Value of orthopedic POSSUM and P-POSSUM scoring system in predicting operation risk in aged patients with hip fracture

Objective To measure the value of orthopedic physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and Portsmouth modified POSSUM (P-POSSUM) scoring systems in predicting operative risks in aged hip fracture patients.Methods Orthopedic POSSUM and P-POSSUM were performed to predict complication incidence and mortality for 164 aged patients operated for hip fracture.Validation of the scoring systems was tested by assessing observed to expected ratio,discrimination,and calibration.Discriminative ability and calibration of both scores were estimated using receiver operation characteristic curve (ROC) and Hosmer-Lemeshow test respectively.Results Orthopedic POSSUM score performed in predicting incidence of postoperative complications showed overall observed to expected ratio of 0.86,area under the curve of 0.82,and good calibration (H2 =3.66,df=8,P ＞ 0.05).P-POSSUM performed in predicting mortality showed overall observed to expected ratio of 0.80,area under the curve of 0.93 and good calibration (H2 =3.21,df =4,P ＞ 0.05).While orthopedic POSSUM overestimated postoperative mortality (overall observed to expected ratio =0.27).Conclusion Orthopedic POSSUM and P-POSSUM scores are respectively accurate in predicting postoperative complication incidence and mortality in aged hip fracture patients,but orthopedic POSSUM score overestimates the mortality. Key words: Hip fractures;  Postoperative complications ;  Mortality ;  POSSUM/P-POSSUM scoring system