title: 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 > or = 240 mg/dl, low-density lipoprotein (LDL) cholesterol > or = 160 mg/dl, and high-density lipoprotein cholesterol <40 mg/dl were the risk factors considered. The composite end-point included myocardial infarction, angina pectoris, and CHD death.
  
  
  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 < 55 years; for those > or = 55 years, the PAF for hypertension was 34% (1,61). The decrease observed between 1995 and 2005 in the population's mean LDL cholesterol level reduced that PAF in all age groups.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Epidemiology and Cardiovascular Genetics, Program of Research on Inflammatory and Cardiovascular Disorders, Institut Municipal d'Investigació Mèdica, 08003 Barcelona, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Grau
authors.forename: Isaac
authors.initials: I
authors.lastname: Subirana
authors.forename: Roberto
authors.initials: R
authors.lastname: Elosua
authors.forename: Montserrat
authors.initials: M
authors.lastname: Fitó
authors.forename: Maria-Isabel
authors.initials: MI
authors.lastname: Covas
authors.forename: Joan
authors.initials: J
authors.lastname: Sala
authors.forename: Rafael
authors.initials: R
authors.lastname: Masiá
authors.forename: Rafel
authors.initials: R
authors.lastname: Ramos
authors.forename: Pascual
authors.initials: P
authors.lastname: Solanas
authors.forename: Ferran
authors.initials: F
authors.lastname: Cordon
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Nieto
authors.forename: Jaume
authors.initials: J
authors.lastname: Marrugat
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D003327:Coronary Disease / Q000453:epidemiology / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology* / Q000517:prevention & control; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000517:prevention & control*; D009765:Obesity / Q000453:epidemiology; D016491:Peripheral Vascular Diseases / Q000453:epidemiology / Q000517:prevention & control; D015995:Prevalence; D012307:Risk Factors; D057185:Sedentary Behavior; D012907:Smoking / Q000453:epidemiology; D013030:Spain / Q000453:epidemiology