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“In cities, it’s not far, but it takes long”: comparing estimated and replicated travel times to reach life-saving obstetric care in Lagos, Nigeria
  1. Aduragbemi Banke-Thomas1,2,
  2. Kerry L M Wong3,
  3. Francis Ifeanyi Ayomoh4,
  4. Rokibat Olabisi Giwa-Ayedun5,
  5. Lenka Benova6
  1. 1LSE Health, London School of Economics and Political Science, London, UK
  2. 2Centre for Reproductive Health Research and Innovation, Lagos State University College of Medicine, Lagos, Nigeria
  3. 3Infectious Disease and Epidemiology, London School of Hygiene & Tropical Medicine Faculty of Epidemiology and Population Health, London, UK
  4. 4Department of Health Planning, Research and Statistics, Federal Ministry of Health, Abuja, Nigeria
  5. 5Maternal and Child Centre, Ifako Ijaiye General Hospital, Lagos, Nigeria
  6. 6Department of Public Health, Institute of Tropical Medicine, Antwerpen, Belgium
  1. Correspondence to Dr Aduragbemi Banke-Thomas; a.banke-thomas{at}


Background Travel time to comprehensive emergency obstetric care (CEmOC) facilities in low-resource settings is commonly estimated using modelling approaches. Our objective was to derive and compare estimates of travel time to reach CEmOC in an African megacity using models and web-based platforms against actual replication of travel.

Methods We extracted data from patient files of all 732 pregnant women who presented in emergency in the four publicly owned tertiary CEmOC facilities in Lagos, Nigeria, between August 2018 and August 2019. For a systematically selected subsample of 385, we estimated travel time from their homes to the facility using the cost-friction surface approach, Open Source Routing Machine (OSRM) and Google Maps, and compared them to travel time by two independent drivers replicating women’s journeys. We estimated the percentage of women who reached the facilities within 60 and 120 min.

Results The median travel time for 385 women from the cost-friction surface approach, OSRM and Google Maps was 5, 11 and 40 min, respectively. The median actual drive time was 50–52 min. The mean errors were >45 min for the cost-friction surface approach and OSRM, and 14 min for Google Maps. The smallest differences between replicated and estimated travel times were seen for night-time journeys at weekends; largest errors were found for night-time journeys at weekdays and journeys above 120 min. Modelled estimates indicated that all participants were within 60 min of the destination CEmOC facility, yet journey replication showed that only 57% were, and 92% were within 120 min.

Conclusions Existing modelling methods underestimate actual travel time in low-resource megacities. Significant gaps in geographical access to life-saving health services like CEmOC must be urgently addressed, including in urban areas. Leveraging tools that generate ‘closer-to-reality’ estimates will be vital for service planning if universal health coverage targets are to be realised by 2030.

  • geographic information systems
  • maternal health
  • obstetrics
  • other study design

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  • Handling editor Seye Abimbola

  • Twitter @abankethomas, @kerrylmwong, @lenkabenova

  • Contributors ABT conceived the study. ABT, KLMW and LB designed the study. ABT, FIA and ROGA led the data collection. ABT and KLMW did the statistical analyses. ABT and KLMW wrote the first draft of the article. All authors critically reviewed the article and approved the final draft.

  • Funding This research was funded by grant provided by AXA Research Fund.

  • Map disclaimer The depiction of boundaries on this map does not imply the expression of any opinion whatsoever on the part of BMJ (or any member of its group) concerning the legal status of any country, territory, jurisdiction or area or of its authorities. This map is provided without any warranty of any kind, either express or implied.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Patient consent for publication Not required.

  • Ethics approval We obtained ethical approval from the Research and Ethics Committees of Lagos State University Teaching Hospital (LASUTH) (LREC/06/10/1226) and Lagos University Teaching Hospital (LUTH) (ADM/DCST/HREC/APP/2880). Social approval was received from the Lagos State Government (LSHSC/2222/VOLII/107). As this study was based on patient records, we minimised the risk of patient identification by not collecting data on patient names and specific street numbers. In mapping, we selected midpoint of streets of origin to ensure that participants cannot be identified.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.