As part of a large survey, a group of 45-54 year old males from industrial and professional group in the West of Scotland had their serum cholesterol levels measured and were followed up over a 5-year period. Records of deaths, along with causes of death, were obtained for the group from the Registrar General. n

After 5 years of follow-up, 25 men died from CHD. summary statistics are given below

CHD group: n=25; mean=6.51; SD=1.15 (or median=6.5; quartiles=5.6, 7.4; extremes=4.4, 8.8) Alive group: n=2475; mean=5.89; SD=0.99 (or median=5.9; quartiles=5.2, 6.6; extremes=3.1, 8.9)

Is there any evidence that serum cholesterol is a risk factor for CHD?