J. Mar et al., AMBULATORY BLOOD-PRESSURE MONITORING AND DIAGNOSTIC ERRORS IN HYPERTENSION - A BAYESIAN-APPROACH, Medical decision making, 18(4), 1998, pp. 429-435
Citations number
37
Categorie Soggetti
Medical Informatics","Health Care Sciences & Services
Random variability of blood pressure complicates the diagnosis and sub
sequent treatment of hypertension. To evaluate the importance of the n
umber of blood pressure measurements in the correct diagnosis and cont
rol of hypertension, the authors used a Bayesian model to estimate the
true average blood pressure of a group of newly diagnosed hypertensiv
es, then calculated the diagnostic error that would result from monito
ring methods using 24 daytime measurements or from using only three ra
ndom monitoring measurements. The study population consisted of 129 in
dividuals with newly diagnosed mild hypertension according to standard
criteria, who were also evaluated with an ambulatory blood pressure m
onitor. In true normotensives (daytime diastolic blood pressure <90 mm
Hg), the negative predictive value with three measurements was 0.92,
and it rose to 0.96 with monitoring methods. In mild hypertensives (90
-104 mm Hg), the positive predictive value was 0.64 with three measure
ments and 0.84 with monitoring methods, thus reducing the rate of fals
e mild hypertensives from 35% to 15%. Finally, in patients with modera
te or severe hypertension (>104 mm Hg), the positive predictive value
improved from 0.26 with three readings to 0.61 with monitoring methods
. Similar results were observed with daytime systolic pressure measure
ments. As the number of measurements increased, the diagnostic error d
ue to the random variability of blood pressure became progressively sm
aller. In cases of hypertension, the large improvement in predictive v
alues may justify using monitoring methods to confirm standard diagnos
is.