OBJECTIVE: The meta-analysis was to determine the diagnostic value of the combining tests for Down syndrome and to evaluate their utilities in the Down syndrome screening. METHOD: Through comprehensive literature search, 24 studies met the inclusion criteria and were included in the databases (PubMed, Wed of knowledge, Chinese National Knowledge Infrastructure (CNKI)). Summary estimates for sensitivity and specificity were calculated by using the bivariate random effect model. The summary receiver operating characteristic curve was also undertaken. RESULTS: The overall sensitivity and specificity of the combination of NT and free β-hCG and PAPP-A for Down syndrome were 0.86(95%CI 0.75-0.92) and 0.96(95%CI 0.95-0.97), respectively. The summary positive likelihood ratio and negative likelihood ratio were 23.3 (95%CI 16.7-32.5) and 0.15(95%CI 0.08-0.26), respectively. The pooled diagnostic odds ratio was 156 (95%CI 75-326). CONCLUSION: The meta-analysis shows the accumulative evidence for the clinician that the performance of the combined test of MA and NB and NT and PAPP-A and free β-hCG is the most effective test in the four different combined tests, while, the combination of NT and PAPP-A and free β-hCG is a cost-effective screening tool for Down syndrome.
OBJECTIVE: The meta-analysis was to determine the diagnostic value of the combining tests for Down syndrome and to evaluate their utilities in the Down syndrome screening. METHOD: Through comprehensive literature search, 24 studies met the inclusion criteria and were included in the databases (PubMed, Wed of knowledge, Chinese National Knowledge Infrastructure (CNKI)). Summary estimates for sensitivity and specificity were calculated by using the bivariate random effect model. The summary receiver operating characteristic curve was also undertaken. RESULTS: The overall sensitivity and specificity of the combination of NT and free β-hCG and PAPP-A for Down syndrome were 0.86(95%CI 0.75-0.92) and 0.96(95%CI 0.95-0.97), respectively. The summary positive likelihood ratio and negative likelihood ratio were 23.3 (95%CI 16.7-32.5) and 0.15(95%CI 0.08-0.26), respectively. The pooled diagnostic odds ratio was 156 (95%CI 75-326). CONCLUSION: The meta-analysis shows the accumulative evidence for the clinician that the performance of the combined test of MA and NB and NT and PAPP-A and free β-hCG is the most effective test in the four different combined tests, while, the combination of NT and PAPP-A and free β-hCG is a cost-effective screening tool for Down syndrome.