The African Surgical OutcomeS-2 (ASOS-2) Pilot Trial, a mixed-methods implementation study


  • Leon Du Toit University of Cape Town
  • Hyla-Louise Kluyts Sefako Makgatho Health Sciences University
  • Veekash Gobin Jawaharlal Nehru Hospital
  • Chaibou M Sani National Hospital of Niamey
  • Eugene Zoumenou Hôpital de la mère et de l'enfant
  • Akinyinka O Omigbodun University of Ibadan
  • Simbo D Amanor-Boadu University College Hospital
  • Sanogo Zimogo Zié CHU du POINT G
  • Andrew Ndonga Mater Hospital
  • Zipporah WW Ngumi University of Nairobi
  • Dolly M Munlemvo University Hospital of Kinshasa
  • Charles Copley
  • Dawid van Straaten Safe Surgery South Africa
  • Patrice Forget Vrije Universiteit Brussel
  • Rupert M Pearse Queen Mary University of London
  • Bruce M Biccard University of Cape Town


trial, cluster randomised, pilot, implementation science, mixed methods, mortality, surgery


Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. The working hypothesis is that patients die as a result of failure to rescue following complications in the postoperative period. The African Surgical OutcomeS-2 (ASOS-2) Trial plans to test the efficacy of increased postoperative surveillance in high risk patients for decreasing perioperative morbidity and mortality. This pilot trial aimed i) to evaluate the adequacy of data produced by the data collection strategies of the ASOS-2 Trial, ii) to evaluate the fidelity of implementation of the increased postoperative surveillance intervention, and iii) to understand the acceptability, appropriateness and feasibility of the intervention and the trial processes.

Methods: The ASOS-2 Pilot Trial was a mixed-methods (quantitative-qualitative) implementation study focusing on the intervention arm of the proposed ASOS-2 Trial. The intervention is increased postoperative surveillance for high-risk surgical patients. The intervention protocol was implemented at all sites for a seven-day period. A post pilot trial survey was used to collect data on the implementation outcomes.

Results: 803 patients were recruited from 16 hospitals in eight African countries. The sampling and data collection strategies provided 98% complete data collection. Seventy-three percent of respondents believed that they truly provided increased postoperative surveillance to high risk patients. In reality 83/125 (66%) of high-risk patients received some form of increased postoperative surveillance. However, the individual components of the increased postoperative surveillance intervention were implemented in less than 50% of high-risk patients (excepting increasing nursing observations). The components most frequently unavailable were the ability to provide care in a higher care ward (32.1%) and assigning the patient to a bed in view of the nurses’ station (28.4%). Failure to comply with available components of the intervention ranged from 27.5% to 54.3%. The post pilot survey had a response rate of 30/40 (75%). In Likert scale questions about acceptability, appropriateness, and feasibility of the ASOS-2 intervention, 63% to 87% of respondents indicated agreement. Respondents reported barriers related to resources, trial processes, teamwork and communication as reasons for disagreement.

Conclusions: The proposed ASOS-2 Trial appears to be appropriate, acceptable and feasible in Africa. This pilot trial provides support for the proposed ASOS-2 Trial. It emphasises the need for establishing trial site teams which address the needs of all stakeholders during the trial. A concerted effort must be made to help participating hospitals to increase compliance with all the components of the proposed intervention of ‘increased postoperative surveillance’ during the ASOS-2 Trial.

Author Biographies

Leon Du Toit, University of Cape Town

Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, South Africa

Hyla-Louise Kluyts, Sefako Makgatho Health Sciences University

MMed (Anaes), Department of Anaesthesiology, Sefako Makgatho Health Sciences University, South Africa

Veekash Gobin, Jawaharlal Nehru Hospital

Ministry of Health and Quality of Life, Jawaharlal Nehru Hospital (JNH), Rose Belle, Mauritius

Chaibou M Sani, National Hospital of Niamey

Anaesthesiologist and Chief of Department of Anesthesiology, Intensive Care and Emergency, National Hospital of Niamey, Republic of Niger

Eugene Zoumenou, Hôpital de la mère et de l'enfant

Faculté des Sciences de la Santé de Cotonou, Hôpital de la mère et de l'enfant, Lagune de Cotonou, Benin

Akinyinka O Omigbodun, University of Ibadan

FWACS, Professor of Obstetrics and Gynaecology, College of Medicine, University of Ibadan, Nigeria

Simbo D Amanor-Boadu, University College Hospital

Professor, Department of Anaesthesia, University College Hospital, Ibadan, Nigeria

Sanogo Zimogo Zié, CHU du POINT G

CHU du POINT G, Mali

Andrew Ndonga, Mater Hospital

FICS, General and Gastrosurgery, Mater Hospital, Kenya

Zipporah WW Ngumi, University of Nairobi

FFARCS, Inaugural Chair Department of Anaesthesia, University of Nairobi School of Medicine, Kenyaa

Dolly M Munlemvo, University Hospital of Kinshasa

Specialist in Anaesthesiology, University Hospital of Kinshasa, Democratic Republic of Congo

Charles Copley,, South Africa

Dawid van Straaten, Safe Surgery South Africa

Safe Surgery South Africa, South Africa

Patrice Forget, Vrije Universiteit Brussel

MD PhD, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Anesthesiology and Perioperative Medicine,  Brussels, Belgium

Rupert M Pearse, Queen Mary University of London

MD(Res), Professor of Intensive Care Medicine, Queen Mary University of London, United Kingdom

Bruce M Biccard, University of Cape Town

PhD, Professor and 2nd Chair, Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, South Africa






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