Studies of any design that evaluated the psychological effects of testing for thrombophilia in at least 15 participants were eligible for inclusion. Secondary outcomes included satisfaction levels and uptake of behavioural change post testing.
All but one of the included studies tested for factor V Leiden either alone or in combination with up to six other thrombophilic defects; one study tested for protein C deficiency. Overall of the included studies, just over a third (38 per cent) of participants were apparently healthy with no history of venous thromboembolism (VTE), one third (33 per cent) were asymptomatic relatives of patients who had had a VTE and 23 per cent had experienced a VTE; no such information was provided about other participants. Studies assessed outcomes using qualitative semi-structured interviews and validated and unvalidated questionnaires. The duration of follow-up ranged from 20 days to 10 years or more.
Two reviewers independently selected studies.