Evaluation of P-Possum mortality predictor equation and its use as a tool in surgical audit

Gopashetty, M and Rodrigues, Gabriel and Reddy, S and Shenoy, Gokuldas M (2002) Evaluation of P-Possum mortality predictor equation and its use as a tool in surgical audit. The Internet Journal of Surgery, 5 (1). pp. 1-7. ISSN 1528-8242

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"Physiological and Operative Severity Scoring system for enUmeration of Mortality"(POSSUM) and "Portsmouth" modification of POSSUM (P-POSSUM) are two scoring systems used to assess mortality exclusively in surgical patients. We wanted to study prospectively the accuracy of P-POSSUM mortality predictor equation in predicting in-patient mortality and compare "raw" mortality with risk adjusted mortality in six general surgery units of our hospital. Patients admitted and operated over a period of four months in six general surgery units of Kasturba Medical College and Hospital, Manipal, India were included in the study. Copeland's scoring system was used to classify patients and the data was analyzed using P-POSSUM mortality equation. Predicted mortality rate was calculated and was compared with observed mortality rate. Results were evaluated by χ2 test. A total of 493(n) patients were operated during this period of study. Of these, 103 patients underwent emergency surgeries. The mean physiological score was 18.93-(S.D.±8.05) and mean operative score was 10.54-(S.D. ±5.24). Among 493 patients operated, we had a mortality of 26. The raw mortality rate in surgical unit II was 3.96% and 5.45% in unit VI. It was lowest in unit V (1.69%) and highest in unit IV (6.41%). After adjusting for risk, it was noted that Observed:Expected mortality ratio was almost equal in unit II and unit VI (0.83 and 0.8 respectively), while it ranged from 0.66 in unit V to 1.25 in unit IV. It was also observed that mortality rates were not significantly different from predicted mortality rates (χ2 =0.75, 4 d.f*, p>0.5 [* degree of freedom]). Thus, at the end of the study it was concluded that P-POSSUM mortality predictor equation predicts death accurately in general surgical patients. Comparing risk adjusted mortality rate is more meaningful than comparing "raw" mortality rate.

Item Type: Article
Uncontrolled Keywords: Morbidity; mortality; surgical audit.
Subjects: Medicine > KMC Manipal > Surgery
Depositing User: KMC Manipal
Date Deposited: 25 Jun 2015 04:19
Last Modified: 25 Jun 2015 04:19
URI: http://eprints.manipal.edu/id/eprint/143127

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