Probability of stroke: a risk profile from the Framingham Study.

Abstract

A health risk appraisal function has been developed for the prediction of stroke using the Framingham Study cohort. The stroke risk factors included in the profile are age, systolic blood pressure, the use of antihypertensive therapy, diabetes mellitus, cigarette smoking, prior cardiovascular disease (coronary heart disease, cardiac failure, or intermittent claudication), atrial fibrillation, and left ventricular hypertrophy by electrocardiogram. Based on 472 stroke events occurring during 10 years' follow-up from biennial examinations 9 and 14, stroke probabilities were computed using the Cox proportional hazards model for each sex based on a point system. On the basis of the risk factors in the profile, which can be readily determined on routine physical examination in a physician's office, stroke risk can be estimated. An individual's risk can be related to the average risk of stroke for persons of the same age and sex. The information that one's risk of stroke is several times higher than average may provide the impetus for risk factor modification. It may also help to identify persons at substantially increased stroke risk resulting from borderline levels of multiple risk factors such as those with mild or borderline hypertension and facilitate multifactorial risk factor modification. (Stroke 1991;22:312-318) S troke is the third leading cause of death in the United States and is a major source of disability in persons older than age 60 years. In the face of an elderly population of increasing size, stroke is likely to be responsible for even greater disability and death. Epidemiologic study has identified key risk factors for stroke and has provided an estimate of the relative impact of these factors. Using data collected over 36 years of follow-up in the general population sample at Framingham, Mass., a stroke risk profile or health risk appraisal function has been developed. This profile contains a number of ingredients not available at the time of the previous stroke risk handbook, which was based on 16 years of follow-up. 1 The inclusion of previously diagnosed cardiovascular disease (coronary heart disease Received October 15, 1990; accepted November 27, 1990. [includes history of myocardial infarction, angina pectoris, and coronary insufficiency], cardiac failure, and intermittent claudication), atrial fibrillation, and left ventricular hypertrophy by electrocardiogram as ingredients in the profile has improved the efficiency of the risk prediction and gives a more realistic assessment of the importance of the stroke risk factors. Key to the usefulness of determining the likelihood of stroke by means of a risk profile is evidence that modification of several potent risk factors will reduce stroke probability. Epidemiologic study and clinical trial results have shown that reduction of elevated blood pressure and cessation of cigarette smoking can reduce stroke incidence. Warfarin (and perhaps aspirin) therapy in persons with atrial fibrillation, reversal of left ventricular hypertrophy by electroca...

Stroke Epidemiology: Advancing Our Understanding of Disease Mechanism and Therapy

“…Longitudinal studies have identified several characteristics/conditions that boost a person's risk for primary or recurrent stroke [4,19]. These risk factors are viewed as nonmodifiable or modifiable and generally apply to primary and recurrent stroke.…”

“…Coronary Artery Disease Individuals with a presence of coronary artery disease have double the risk of stroke compared to patients without coronary artery disease [19]. The attributable risk of stroke due to coronary artery disease is approximately 12%.…”

The Framingham and UK Prospective Diabetes Study (UKPDS) risk equations do not reliably estimate the probability of cardiovascular events in a large ethnically diverse sample of patients with diabetes: the Action in Diabetes and Vascular Disease: Preterax and Diamicron-MR Controlled Evaluation (ADVANCE) Study

“…adjusting the models by replacing average values of predictors and event rates in the original population by those in the target population (i.e. the ADVANCE Study), could improve performance of the risk models [21][22][23][24]. Recalibration was restricted to the outcomes major CVD, major CHD and stroke.…”

“…Recalibration was restricted to the outcomes major CVD, major CHD and stroke. The recalibration method proposed by the Framingham investigators was used to recalibrate the Framingham D'Agostino equations [21,22]; and the method proposed by van Houwelingen [24] was used for the Framingham Anderson and UKPDS equations, which are both parametric models. The UKPDS equations were originally modelled at the mean levels of continuous predictors (age, systolic BP, HbA 1c and total cholesterol:HDL-cholesterol ratio) specific to the UKPDS population [9,11].…”

Field Synopsis of the Role of Sex in Stroke Prediction Models

“…Sex was included in only 6% (1/16) of models predicting any outcome among patients with hemorrhagic stroke, as compared to 24% (6/25) of such models among ischemic stroke patients. Study‐ and model‐level characteristics of the 30 stroke‐related CPMs that included sex are presented in Table 2 25, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54…”