Combined and intraoperative risk modelling for oesophagectomy: A systematic review

Table 4 Methodological quality (overall performance) for combined and intraoperative models

Model	Study participation (out of 8)	Measurements (out of 4)	Analysis (out of 8)	Total (out of 20)
POSSUM	7	3	5.5	15.5
O-POSSUM	8	4	8	20
P-POSSUM	7	3	7	17
E-PASS	7.5	3	6	16.5
Yoshida score	6	4	6	16.5
Xi SAS nomogram	8	4	7	19
Xi IPF nomogram	8	4	6	18
Huang model	7.5	4	6	16.5
SAS	8	4	7	19
eSAS	8	4	4	16
Modified eSAS	8	4	6	17.5

POSSUM: Physiological and operative severity score for the enumeration of mortality and morbidity; P-POSSUM: Portsmouth physiological and operative severity score for the enumeration of mortality and morbidity; O-POSSUM: Oesophagogastric physiological and operative severity score for the enumeration of mortality and morbidity; E-PASS: Estimation of physiologic ability and surgical stress; SAS: Surgical Apgar score; eSAS: Esophagectomy surgical Apgar score.