1. Use of the Robson classification to assess caesarean section trends in 21 countries: a secondary analysis of two WHO multicountry surveys 
Dr Joshua P Vogel, MBBS, Ana Pilar Betrán, PhD, Nadia Vindevoghel, MD, João Paulo Souza, PhD, Maria Regina Torloni, PhD, Prof Jun Zhang, PhD, Özge Tunçalp, PhD, Rintaro Mori, MD, Naho Morisaki, PhD, Eduardo Ortiz-Panozo, MD, Bernardo Hernandez, DSc, Ricardo Pérez-Cuevas, DrSc, Zahida Qureshi, MD, A Metin Gülmezoglu, PhD, Marleen Temmerman, PhD 
The Lancet Global Health 
Volume 3, Issue 5, Pages e260-e270 (May 2015)
DOI: /S X(15)70094-X
Copyright © 2015 World Health Organization Terms and Conditions

2. Figure 1 Study flowchart
The Lancet Global Health 2015 3, e260-e270DOI: ( /S X(15)70094-X)
Copyright © 2015 World Health Organization Terms and Conditions

3. Figure 2 Robson groups in WHOGS and WHOMCS, stratified by HDI group
(A) Size of obstetric population in each Robson group. (B) Caesarean section rate in each Robson group. (C) Absolute contribution of each Robson group to the overall caesarean section rate. (D) Change in absolute contribution of each Robson group to the overall caesarean section rate. Only Robson groups 1–5 are presented; groups 6–10 account for only 15% of the obstetric population and 20% of the relative contribution to the overall caesarean section rate. HDI=Human Development Index. WHOGS=WHO Global Survey. WHOMCS=WHO Multi-Country Survey.
The Lancet Global Health 2015 3, e260-e270DOI: ( /S X(15)70094-X)
Copyright © 2015 World Health Organization Terms and Conditions