Ethnic density distributions (%) by Middle Super Output Area mapped across south and east London for general practitioner-registered populations: a) Bangladeshi, b) Caribbean, c) White and d) African. © OpenStreetMap contributors. Ethnic density distributions (%) by Middle Super Output Area mapped across south and east London for general practitioner-registered populations: a) Bangladeshi, b) Caribbean, c) White and d) African. © OpenStreetMap contributors. OpenStreetMap is open data, licensed under the Open Data Commons Open Database License by the OpenStreetMap Foundation. Rohini Mathur et al. ERJ Open Res 2017;3:00130-2016 ©2017 by European Respiratory Society