Four early warning scores predict mortality in emergency surgical patients at University Teaching Hospital, Lusaka: a prospective observational study

  • Katie Ellen Foy
  • Janaki Pearson
  • Laura Kettley
  • Niharika Lal
  • Holly Blackwood
  • M. Dylan BouldEmail author
Reports of Original Investigations



The value of early warning scoring systems has been established in high-income countries. There is little evidence for their use in low-resource settings. We aimed to compare existing early warning scores to predict 30-day mortality.


University Teaching Hospital is a tertiary center in Lusaka, Zambia. Adult surgical patients, excluding obstetrics, admitted for > 24 hr were included in this prospective observational study. On days 1 to 3 of admission, we collected data on patient demographics, heart rate, blood pressure, oxygen saturation, oxygen administration, temperature, consciousness level, and mobility. Two-, three-, and 30-day mortality were recorded with their associated variables analyzed using area under receiver operating curves (AUROC) for the National Early Warning Score (NEWS); the Modified Early Warning Score (MEWS); a modified Hypotension, Oxygen Saturation, Temperature, ECG, Loss of Independence (mHOTEL) score; and the Tachypnea, Oxygen saturation, Temperature, Alertness, Loss of Independence (TOTAL) score.


Data were available for 254 patients from March 2017 to July 2017. Eighteen (7.5%) patients died at 30 days. The four early warning scores were found to be predictive of 30-day mortality: MEWS (AUROC, 0.76; 95% confidence interval [CI], 0.63 to 0.88; P < 0.001), NEWS (AUROC 0.805; 95% CI, 0.688 to 0.92; P < 0.001), mHOTEL (AUROC 0.759; 95% CI, 0.63 to 0.89, P < 0.001), and TOTAL (AUROC 0.782; 95% CI, 0.66 to 0.90; P < 0.001).


We validated four scoring systems in predicting mortality in a Zambian surgical population. Further work is required to assess if implementation of these scoring systems can improve outcomes.

Quatre scores d’évaluation d’alerte précoce pour prédire la mortalité des patients chirurgicaux d’urgence au Centre hospitalier universitaire de Lusaka : une étude observationnelle prospective



L’utilité des scores d’évaluation d’alerte précoce a été établie dans les pays à revenu élevé. Il n’existe que peu de données probantes concernant leur utilisation dans les contextes de faibles ressources. Nous avons tenté de comparer les scores d’évaluation d’alerte précoce existants en fonction de leur capacité à prédire la mortalité à 30 jours.


Le University Teaching Hospital est un centre de soins tertiaires à Lusaka, en Zambie. Les patients chirurgicaux adultes, y compris en obstétrique, admis pour plus de 24 h ont été inclus dans cette étude observationnelle prospective. Au cours des 3 premiers jours suivant l’admission, nous avons récolté des données concernant les patients, soit les données démographiques, leur fréquence cardiaque, leur tension artérielle, leur saturation en oxygène, l’administration d’oxygène, la température, le niveau d’éveil et la mobilité. La mortalité à deux, trois et 30 jours a été enregistrée accompagnée des variables associées, analysées à l’aide des surfaces sous la courbe de fonction d’efficacité de l’observateur (SSC-ROC) pour les scores d’évaluation suivants : NEWS (National Early Warning Score, soit Score national d’alerte précoce), MEWS (Modified Early Warning Score, soit Score modifié d’alerte précoce), mHOTEL (un score modifié évaluant l’hypotension, la saturation en oxygène, la température, l’ECG et la perte d’indépendance), et le score TOTAL (tachypnée, saturation en oxygène, température, vigilance et perte d’indépendance).


Les données étaient disponibles pour 254 patients hospitalisés entre mars 2017 et juillet 2017. Dix-huit (7,5 %) patients sont décédés à 30 jours. Nous avons observé que les quatre scores d’évaluation d’alerte précoce permettaient de prédire la mortalité à 30 jours : MEWS (SSC-ROC, 0,76; intervalle de confiance [IC] 95 %, 0,63 à 0,88; P < 0,001), NEWS (SSC-ROC 0,805; IC 95 %, 0,688 à 0,92; P < 0,001), mHOTEL (SSC-ROC 0,759; IC 95 %, 0,63 à 0,89, P < 0,001), et TOTAL (SSC-ROC 0,782; IC 95 %, 0,66 à 0,90; P < 0,001).


Nous avons validé quatre scores d’évaluation pour prédire la mortalité dans une population chirurgicale zambienne. Des travaux supplémentaires sont nécessaires afin d’évaluer si la mise en œuvre de ces scores d’évaluation peut améliorer les devenirs.



We thank Dr. Hazel Mumphansha, Dr. Naomi Shamambo, and Dr. Zubair Rakhda for their input into the development of this study. Thank you to the administration of University Teaching Hospital, Zambia for supporting the work. Thank you to all research assistants for their contribution to data collection.

Conflicts of interest

None declared.

Editorial responsibility

This submission was handled by Dr. Hilary P. Grocott, Editor-in-Chief, Canadian Journal of Anesthesia.

Author contributions

Katie Ellen Foy contributed to study design, data acquisition, data analysis and wrote the manuscript. Janaki Pearson and Laura Kettley contributed to study conception and design, acquisition of ethics approval, data analysis and editing of the manuscript. Niharika Lal contributed to study design, data acquisition, data analysis and interpretation and editing of the manuscript. Holly Blackwood contributed to study conception and design. M. Dylan Bould contributed to study conception and design, data analysis, drafting and editing of the manuscript and was the supervising clinician. All authors gave final approval of the version to be published.


This work was funded by the Zambia Anesthesia Development Program who in turn have received funding from the Tropical Health and Education Trust and the UK Department for International Development.


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Copyright information

© Canadian Anesthesiologists' Society 2019

Authors and Affiliations

  1. 1.Department of AnaesthesiaBristol Royal InfirmaryBristolUK
  2. 2.Department of AnaesthesiaSunderland Royal HospitalSunderlandUK
  3. 3.Department of AnaesthesiaRoyal Alexandra HospitalPaisleyUK
  4. 4.Department of PediatricsPinderfields HospitalWakefieldUK
  5. 5.Department of Anesthesiology and Pain MedicineChildren’s Hospital of Eastern OntarioOttawaCanada

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