Table 1.

Red cell distribution width/platelet ratio in non-hepatic conditions

Ref.	Method	Findings	Conclusion
Acute conditions
Cetinkaya et al[43], 2014	Totally 102 patients with AP were recruited	RPR with a cutoff value of 0.000067 presented an area under the receiver operating characteristic curve of 0.783 (95%CI: 0.688-0.878) and predicted the mortality of approximately 80% of the patients	RPR is a valuable biomarker of mortality in AP
Pusuroglu et al[44], 2015	Totally 470 consecutive patients with STEMI submitted for primary PCI were prospectively enrolled	At LRA, high RPR was an independent predictor of one-year cardiovascular mortality (P = 0.003, OR = 3.106, 95%CI: 1.456-6.623)	RPR is an inexpensive and readily available biomarker which offers additional risk stratification in predicting long-term MACE and cardiovascular mortality in STEMI
Celık et al[42], 2015	Totally 580 STEMI patients were divided into two groups according to thrombolysis in myocardial infarction flow grades after primary PCI	At LRA, RPR was among the independent predictors of no-reflow after primary PCI. In its turn, being in the no-reflow group compared to the reflow patients was associated with higher odds of in-hospital MACE, and cardiovascular mortality	RPR is among the independent predictors of no-reflow and in-hospital MACE among patients with STEMI undergoing primary PCI
Karabulut and Arcagok[45], 2020	RPR was compared to C-reactive protein and procalcitonin to investigate the potential to predict EOS in newborns	RPR and other biomarkers had higher values in proven EOS than in the controls	RPR may be used in the diagnosis of EOS among newborns as a good alternative to other tools
Lehmann et al[46], 2021	Totally 102 subjects with deep-seated ICH were included	At LRA elevated RPR ≥ 0.06 was among the independent predictors of 90-day mortality	RPR, as a biomarker of inflammation, might serve for prognostic assessment in deep-seated ICH
Jiang et al[47], 2022	Totally 47 individuals with MSA, 125 subjects with Parkinson’s disease, and 124 healthy controls were enrolled	At LRA, RPR was associated with the risk of MSA	Patients with MSA probably have peripheral inflammatory reaction
Liu et al[48], 2022	Totally 3367 patients with sepsis were enrolled	After adjustment for confounders, high RPR was significantly associated with increased mortality both for categorical and continuous variables (adjusted HR = 1.210, 95%CI: 1.045–1.400; and adjusted HR = 2.826, 95%CI: 2.025–3.944, respectively)	Elevated RPR values predict 28-day mortality in patients with sepsis
Wang et al[49], 2022	Totally 45 newborns were included in each of three groups of different severity; mild, moderate, and severe conditions based on SNAPE-II	A positive correlation was found between the SNAPE-II scores and RPR among newborns in NICU	Further to the SNAPE-II, also RPR can be used as a supplementary predictor biomarker for the assessment of neonatal morbidity and mortality in NICU
Liang et al[50], 2023	Retrospective cohort study of 2823 adults with ICH	After adjustment for confounding factors, the 3rd tertile of RPR values, compared to the 1st tertile, was associated with increased odds of 30-day death in patients with ICH (HR = 1.37, 95%CI: 1.15–1.64)	Among subjects with ICH, elevated RPR levels predict 30-day mortality
Kasirer et al[51], 2024	Totally 69 infants with NEC and 78 controls were enrolled	RPR was significantly associated with both NEC diagnosis (P < 0.0001) and mortality (P = 0.01). However, at LRA only variations of platelet count from birth to diagnosis remained significant	The often-elusive attempts to definitively diagnose NEC among preterm newborns may benefit from largely available, cheap, and easily calculated platelet indices
Chronic and acute-on chronic conditions
Özer Bekmez et al[52], 2018	A cohort of 112 infants with medically treated hsPDA and 96 controls were recruited	At LRA analysis, high RPR (OR = 3.3, 95%CI: 1.438-5.872, P < 0.05) was one of the independent risk factors for hsPDA	RPR is a promising biomarker for the diagnosis of hsPDA
Bilgin et al[53], 2019	Totally 312 CRC patients were enrolled	Among subjects with right-sided advanced cancer, OS was statistically significantly better for those with RPR ≥ 0.05 compared to those with RPR < 0.05 (median OS; RPR ≥ 0.05: 24.8 months vs < 0.05: 13.9 months; P = 0.035)	After validation, RPR can be used as a prognostic marker in CRC
Dagistan and Cosgun[54], 2019	Retrospective survey of 1342 subjects submitted to cranial MRI	A statistically significant difference was found in RPR values among the various study groups (Fazekas 0 to Fazekas 3) (P < 0.001)	Increased RPR values may suggest higher Fazekas's score and dementia in cranial MRI studies
Guler Kazanci et al[55], 2019	Totally 481 infants were recruited (169 with hsPDA and 312 controls)	RPR was significantly higher in the hsPDA group (P < 0.05). At LRA RPR > 0.070 (risk ratio = 5.33; 95%CI: 3.28-8.65; P < 0.001) was among the independent predictors of hsPDA	High RPR values in the first hours of life are a risk factor for hsPDA (and hsPDA refractive to ibuprofen treatment) in preterm infants
Chen et al[56], 2023	Totally 1922 AECOPD adults participating in the MIMIC-III and MIMIC-IV; and 1738 AECOPD patients from Emergency Intensive Care Unit Collaborative Research Database were recruited	After adjusting for confounders, Log (RPR×1000) was associated with elevated risk of in-hospital mortality of AECOPD patients (OR = 1.36, 95%CI: 1.01–1.84)	Among AECOPD patients RPR was associated with in-hospital mortality

AECOPD: Acute exacerbations of chronic obstructive pulmonary disease; AP: Acute pancreatitis; CRC: Colorectal cancer; EOS: Early onset sepsis; HR: Hazard ratio; ICH: Intracerebral hemorrhage; HsPDA: Hemodynamically significant patent ductus arteriosus; LRA: Logistic regression analysis; MACE: Major adverse cardiovascular events; MIMIC: Medical Information Mart for Intensive Care; MSA: Multiple system atrophy; MRI: Magnetic resonance imaging; NEC: Necrotizing enterocolitis; NICU: Neonatal intensive care units; OR: Odds ratio; OS: Overall survival; PCI: Percutaneous coronary intervention; RPR: Red cell distribution width/platelet ratio; SNAPE-II: Score for neonatal acute physiology and perinatal extension II; STEMI: ST-segment elevation myocardial infarction.