PURPOSE:

To determine whether family medical history as a risk factor for six common diseases is related to patients' perceptions of risk, worry, and control over getting these diseases.

METHODS:

We used data from the cluster-randomized, controlled Family Healthware Impact Trial (FHITr). At baseline, healthy primary care patients reported their perceptions about coronary heart disease, stroke, diabetes, and breast, ovarian, and colon cancers. Immediately afterward, intervention group participants used Family Healthware to record family medical history; this web-based tool stratified familial disease risks. Multivariate and multilevel regression analyses measured the association between familial risk and patient perceptions for each disease, controlling for personal health and demographics.

RESULTS:

For the 2330 participants who used Family Healthware immediately after providing baseline data, perceived risk and worry for each disease were strongly associated with family history risk, adjusting for personal risk factors. The magnitude of the effect of family history on perceived risk ranged from 0.35 standard deviation for ovarian cancer to 1.12 standard deviations for colon cancer. Family history was not related to perceived control over developing diseases. Risk perceptions seemed optimistically biased, with 48-79% of participants with increased familial risk for diseases reporting that they were at average risk or below.

CONCLUSIONS:

Participants' ratings of their risk for developing common diseases, before feedback on familial risk, parallels but is often lower than their calculated risk based on family history. Having a family history of a disease increases its salience and does not change one's perceived ability to prevent the disease.