Table 4.

Diagnostic accuracy results — hospitalized patients

Study	Algorithm description in the primary study	TP	FP	FN	TN	N total	Sn	95% CI Sn		Sp	95% CI Sp		PPV	95% CI PPV		NPV	95% CI NPV
Xu, 2020 [35]	X1 — ICD algorithm	170	14	126	1796	2106	57.4	51.8	63.0	99.2	98.8	99.6	92.4	88.6	96.2	93.4	92.3	94.5
	X2 — ICD algorithm in the nonsurgical patient cohort						60.0	54.2	65.8	99.1	98.6	99.6	93.2	89.5	96.9	92.1	90.7	93.5
Cozzolino, 2019 [36]	C1 — HF algorithm	119	8	5	71	203	96.0	91.0	99.0	90.0	81.0	96.0	94.0	88.0	97.0	93.0	85.0	98.0
Kaspar, 2018 [51]	K1 — ICD	110	7	112	813	1042	50.0	47.0	53.0	99.1	98.6	99.7	94.0	92.6	95.4	87.9	85.9	89.9
Bosco-Lévy, 2019 [50]	Diagnosis of HF in hospital discharge records	147		82		229	64.2	58.0	70.4
		176	24			200							88.0	83.5	92.5
Blecker, 2016 [52]	Bl1 — ICD9CM					315	71.4	66.4	76.4	98.7	97.4	100.0
Kümler, 2008 [53]	Ku1 — Diagnosis of HF	126	30	303	2742	3201	29.0	27.4	30.6	99.0	98.7	99.3	81.0	79.6	82.4	90.0	89.0	91.0
Quan, 2002 [54]	Q1 — ICD-9	99	14	29	1058	1200	77.3	74.9	79.7	98.7	98.1	99.3	87.6	85.7	89.5	97.3	96.4	98.2
Austin, 2002 [55]	A1 — ICD-9 most responsible diagnosis	3204	1707	2271	51,634	58,816	58.5	58.1	58.9	96.8	96.7	96.9	65.2	64.8	65.6	95.8	95.6	95.9
	A2 — ICD-9 most responsible or secondary	4676	8375	799	44,966	58,816	85.4	85.1	85.7	84.3	84.0	84.6	35.8	35.4	36.2	98.3	98.1	98.4
PPV only
Teng, 2008 [41]	Diagnosis of HF	1001	5			1006							99.5	99.1	99.9
Ingelsson, 2005 [43]	Diagnosis of HF	259	58			317							82.0	77.8	86.2
Lee, 2005 [44]	ICD-9	1547	94			1641							94.3	93.2	95.4

^aTwo different samples used to determine Sn (n total = 229, only with disease; not possible to compute Sp) and PPV (n total = 200, see note b). ^bStudies that selected a sample of patients positive to the algorithm and verified them to detect false positives only. Details on algorithms are reported in Supplementary Table S2 in Additional file 4