Table 3.

 Investigation of heterogeneity

Variables	Setting	Assay	Prevalence	Overall study quality
B type natriuretic peptide
≤100 ng/L:
Sensitivity (95% CI)	0.95 (0.91 to 0.97)	0.94 (0.91 to 0.96)	0.96 (0.92 to 0.98)	0.92 (0.84 to 0.96)
P value	0.89	0.6	0.5	0.13
Specificity (95% CI)	0.56 (0.38 to 0.72)	0.66 (0.49 to 0.79)	0.62 (0.36 to 0.83)	0.69 (0.43 to 0.87)
P value	0.51	0.76	0.96	0.64
100-500 ng/L:
Sensitivity (95% CI)	0.87 (0.82 to 0.91)	0.83 (0.77 to 0.88)	0.82 (0.71 to 0.90)	0.80 (0.68 to 0.88)
P value	0.37	0.68	0.62	0.29
Specificity (95% CI)	0.81 (0.69 to 0.89)	0.90 (0.81 to 0.95)	0.89 (0.73 to 0.96)	0.92 (0.78 to 0.97)
P value	0.38	0.45	0.65	0.36
N terminal probrain natriuretic peptide
≤300 ng/L:
Sensitivity (95% CI)	0.99 (0.97 to 0.99)	0.96 (0.77 to 0.99)	0.98 (0.93 to 1.00)	0.98 (0.90 to 1.00)
P value	0.97	0.21	0.81	0.56
Specificity (95% CI)	0.77 (0.57 to 0.89)	0.42 (0.06 to 0.89)	0.93 (0.84 to 0.97)	0.56 (0.15 to 0.90)
P value	0.53	0.37	<0.01*	058
N terminal probrain natriuretic peptide
300-1800 ng/L:
Sensitivity (95% CI)	0.90 (0.85 to 0.94)	0.92 (0.72 to 0.98)	0.93 (0.84 to 0.97)	0.91 (0.81 to 0.96)
P value	0.91	0.75	0.46	0.82
Specificity (95% CI)	0.78 (0.70 to 0.85)	0.58 (0.30 to 0.82)	0.84 (0.71 to 0.92)	0.78 (0.62 to 0.88)
P value	0.67	0.17	0.22	0.83