Prognostic role of haematological indices in sudden sensorineural hearing loss: Review and meta-analysis.

Background: Complete blood count (CBC) is an important blood test in clinical practice, and it has been recently used to predict the prognosis of patients with sudden sensorineural hearing loss (SSNHL). Some haematological indices of the CBC test have been reported to be associated with the clinical outcome of SSNHL. However, the prognostic value of these haematological indices in SSNHL is currently under debate. Here, we performed a meta-analysis to investigate the association between haematological indices of the CBC test and clinical outcomes in patients with SSNHL.

Methods: We conducted a meta-analysis of studies that evaluated the association between haematological indices and prognoses in patients with sudden hearing loss. Subgroup and sensitivity analyses were also performed to explore potential sources of heterogeneity.

Results: Ten studies that included 972 individuals were identified. Pooled analysis showed neutrophil-to-lymphocyte ratio (NLR) (weighted mean difference [WMD] = -1.69 and p < 0.001), platelet-to-lymphocyte ratio (PLR) (WMD = -38.45 and p < 0.001), neutrophil count (WMD = -1.57 × 10/L and p < 0.001) and lymphocyte count (WMD = 0.41 × 10/L and p < 0.001) to be the factors associated with the prognosis of SSNHL.

Conclusions: Our findings indicated that NLR, PLR, neutrophil count and lymphocyte count are strongly associated with the prognosis of SSNHL. These four indices could be recommended as inexpensive markers to report treatment outcomes.