Systematic family history data identifies more patients at CV risk

22 February 2012

MedWire News: Systematically collecting a family history from primary care patients significantly increases the number identified as being at high cardiovascular (CV) risk, say UK researchers.

“Our findings highlight the promising role that greater use of systematic family history collection could play in a targeted strategy in primary care,” write Nadeem Qureshi (University of Nottingham) and co-authors in the Annals of Internal Medicine.

They conducted a cluster randomized controlled trial of 748 individuals aged between 30 and 65 years who had no previously diagnosed CV risk, and were seen at one of 12 family practices in the UK between July 2007 and March 2009.

All patients were randomly allocated to undergo either standard CV risk assessment (control group) or additional detailed collection of family history data (intervention group).

Patients in the intervention group completed a questionnaire that covered personal medical history, details of coronary heart disease (CHD) in parents and grandparents, and family size (number of siblings, offspring, uncles, and aunts). The participants completed further sections if they could remember any relatives listed in the family size section who had CHD or died.

Electronic health records for all patients at each practice were reviewed to identify available data on family history of premature CHD and to obtain anonymized data on other CV risk factors, investigations, medication, and newly diagnosed CHD.

Framingham CV risk scores were calculated for all patients. Those who had a CV disease risk of 20% or greater over the next 10 years were offered an appointment to see their family physician or office nurse 2 weeks after being notified of their results. During this consultation, the increased risk was explained and lifestyle advice was offered. For intervention patients, the effect of a family history of premature CHD on CV risk was also discussed.

The results revealed that when using systematically collected family history data, the percentage of participants in the intervention group classified by the researchers as being at high CV risk (10-year risk ≥20%) increased by 5.1 percentage points compared with just a 0.5-percentage point increase among participants in the control group when family history from electronic health records was incorporated.

The number of participants classified as high risk in the intervention group increased by 40.8% after family history from the questionnaire was incorporated, compared with a 5.6% increase in the control group.

Across the intervention practices (traditional vs systematic), the percentage of participants at high CV risk increased by a mean of 4.8 percentage points, compared with a mean increase of 0.3 percentage points in the control practices when family history from electronic health records was incorporated. Therefore, the mean difference between the study groups was 4.5 percentage points when family history from the control group was incorporated, note the authors.

After adjusting for participant- and practice-level variables, the between-group difference remained significant (p=0.007).

Qureshi and team conclude that the low-cost approach, and high response and completion rates, suggest that family history data collection by self-completed questionnaires is “feasible.”

In a related commentary, Alfred Berg (University of Washington, Seattle, USA) confessed that he was initially skeptical about the use of genetic data collection in primary care practice and said that the strength of the data in the current study proved him wrong.

He noted that in a practice of 10,000 adult patients, the systematic collection of family history using “the lowest-tech genetic test imaginable” would identify 400–500 more patients at high CV risk.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012

Ann Intern Med 2012; 156: 253–262, 315–316