Table 2.

Endpoints in studies performing a risk prediction analysis in patients submitted to liver resection

Endpointe	Studies assessing the endpoint of interest, n	Studies defining the endpoint of interest, n
Mortality
Overall mortality	29	27a
Mortality from liver failure	3	3
Morbidity
Overall morbidity	43	33b
Severe morbidity	7	6
Organ dysfunction	1	1
Major infectious morbidity	1	1
Intraoperative complications
Operation time	1	1
Intraoperative blood transfusion	1	1
Liver-related complications
Hepatobiliary complications	1	1
Haemorrhage	1	1
Biliary complications	1	1
Liver failure	21	18c
Bile leak	5	4d
Biliary complications	1	1
Ascites	1	1
Acute renal failure	1	1
Pulmonary complications	1	1
Pleural effusion	1	1
Pneumonia	1	1
Pulmonary embolism	1	1
Infection	6	6
Surgical site infection	2	2
Intra-abdominal abscess	1	1
Blood transfusion during hospital stay	1	1
Systemic complications	1	1
Postoperative complications
Ventilation for >48 h	1	1
Reoperation	1	1
Length of stay	5	5

^aSix definitions of mortality were used, including 30-, 60- and 90-day, operative and in-hospital mortality and any death after surgery.

^bMultiple definitions of morbidity (when morbidity was defined) were used depending on severity (major as opposed to minor, specific, serious, resulting in organ failure, graded 3–5 on a scale of 1–5) origin (medical, surgical, both or unspecified) and timing (30-, 60- or 90-day, operative, in-hospital and after surgery).

^cLiver failure was defined by the association of many parameters including serum bilirubin, serum lactate, international normalized ratio, prothrombin time, encephalopathy, ascites, pleural effusion, varix, and time and delay of occurrence.

^dBile leak was defined by the association of many parameters including level of bilirubin and delay in occurrence.

^eSome studies analysed one or more endpoints of interest.