Mortality from coronary heart disease (CHD) has been halved in Great Britain and other industrialized countries since the 1980s. To determine the extent to which primary and secondary prevention have contributed to decreased CHD mortality in England and Wales, researchers used the IMPACT CHD mortality model to synthesize data from national surveys, official statistics, clinical audits, controlled trials, and meta-analyses.
From 1981 through 2000, age-specific CHD mortality fell by 62% in men and 45% in women and resulted in about 68,200 fewer deaths in 2000 than in 1981. During this period, smoking prevalence fell by 35% and resulted in about 30,000 fewer deaths (5000 in people with known CHD and 25,000 in people without CHD). Population cholesterol levels fell by 4.2%, resulting in about 7900 fewer deaths. Of the 5770 fewer deaths attributed to dietary changes, about 1200 were in CHD patients and about 4500 in people without CHD. Statin treatment was estimated to have prevented 1990 deaths in people with CHD and 145 deaths in people without CHD. Mean population diastolic blood pressure fell by 7.7%, resulting in 7700 fewer deaths (about 500 in CHD patients, 5300 in healthy people, and 1900 in hypertensive people). Overall, 81% of averted deaths were in people without CHD and 19% were in those with known CHD.
The value of these results is that they integrate several data sources and indicate that primary prevention contributed more to the decline in CHD mortality than did secondary prevention. The results do not address questions about cost-effectiveness.
Reference:
Unal B et al. Modelling the decline in coronary heart disease deaths in England and Wales, 1981–2000: Comparing contributions from primary prevention and secondary prevention. BMJ 2005 Sep 17; 331:614-7.