Diagnostic value of transcranial sonography for patients with Parkinson’s disease in the chinese population：A meta and meta-regression analysis

Background: To evaluate the diagnostic accuracy of substantia nigra hyper-echogenicity by transcranial sonography (TCS) for the diagnosis of Parkinson’s disease (PD) in the Chinese population. Methods: We searched the electronic databases of Cochrane Central Register of Controlled Trials (CENTRAL), Pubmed, Embase, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Database (CBM) up to Dec 2018 for related articles. All the published population-based studies investigating diagnostic value of TCS for PD patients in China were searched and evaluated. A meta and meta-regression analysis was performed to calculate the available data from each research. Meta—Disc 1.4 statistics software was used. Results: 23 studies with 1478 PD patients were analyzed. The pooled sensitivity, specificity, positive likelihood radio (LR+), negative 1ikellhood ratio (LR-) and diagnostic odds ratio (DOR) of TCS were 0.78 (95% confidence interval (CI): 0.75, 0.80), 0.87 (95% CI: 0.85, 0.89), 6.74 (95% CI: 5.04, 8.31), 0.23 (95% CI: 0.19, 0.28) and 31.32 (95% CI: 21.28, 46.09), respectively, for differentiating PD patients from healthy controls. The AUC and Q index was 0.9119 and 0.8442, respectively. In the subgroup and meta-regression analysis, we found that the important cause of heterogeneity was the sample size of PD patients (P=0.0051). Conclusion: TCS is an effective and useful tool to detect and distinguish PD from healthy controls in the Chinese individuals.