A clinical decision support tool is an interactive software application designed to assist patients and their health professionals with decision making tasks. This clinical decision support tool for the Primary Prevention of Cardiovascular Disease provides an individualized estimate of a person's chance of having a cardiovascular event (developing coronary heart disease or having a stroke) over a ten year period of time. It also provides recommendations to reduce your risk of having a cardiovascular event based on current Canadian guidelines for the Primary Prevention of Cardiovascular Disease. And finally, it provides an estimate of the potential benefits of various risk reduction interventions (medications and lifestyle changes). It is only valid for people who have never had a cardiovascular event.
This tool is designed for adults aged 35 to 75 years who do not have heart disease, stroke, or diabetes. It is designed to help patients and their doctors decide what strategy of reducing their risk of having a heart attack or stroke is best for them.
To start using this tool, you must provide YOUR CURRENT RISK FACTORS:
YOUR CURRENT RISK ESTIMATE displays your risk of developing coronary heart disease and stroke over the next 10 years both numerically and graphically (outcomes for 100 people with your same risk factors are displayed, as this format seems to be one of the better ways to visually present risks; refer to the legend for help interpreting the graph). Risk estimates are rounded to two significant digits, although there is likely an error associated with these estimates of at least +/- 5-10%.
Individualized RECOMMENDATIONS from current Canadian guidelines for the primary prevention of cardiovascular disease based on your particular risk factors are provided. These recommendations include suggestions for lifestyle interventions as well as possible suggestions for medications.
Select an intervention from the list of INTERVENTIONS TO MODIFY TOUR RISK. YOUR MODIFIED RISK ESTIMATE will then be displayed. Compare this new 10-year risk estimate to YOUR CURRENT RISK ESTIMATE to see how the selected intervention might benefit you in terms of reducing your risk. Risk reduction estimates are also displayed in terms of "Numbers Needed to Treat", that is, how many people would need to be treated for ten years for one person to benefit in terms of prevented coronary heart disease or stroke.
Checking the box for 'Show uncertainty (95% confidence intervals) of risk reduction data' will change both the numerical modified risk estimates and the graphical representation to display the 95% confidence interval of the clinical trial data.
Checking the box for 'Display risk of adverse events' will display the clinical trial data for adverse events related to the selected intervention.
Note that most clinical trial data comes from trial lasting less than ten years, so some caution should be exercised in interpreting these estimates.
YOUR CURRENT RISK ESTIMATE is derived using an algorithm from the Framingham Heart Study that is modified for family history using data from the Framingham Offspring Study. Clicking on the reference  (either here or in the calculator) will display a summary of these studies as well the literature references for them. YOUR MODIFIED RISK ESTIMATE is derived is derived by applying relative risk reduction outcomes from clinical trials to your initial risk estimate. Clinic trial data is mainly taken from systematic reviews. Clicking on the reference  (in the calculator) will display a summary of the applicable evidence as well the literature reference for it.
The RECOMMENDATIONS are a summary of the recommendations from 5 separate current Canadian guidelines for the primary prevention of cardiovascular disease. Clicking on the references , , , , or  (either here or in the calculator) will display the applicable guideline as well as the literature reference for it.
Note that the guidelines are not always in agreement on whether a particular risk reduction intervention is recommended.
Comments or questions?
Please provide feedback and suggestions to Dr. Anton Rabien at AntonRabien@SookeFamilyDocs.com.
Tobe SW, et al., "Harmonization of guidelines for the prevention and treatment of cardiovascular disease: the C-CHANGE Initiative," CMAJ, vol. 183, no. 15, pp. 1135-1150., Oct 2011.
Anderson TJ, et al., "2012 update of the Canadian Cardiovascular Society guidelines for the diagnosis and treatment of dyslipidemia for the prevention of cardiovascular disease in the adult," The Canadian journal of cardiology, vol. 29, pp. 151-167, 2013.
Hackman DG, et al., "The 2013 Canadian hypertension education program (CHEP) Recommendations for Blood Pressure Measurement, Diagnosis, Assessment of risk, prevention, and treatment of hypertension," The Canadian journal of cardiology, vol. 29, pp. 528-542, May 2013.
Chatterjee A, et al., "Managing cardiometabolic risk in primary care – summary of the 2011 consensus statement," Can Fam Physician, vol. 58, no. 4, p. 389–393, April 2012.
Bell AD, et al., "The use of antiplatelet therapy in the outpatient setting: Canadian cardiovascular society guidelines," The Canadian journal of cardiology, vol. 27, no. 3, pp. 1-59, May 2011.
This version of the Framingham risk algorithm was derived using data from 8,491 Framingham heart study participants who were free of CVD (mean age 49 years; age range 30 to 74 years; percent male/female 47/53; mean baseline systolic BP 130mmHg; mean baseline total cholesterol 5.5mmol/L; mean baseline HDL 1.2mmol/L ). Over 12 years of follow-up, 18% of men and 10% of women developed a first CVD event. The risk factors evaluated predicted CVD risk (multivariable-adjusted P < 0.0001). The algorithm demonstrated good discrimination (C statistic, 0.763 [men] and 0.793 [women]) and calibration.
Reference: D'Agostino RB, Vasan RS, Pencina MJ, Wolf PA, Cobain M, Massaro JM, Kannel WB. General Cardiovascular Risk Profile for Use in Primary Care: The Framingham Heart Study. Circulation. 2008;117:743-753.
Adjustment of Baseline Risk Estimate to Account for Family History
The Framingham Offspring Study followed 2,302 offspring of participants in the original Framingham Heart Study (mean age 44 years; percent male/female 49/51; mean baseline systolic BP 123; mean baseline total cholesterol 5.6 mmol/L, mean baseline HDL 1.3 mmol/L). Over 8 years of follow-up, 14.5% of men and 6.7% of women experienced a first CVD event. The adjusted odds ratio of developing CVD with a history of early CVD in one or both parents was 1.7 for women and 2.0 for men.
Reference: Lloyd-Jones DM, Nam BH, D'Agostino RB, Levy D, Murabito JM, Wang TJ, Wilson PWF and O'Donnell CJ, "Parental cardiovascular disease as a risk factor for cardiovascular disease in middle-aged adults: A prospective study of parents and offspring," JAMA, vol. 291, no. 18, pp. 2204-2211, 2004.