Cognitive and behavioural effects of genetic testing for thrombophilia.

Very few studies have examined the impact of genetic testing for thrombophilia on health behaviours, perceptions of control over risk factors for venous thromboembolism, or health services utilization. Through a postal questionnaire we compared first degree relatives with thrombophilia (carriers) most of whom had received counseling, to those without (non-carriers) with respect to: (a) perceived causes of venous thromboembolism; (b) perceived control; (c) health behaviour changes; and (d) use of health care services. 44/51 for carriers and 26/47 for non-carriers completed questionnaires. Carriers were more likely to believe their risk of venous thromboembolism 'is a little higher' or 'much higher' than average (p < 0.001) but some continued to believe their risk 'is the same as' or 'lower than' average. 16%-32% of carriers did not recognize major risk factors. Stress, worry, or depression, negative attitude, and over-exertion were over-interpreted as risks. 37.2% did not appreciate that thrombophilia increases risk. Behaviour changes were uncommon. There is a need for research on education and strategies to improve knowledge in thrombophilia carriers.