Figure 5. The univariate association between sleep apnea and incidence of cardiovascular disease.

The vertical axis indicates the cumulative number of hospitalizations or deaths from coronary heart disease was not statistically higher across the 20 years (horizontal axis) in those people with moderate-severe sleep apnea (respiratory disturbance index [RDI] ≥ 15/h: the green line) compared to those with mild sleep apnea (RDI 5-14: the red line) or those with no sleep apnea (RDI < 5: the blue line). The numbers just above the horizontal axis indicate the numbers of people being observed at each 2-year time point in each of the sleep apnea groups. The shaded areas around the lines represent the 95% confidence intervals.