[Accuracy of anamnestic data in the definition of the familial history of hypertension]

Positive family history for hypertension (H) in adolescence is a major predictor of development of H in adult life. In epidemiologic studies, family history for H has usually been recorded anamnestically. In the present study, feasibility of the anamnestic data referred by a population of 1142 high school students has been evaluated through the measurement of blood pressure (BP) of their parents. 1519 out of the 2139 eligible (adhesion rate 71.0%) actually attended the visit. Parents were considered to be hypertensive when they were on antihypertensive treatment or when a diastolic BP ≥ 95 mmHg (average of three readings) was found and confirmed one year later. Definition of the family history for H was possible in the 46.6% of the adolescents on the basis of the anamnestic data, in 64.6% in the basis of the objective ascertainment. The anamnestic data led to an overestimation of positive family history (16.7% vs 9.3% ascertained). Agreement between anamnestic and ascertained family history was very poor (K=0.37). Particularly, 7.8% out of those claimed both the parents had normal BP values, had at least one hypertensive parent; on the contrary, in more than the half of sons (58.9%) with anamnestic positive family history, the objectively recorded BP of parents was normal. The objective definition of family history for H seems to be essential, especially in those studies which include among their goals the evaluation of a positive family history as risk factor for hypertension.