Lay constructions of a family history of heart disease: potential for misunderstandings in the clinical encounter?

BACKGROUND: Family history is recognised as a risk factor for coronary heart disease (CHD) by epidemiologists, health professionals, and the public, and could act either as a spur or barrier to changing health behaviour. However, there has been no systematic investigation of which factors affect whether people regard themselves as having a family history of CHDor not.
METHODS: We used purposive sampling to select 61 men and women who were middle class or working class from a large cross-sectional survey. Half the respondents had indicated in this previous survey that they had heart disease in their family. The range of understanding of the meaning of having a family history was explored in detailed qualitative semistructured interviews.
FINDINGS: Perception of a family history of heart disease depended on knowledge of the health of family members, the number and closeness of relatives with heart conditions, the age of affected relatives, and the respondent's sex and social class. Men, particularly working-class men, required a greater number of close relatives to be affected to perceive that they had a family history. Even when respondents judged that heart disease ran in their family, they did not always perceive themselves as at increased risk because they felt different in crucial ways from affected relatives.
INTERPRETATION: The factors that people and epidemiologists judge as relevant to establish presence of a family history can differ. We suggest that these differences could lead to misunderstandings between doctor and patient, which could undermine advice on CHD risks and associated behavioural changes.