Effect of Adding Systematic Family History Enquiry to Cardiovascular Disease Risk Assessment in Primary Care: A Matched-Pair, Cluster Randomized Trial

Study Questions:

What is the feasibility of systematically collecting family history of coronary heart disease in primary care, and the effect of incorporating these data into cardiovascular risk assessment?

Methods:

A matched-pair, cluster randomized, controlled trial was conducted in 24 family practices in the United Kingdom. A total of 748 persons, ages 30-65 years, with no previously diagnosed cardiovascular risk, were seen between July 2007 and March 2009. Participants in control practices had the usual Framingham-based cardiovascular risk assessment with and without use of existing family history information in their medical records. Participants in intervention practices also completed a questionnaire to systematically collect their family history. All participants were informed of their risk status. The primary outcome was the proportion of participants with high cardiovascular risk (10-year risk ≥20%). Other measures included questionnaire completion rate and anxiety score.

Results:

Ninety-eight percent of participants completed the family history questionnaire. The mean increase in proportion of participants classified as having high cardiovascular risk was 4.8 percentage points in the intervention practices, compared with 0.3 percentage point in control practices when family history from patient records was incorporated. The 4.5–percentage point difference between groups (95% confidence interval, 1.7-7.2 percentage points) remained significant after adjustment for participant and practice characteristics (p = 0.007). Anxiety scores were similar between groups.

Conclusions:

The authors concluded that systematically collecting family history increases the proportion of persons identified as having high cardiovascular risk for further targeted prevention, and seems to have little or no effect on anxiety.

Perspective:

The European Guidelines multiply the predicted 10-year cardiovascular disease risk by 1.5 if there is a family history of premature cardiovascular disease in a first-degree relative defined as male <55 years old and female <65 years old. Family history has been questioned as a legitimate risk factor because it may simply be a surrogate for lifestyle. In clinical practice in the modern era, that information can be obtained from reasonably educated patients. Whether the 1.5 multiplier is valid is not known, but the accuracy of family history of cardiovascular disease has increased in the past 40 years, which many believe has increased its usefulness for risk stratification in the individual.

Keywords: Great Britain, Life Style, Cardiovascular Diseases, Coronary Disease, Risk Factors, Confidence Intervals, Risk Assessment, Medical Records, Primary Health Care


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