The stroke offspring study: is parental stroke history of value in targeted risk factor screening?

This study aimed to compare the prevalence of stroke risk factors among people with a parental history of stroke to those in a control group of individuals, of similar age, gender and social class, with no parental stroke history. Parental stroke increases an individual's risk of stroke, but little is known of the potential value of using this information in targeted screening for primary prevention in general practice. We sent questionnaires to 300 randomly selected individuals aged 40-65 years, in each of 11 different general practices in Northern Ireland. Among 1061 responses received within six weeks, 332 reported a parental history of stroke (31.3%). We matched respondents with (cases) and without (controls) a parental history of stroke on characteristics of age, gender and socioeconomic status. Matched pairs were invited to attend a consultation at which their diet and exercise habits were assessed using validated questionnaires and height, weight, blood pressure and serum lipids and glucose were measured. Matched data were available for 199 case-control pairs (398 individuals). Mean systolic and diastolic blood pressures were significantly higher in cases than in paired controls (systolic 146.3 versus 140.6 mmHg (P < 0.01); diastolic 87.7 versus 85.0 mmHg (P = 0.014)). Cases consumed more alcohol than their paired controls (13.8 versus 10.1 U/week (P < 0.01)), but their measures of body mass index, lipids, diabetes, diet and exercise did not differ significantly. The results of this study suggest that screening offspring of patients with stroke in respect of blood pressure has potential value in identifying people likely to benefit from primary prevention, but do not support the adoption of a targeted screening strategy for other commonly cited stroke risk factors.