BACKGROUND: The Portsmouth Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (P-POSSUM) equation permits comparative audit that allows for differences in case mix. The methodology has previously been shown accurately to model general surgical and vascular surgical @entity1 . @entity1 with a @entity1755 ( @entity1028 ) are, however, very different from elective @entity1 and it may be hypothesized that they require their own specific risk model. METHODS: POSSUM data on 444 (213 emergency, 231 elective) admissions for @entity1028 surgery between August 1993 and July 2000 were analysed using the P-POSSUM equation for general surgery and the P-POSSUM equations developed for vascular surgery. RESULTS: All equations successfully modelled the elective @entity439 but failed to fit the @entity439 , and the elective and @entity439 combined. This suggested that admission method (not a POSSUM data item) is an important factor for @entity1 with @entity1028 . However, with these data it was not possible to generate a model, including admission method, that successfully modelled the combined elective and emergency data. The 213 emergency aneurysm repairs were divided into two groups by operation date. The first 106 (training set) were used to form logistic regression models following the P-POSSUM methodology. These models were found successfully to fit the remaining 107 records (test set) on prospective application (chi2 = 4.50, 4 d.f., P = 0.345). CONCLUSION: Ruptured AAAs appear to be different from elective AAAs and other vascular cases and require their own risk model.

Portsmouth POSSUM models for XXXX surgery.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity439 :: ('MESH:D000783', 'Disease') :: ['emergency aneurysms', 'aneurysms'] @entity1028 :: ('MESH:D017544', 'Disease') :: ['AAA'] @entity1755 :: ('MESH:D001019', 'Disease') :: ['ruptured abdominal aortic aneurysm']
@entity1028 :: (MESH:D017544,Disease) :: ['abdominal aortic aneurysm']
