In the 25 years between 1981 and 2006 mortality rates from coronary heart disease (CHD) in Iceland decreased by a remarkable 80 percent in men and women aged between 25 and 74 years. How could such a huge decline be explained? To find out, researchers applied a validated CHD analysis model to official Icelandic death statistics, national quality registers, published trials and meta-analyses, clinical audits and a series of national population surveys.
Results of the study show that approximately three-quarters of the mortality decrease in Iceland was attributable to reductions in risk factors throughout the general population. These were principally (36 percent) in the reduction of cholesterol levels, smoking (20 percent) and systolic blood pressure (26 percent) and in the greater uptake of physical activity (five percent).
In addition, approximately one quarter of the decrease in CHD deaths in Iceland was attributable to treatment in individuals: seven percent to secondary prevention (for instance medical treatment or surgery following a heart attack or other CHD event), six percent to treatments for heart failure, five percent to initial treatments of acute coronary syndrome, and one percent to treating hypertension.
However, not all risk factor profiles improved. Negative trends were found in the prevalence of diabetes, increasing by five percent, and in obesity, increasing by four percent.
Comparable results have also been found when the model was applied in other countries. For example, a fall in CHD deaths in England and Wales between 1981 and 2000 was explained by both an improvement in risk factors in the general population (71 percent) and treatments in individuals (41 percent) – though offset by worsening population trends in body weight, exercise and diabetes. A similar pattern was found in the USA.
MEDICA.de; Source: European Society of Cardiology