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Prospective Evaluation of In-hospital Mortality with the P-POSSUM Scoring System in Patients Undergoing Major Digestive Surgery

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Abstract

Background

The P-POSSUM score, the most well known of predictive scores for postoperative mortality, requires validation for population and setting.

Methods

Validation methods included discrimination (C-index statistic), observed:expected (O:E) ratio, calibration with the Hosmer-Lemeshow test, and subgroup analysis (emergency surgery, cancer, age, organs). The study included 3,881 multisite patients undergoing major digestive surgery in France.

Results

Discrimination via the receiver operating characteristic curve was good (C-index = 0.87). The overall O:E ratio was 1 (95% confidence interval ([95 % CI]: 0.88–1.13), and therefore the quality of the surgical performance is within normal ranges. The O:E ratio, calculated by risk ranges, showed overestimation in the low risk range, especially in the 3 % to 6 % and 6 % to 10 % ranges. Calibration was poor (p < 0.001). The model deviated from the normal pattern of calibration, with mortality lower than expected in the high-risk range. Subgroup analysis found reasonable to good discrimination of populations (C-index ranging from 0.78 to 0.93 except for liver surgery [0.67]) while calibration of individuals remained poor (p < 0.001 to 0.02).

Conclusions

Good discrimination, as well as nonsignificant overall O:E values, makes P-POSSUM a valuable tool when it is used for surgical audit to compare mortality between populations for major digestive surgery. Conversely, poor calibration (goodness-of-fit), especially in subgroup analysis, and underestimation or overestimation of O:E ratios considerably limits the value of P-POSSUM for prediction of mortality in individuals. Therefore P-POSSUM should not be used to predict outcomes for one particular patient.

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Acknowledgments

This work was supported by three grants: Haute Autorité de Santé (HAS) GJ/SF/109-05 PR 01-010. Programme Hospitalier de Recherche Clinique (PHRC) Appel d’offre Régional (AOR) 03-013. Ligue Nationale contre le Cancer (LNCC) PRC-2003-LNCC/JMH1. The following were contributing surgeons and participating units: Brassier, Didier (Aulnay/Bois); Collet, Denis (Pessac/Bordeaux), DeCalan, Loic (Tours), Decker, Georges (Luxembourg), Bakoto, A (Chateauroux), Descottes, Bernard (Limoges), Demaizières, François (Paray-le-Monial), Desrousseaux, Bruno (Lomme), Desvignes, Gérard (Montargis Amilly), Dilin, Christian (Thonon les Bains), Ducerf, Christian (Lyon), Evrard, Serge (Bordeaux), Fabre, Xavier (Cholet), Flamant, Yves (Colombes), Fingerhut, Abe (Poissy), Fourtanier, Gilles (Toulouse), Gabelle, Philippe (Grenoble), Gainant, Alain (Limoges), Gayet, Brice (Paris), Hennet, Henri (Romorantin), Herbiere, Patrick (Albi), Herjean, Marion (Valenciennes), Ianelli, Antonio (Menton), Jaeck, Daniel (Strasbourg), Kohlmann, Gérard (Corbeil-Essonne), Laborde, Yves (Pau), Lehur, Paul-Antoine (Nantes), Langlois-Zantain, Odile (Montluçon), Leynaud, Gérard (Montluçon), Merad, Fehti (Poissy/Eaubonne/Alger), Michot, François (Rouen), Oberlin, Philippe (Villeneuve St Georges), Pellissier, Edouard (Besançon), Pessaux, Patrick (Angers), Peyrard, Pierre (Compiegne), Philippe, Olivier (Orange), Pujol, José (Bergerac), Regimbeau, Jean-Marc (Amiens), Rey, Claude (Vernon), Sage, Michel (Auxerre), Segol, Philippe (Caen), Tarla, Emmanuel (Cannes), Tison, Marc (Dunkerque), Triboulet, Jean-Pierre (Lille), Troalen, Karen (Gonesse), Vacher, Bernard (Argenteuil), Veyrières, Michel (Pontoise).

Conflict of interest

None of the authors has any conflict of interest with respect to the contents or the writing of the manuscript.

Ethical approval

As completely anonymous patient data recording took place all throughout the study, no ethics board or IRB approval was deemed necessary for this study.

Author information

Authors and Affiliations

  1. Unit of General and Digestive Surgery, Hôpital Louis Mourier, Assistance Publique Hôpitaux de Paris, Colombes, France

    Féthi Merad & Jean-Marie Hay

  2. National Institute of Health and Medical Research (INSERM), U738, Paris, France

    Gabriel Baron & Philippe Ravaud

  3. Centre d’Epidémiologie Clinique, Hôpital Hôtel Dieu, AP-HP, Université Paris Descartes, Paris, France

    Gabriel Baron & Philippe Ravaud

  4. Department of Epidemiology, Biostatistics and Clinical Research, Hôpital Bichat, Assistance Publique Hôpitaux de Paris, Paris, France

    Blandine Pasquet

  5. Surgical Unit Centre Hospitalier, Romorantin, France

    Henry Hennet

  6. Surgical Unit Centre Hospitalier, Corbeil-Essonnes, France

    Gérard Kohlmann

  7. Surgical Unit Centre Hospitalier, Argenteuil, France

    Fred Warlin

  8. Surgical Unit Centre Hospitalier Universitaire, Lomme, France

    Bruno Desrousseaux

  9. First Department of Surgery, Hippocration Hospital, University of Athens Medical School, Athens, Greece

    Abe Fingerhut

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  1. Féthi Merad
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Corresponding author

Correspondence to Abe Fingerhut.

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Merad, F., Baron, G., Pasquet, B. et al. Prospective Evaluation of In-hospital Mortality with the P-POSSUM Scoring System in Patients Undergoing Major Digestive Surgery. World J Surg 36, 2320–2327 (2012). https://doi.org/10.1007/s00268-012-1683-0

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