Evaluation of P-POSSUM scoring system in predicting mortality in patients with hip joint arthroplasty

Objective: To evaluate the applicability of Porthsmouth modified physiological and operative severity score for the enumeration of mortality and morbidity (P-POSSUM) in predicting the mortality of the patients undergoing hip joint arthroplasty. Methods: A total of 141 patients (75 males and 66 females, aged 63.22 years± 14.45 years on an average) undergoing hip joint arthroplasty during January 2002 and March 2005 were studied retrospectively with P-POSSUM. Their average physiological score and operative severity score were 17.48±5.16 and 12.43±3.05, respectively. The predicted postoperative mortality with P-POSSUM was compared with the observed value. Subgroup analysis was performed to investigate the predictive capability of P-POSSUM. POSSUM scoring system was used as the control. Results: Three patients died after operation in this study actually. The average physiological scores were 32.33±9.87 in the death group and 17.16±4.56 in the survival group. The former was obviously higher than the latter, which showed statistical difference between the two groups (Wilcoxon rank sum test, P<0.05). Perfect agreement was found between the observed death number and the predicted death number calculated by P-POSSUM (Cochran-Mantel-Haenszel 2 test, P>0.05), though POSSUM overestimated the overall mortality. Conclusions: P-POSSUM can predict the mortality accurately in the patients undergoing hip joint arthroplasty, which is superior to POSSUM.