Of the 9,238,453 men and women invited to join UK Biobank, 503,317 (5.45%) consented and were recruited between 2006 and 2010. Overall, the participation rate was higher in women (participation rates were 6.4% and 5.1% in women and men, respectively) (Figure 1A), in older age groups (9% in those aged ≥60 years and 3% in those aged 40–44 years) (Figure 1B), and in less socioeconomically deprived areas (8.3% among persons from the least deprived areas and 3.1% among persons from the most deprived areas) (Figure 1C). Participation rates showed regional differences, being highest in South West England (9.6%) and East Scotland (8.2%) and lowest in West Scotland (4.3%), London, the West Midlands, and North West England (all 4.7%) (Figure 1D; also see Web Table 2 for further details).
