Change of sleep duration (in hours) and sleep efficiency (in %) (95%-confidence interval (CI)) for various exposure measures from the nested sleep study.

a)<p>adjusted for: age, percent fulltime equivalent, bedtime (derived from diary) (all linear), sex, body mass index (<25, ≥25), smoking status, weekday (weekend vs. workday), presence of a bed partner, alcohol intake within 4 hours before going to bed (diary), physical activity during the day (diary), sleeping during the day (diary) (all binary), and educational level (3 categories).</p>b)<p>The division into the exposure categories was done on the individual level.