Framingham Risk Prediction Equations for Incidence of Cardiovascular Disease Using Detailed Measures for Smoking

Abstract

Current prediction models for risk of cardiovascular disease (CVD) incidence incorporate smoking as a dichotomous yes/no measure. However, the risk of CVD associated with smoking also varies with the intensity and duration of smoking and there is a strong association between time since quitting and the risk of disease onset. This study aims to develop improved risk prediction equations for CVD incidence incorporating intensity and duration of smoking and time since quitting.The risk of developing a first CVD event was evaluated using a Cox's model for participants in the Framingham offspring cohort who attended the fourth examination between the ages of 30 and 74 years and were free of CVD (n=3751). The full models based on the smoking variables and other risk factors, and reduced models based on the smoking variables and non-laboratory risk factors demonstrated good discrimination, calibration and global fit. The incorporation of both time since quitting among past smokers and packyears among current smokers resulted in better predictive performance as compared to a dichotomous current/non-smoker measure and a current/quitter/never smoker measure. Compared to never smokers, the risk of CVD incidence increased with pack-years. Risk among those quitting more than five years prior to the baseline exam and within five years prior to the baseline exam were similar and twice as high as that of never smokers. A CVD risk equation incorporating the effects of pack-years and time since quitting provides an improved tool to quantify risk and guide preventive care.

Association of Family History With Cardiovascular Disease in Hypertensive Individuals in a Multiethnic Population

“…Individuals were considered smokers if they reported that they were currently smoking or when they had stopped smoking less than 5 years ago …”

Biological variation of established and novel biomarkers for atherosclerosis: Results from a prospective, parallel-group cohort study

“…Exclusion criteria were missing informed consent, severe renal failure defined as estimated glomerular filtration rate (GFR) ≤ 30 ml/min according to the MDRD formula [25], severe liver dysfunction (defined as chronic hepatic disease, e.g., cirrhosis, or previously documented biochemical evidence of significant hepatic derangement) [26], and atherothrombotic events -namely acute coronary syndromes, stroke, transient ischemic attack or any cardiovascular intervention within 4 weeks prior to study enrollment. Additional exclusion criteria for the control group were excessive smoking history (N 10 pack-years) [27], diabetes mellitus (fasting plasma glucose ≥ 7 mmol/l, or hemoglobin A1 c ≥ 6.5%), hypertension (ambulatory blood pressure N 140/90 mm Hg, or antihypertensive medication), hyperlipidemia (LDL-cholesterol ≥ 4.1 mmol/l) or history of venous thromboembolism.…”

The Effects of Two Exercise Modalities on Novel Cardiovascular Risk Factors in Overweight Women with Type 2 Diabetes: a Randomized Controlled Trial

“…This equation considers gender, age, systolic blood pressure, smoking status, total cholesterol, HDL-C, and diabetes mellitus status to calculate the percentage likelihood of a coronary disease over a 10year period [37].…”