Diagnostic accuracy of pleural fluid NT-pro-BNP for pleural effusions of cardiac origin: a systematic review and meta-analysis

Table 2 Diagnostic accuracy variables of the studies included in the meta-analysis.

Study	No. Pts/Pes	TP	FN	TN	FP	Se	Sp	NT-pro-BNP Threshold*	Average NT-pro-BNP^†	Misclassification		Correlation Statistic^∏
										Light's^‡	NT-pro-BNP^§
Tomcsanyi et al[16]	28	14	0	14	0	100%	100%	≥ 599^¶	8236	1/14 (7%)	0/1	R ² = 0.95 p < 0.0001
Porcel et al[17]	117	40	4	68	5	91%	93%	≥ 1500	6931	10/35 (29%)	2/10	NR
Kolditz et al[18]	93	23	2	63	5	92%	93%	≥ 4000	10427	9/25 (36%)	0/9	S = 0.96 p < 0.001
Porcel et al[19]	93	49	4	35	5	92%	87%	≥ 1500	6106	8/53 (15%)	2/8	S = 0.96 p < 0.001
Liao et al[20]	40	10	0	29	1	100%	97%	≥ 2220	5390	NR	NR	NR
Han et al[21]	240	81	1	156	2	99%	99%	≥ 1714	3310	28/82 (34%)	1/28	R ² = 0.93 p < 0.001
Seyhan et al[22]	115	47	4	61	3	92%	95%	≥ 1092	N/A	17/51 (33%)	N/A	N/A
Porcel et al[23]	181	84	6	81	10	93%	89%	≥ 1500	6203	20/90 (22%)	4/20	NR
Bayram et al[24]	133	48	3	78	4	94%	95%	≥ 925	4468	19/51 (37%)	0/19	R ² = 0.91 p < 0.001
Long et al[25]	80	16	4	44	16	80%	73%	≥ 2000	4189	NR	NR	NR

* = pleural fluid NT-pro-BNP threshold in pg/mL; † = average pleural fluid NT-pro-BNP in CHF effusions in pg/mL; ‡ = misclassification of CHF effusions as exudates by Light's criteria; § = misclassification of the CHF effusions already misclassified by Light's criteria now misclassified by NT-pro-BNP; ∏ = correlation between serum and pleural fluid NT-pro-BNP levels; ¶ = threshold from 599 to 1457 pg/mL resulted in 100% sensitivity and specificity; N/A = not available because only abstract available for data extraction; No. = number; NR = not recorded; Pes = pleural effusions; Pts = patients; R ² = Pearson coefficient of correlation; S = Spearman's coefficient of rank correlation; Se = sensitivity; Sp = specificity.