Table 1.
The search terms used in systematic review.
Fig 1.
The process of study search and selection.
Table 2.
The characteristics of included study and population.
Table 3.
Diagnostic value of blood NGAL, urine NGAL and serum cystatin C to predict CIN in each study.
Fig 2.
The methodological quality assessment.
The methodological quality of included studies was assessed according to the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool.
Fig 3.
Coupled forest plots for the pooled sensitivity and specificity of blood NGAL for the diagnosis of CIN.
Dots in squares represent sensitivity and specificity. Horizontal lines represent the 95% confidence interval (CI) for each included study. The pooled estimate is based on the random-effects model. Heterogeneities evaluation, I2 with 95% CIs and Q are provided. Q is Cochrane heterogeneity statistic and df is the degrees of freedom.
Fig 4.
Coupled forest plots for the pooled sensitivity and specificity of serum cystatin C for the diagnosis of CIN.
Dots in squares represent sensitivity and specificity. Horizontal lines represent the 95% confidence interval (CI) for each included study. The pooled estimate is based on the random-effects model. Heterogeneities evaluation, I2 with 95% CIs and Q are provided. Q is Cochrane heterogeneity statistic and df is the degrees of freedom.
Fig 5.
Hierarchical summary receiver operating characteristic (HSROC) curve for blood NGAL, urine NGAL and serum cystatin C for the diagnosis of CIN.
The black, green and red dots present the summary points for serum cystatin C, blood NGAL and urine NGAL respectively. The area circled by dot-dashed lines represent 95% confidence region; the area circled by dashed lines represent 95% prediction region.
Table 4.
Subgroup analysis of diagnostic performance for index tests in different measuring time.
Fig 6.
Deek’s funnel plot asymmetry test for publication bias of blood NGAL(a), urine NGAL(b) and serum cystatin C(c). There was no considerable publication heterogeneity in each group.