. |
| (72) | Hospital expenses | In patients with type 2 diabetes mellitus, NLR independently correlated but LMR did not correlate in the univariate analysis. |
NLR, neutrophil to lymphocyte ratio; PLR, platelet to lymphocyte ratio; LMR, lymphocyte to monocyte ratio; MLR, monocyte to lymphocyte ratio; d-NLR, derived-NLR; AUC, area under the curve; SMD, standardized mean difference; ARDS, acute respiratory distress syndrome; ICU, intensive care unit; PCR, polymerase chain reaction.