Background:

It is of utmost importance to identify hypertensive subjects in a country, in order to use efficiently public resources. The National Health Survey 2009-10 in Chile incorporated a third measurement of blood pressure (BP) during the home visit performed by a nurse, and a second day of measurement in a representative sub-sample.

Aim:

To study the effect of these two additional actions over both the average value of BP and the national prevalence of hypertension.

Material and Methods:

A third blood pressure measurement was carried out in 5,058 subjects, and it was measured in a second day in 930 individuals. The effect of these additional measurements on absolute blood pressure values and the prevalence of hypertension were assessed.

Results:

A small but statistically significant reduction in mean systolic pressure (0.52 mmHg) and the prevalence of hypertension (1%) was observed after the incorporation of the third blood pressure measurement. No effects in these figures were observed after the measurement performed on a second day.

Conclusions:

These findings should be considered when designing the new National Health Survey in Chile.