Table 3. Positive predictive value of heart failure admission after implantable cardioverter-defibrillator (ICD) or cardiac resynchronisation therapy (CRT) in the Danish National Patient Registry, compared with medical record review, 2017–2022.

Heart failure admission	First-time heart failure		Positive predictive value (95% CI), %
	Confirmed, n	Reviewed, n
After implantable cardioverter-defibrillator (ICD)
In or outpatient	18	71	25 (16–37)
Inpatient	8	21	38 (18–62)
Outpatient	10	50	20 (10–34)
After cardiac resynchronization therapy (CRT)
In or outpatient	11	62	18 (9.2–30)
Inpatient	5	13	38 (14–68)
Outpatient	6	49	33 (20–48)

Abbreviation: CI, confidence interval.