Non-response bias in the analysis of the association between mental health and the urban environment: a cross-sectional study in Brussels, Belgium, Guyot, Madeleine, Pelgrims Ingrid, Aerts Raf, Keune Hans, Remmen Roy, De Clercq Eva M., Thomas Isabelle, and Vanwambeke, Sophie O. , Archives of Public Health, Jan-12-2023, Volume 81, Issue 1, (2023)