Why should population attributable fractions be periodically recalculated? An example from cardiovascular risk estimation in southern Europe.

Abstract Objective To determine the effect of age and study period on coronary heart disease (CHD) risk attributable to cardiovascular risk factors. Methods A cohort of cardiovascular disease (CVD)-free randomly participants from Girona (Spain) aged 35–74 years recruited in 1995 and 2000 and followed for an average of 6.9 years. A survey conducted in the same area in 2005 was also used for the analysis. Smoking, hypertension, diabetes, sedentary lifestyle, obesity, total cholesterol ≥ 240 mg/dl, low-density lipoprotein (LDL) cholesterol ≥ 160 mg/dl, and high-density lipoprotein cholesterol Results LDL cholesterol had the highest potential for CHD prevention between 35 and 74 years [42% (95% Confidence Interval: 23,58)]. The age-stratified analysis showed that the population attributable risk (PAF) for smoking was 64% (30,80) in subjects Conclusion Overall, LDL cholesterol levels had the highest potential for CHD prevention. Periodic PAF recalculation in different age groups may be required to adequately monitor population trends.