Table 3.

Definitions of perioperative mortality rate

	Number of papers (%)
Numerator
Clearly defined	455 (46.2)
Inpatient/hospital mortality (assumed for all studies lacking clear definition)	703 (71.4)
Inpatient/hospital mortality, within 30 days of procedure	13 (1.3)
30-day mortality	202 (20.5)
Mortality within 30 days or same hospitalisation	32 (3.3)
7-day mortality	3 (0.3)
Intraoperative mortality	14 (1.4)
24 hours mortality	4 (0.4)
Other	14 (1.4)
Multiple	24 (2.4)
Denominator
Number of patients	969 (98.4)
Number of procedures	16 (1.6)

Most studies did not explicitly state the timeframe during which deaths accrued. For those studies lacking clear time definitions, deaths were assumed to accrue during the index hospitalisation alone.