Neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio, and platelet-lymphocyte ratio in stroke-associated pneumonia: a systematic review and meta-analysis

Predicting stroke-associated pneumonia (SAP) is crucial for intensifying preventive measures and decreasing morbidity and mortality. This meta-analysis aims to evaluate the association between baseline neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR) with SAP and to determine the strength of the association. The Web of Science, SCOPUS, and PUBMED databases were searched to find eligible studies. The standardised mean difference (SMD) and 95% confidence interval (CI) were used to evaluate the differences in NLR, MLR, and PLR levels between SAP and non-SAP patients. The meta-analysis was conducted using the software "Review Manager" (RevMan, version 5.4.1, September 2020). The random-effect model was used for the pooling analysis if there was substantial heterogeneity. Otherwise, the fixed-effect model was adopted. Twelve studies comprising 6302 stroke patients were included. The pooled analyses revealed that patients with SAP had significantly higher levels of NLR, MLR, and PLR than the non-SAP group. The SMD, 95% CI, p-value, and I2 for them were respectively reported as (0.88, 0.70-1.07, 0.00001, 77%); (0.94, 0.43-1.46, 0.0003, 93%); and (0.61, 0.47-0.75, 0.001, 0%). Subgroup analysis of NLR studies showed no significant differences in the effect size index between the severity of the stroke, the sample size, and the period between the stroke onset and the blood sampling. This systematic review and meta-analysis suggest that an elevated NLR, MLR, and PLR were associated with SAP, indicating that they could be promising blood-based biomarkers for predicting SAP. Large-scale prospective studies from various ethnicities are recommended to validate this association before they can be applied in clinical practice.</p

Principal component analysis results for MARS and BMQ-specific for parents and children.

<p>Principal component analysis results for MARS and BMQ-specific for parents and children.</p

Beliefs about medication descriptive statistics.

<p>Beliefs about medication descriptive statistics.</p

Parent reported adherence of their child to their medication [n = 249].

<p>Parent reported adherence of their child to their medication [n = 249].</p

Pearson Product Moment Correlation between MARS, BMQ-specific at Time 1 and Time 2.

<p>Pearson Product Moment Correlation between MARS, BMQ-specific at Time 1 and Time 2.</p

Reliability coefficient.

<p>Reliability coefficient.</p

Test–retest reliability as assessed by ICC for MARS, BMQ-specific Items for parents and children.

<p>Test–retest reliability as assessed by ICC for MARS, BMQ-specific Items for parents and children.</p

Demographic characteristics of the participants.

<p>Demographic characteristics of the participants.</p

Scatter plot showing the four different clusters formed after hierarchical clustering of the ALL study sample using 20th percentile of metabolite levels as cutoff point.

<p>Data for 6-mMPNs and 6-TGNs are the metabolite levels (adjusted per dose/SA). Cluster A (i.e. above 20% cutoff point) was characterized by high levels of 6-TGN levels and 6-mMP levels (adherent patients). Cluster B was characterized by high levels of 6-mMP but with low 6-TGN concentrations, it is expected that those patients in Cluster B had higher TPMT activity than those in cluster A, which would explain the shift in 6-MP metabolism toward 6-mMP production in those patients. Cluster C was characterized by low levels of both 6-mMP levels and 6-TGN (non-adherent patients). Cluster D patients have low levels of 6-mMP levels and high levels of 6-TGN (Lower TPMT activity in patients in Cluster D compared to those in cluster A would explain the shift in 6-MP metabolism toward 6-TG production in those patients).</p

Distribution of the total scores for the MARS questionnaires reported by participating parents and children.

<p>Distribution of the total scores for the MARS questionnaires reported by participating parents and children.</p