Coding systems for HD data in Austria, England, Germany, Italy and Slovenia, MedtecHTA partners, were described (Table 1); lists of procedural codes for PMs and ICDs were compared and cross-referenced, identifying 16 device categories—implants and replacements of single chamber, dual chamber, and biventricular or cardiac resynchronization therapy (CRT) devices plus an additional unspecified device category found in some of the coding systems (Supplementary material online, Table S1 provides a list of all device variables and codes from the five countries). Codes regarding device removal or revisions or specifying only temporary or partial implantation (e.g. leads, loop recorders, temporary implants, pocket revisions) were excluded to identify only implants or replacements and avoid duplicates.