Research Paper Volume 12, Issue 24 pp 25005—25019

Sleep quality and risk of coronary heart disease - a prospective cohort study from the English longitudinal study of ageing

Figure 1. Study flow chart A total of 11050 participants from English longitudinal study of ageing cohort in wave 4 (2008-2009) were screened. After exclusion of participants with coronary heart disease at baseline, with missing data on sleep quality and sex, a total of 9570 participants were included for analysis. Participants were divided into three groups according to sleep quality and followed up over 8 years.