Læknablaðið - 15.05.1996, Blaðsíða 15

LÆKNABLAÐIÐ 1996; 82
371
Blóðþrýstingur, hvítir sloppar
og mælistaðir
Samanburður á blóðþrýstingsmælingum karla á
heilbrigðisstofnunum, vinnustöðum og í heimahúsum
Jóhann Ág. Sigurðsson1), Bjöm Aðalsteinsson21, Þórður Harðarson31, Árni Kristinsson3,4’
Sigurðsson JÁ, Aðalstcinsson B, Harðarson Þ,
Kristinsson Á
Blood prcssure at the clinic, work and homc. Are
there white coats at work?
Læknablaðið 1996; 82: 371-7
Background; Today there are mainly three methods
for measuring blood pressure, namely by a health
worker at the clinic, by self-monitoring (often called
home monitoring) and ambulatory monitoring.
These methods give different mean values. All pre-
sent studies concerning the relation between high
blood pressure and organ damage are based on
blood pressure measurements at clinics, and there-
fore the predictive values of home and average 24-h
ambulatory measurements are not known. Compar-
ative studies on “white coat effect’’ on blood pressure
in Iceland are lacking. Furthermore, the Icelandic
people have long working days and therefore some
knowledge on blood pressure at work is of interest.
The relation between blood pressure at the clinic
and at work is unknown
Objective: To analyse possible white coat effects of
blood pressure and to compare these measurements
with blood pressure values at work.
Material and methods: During 1993-1994, 84 males
Frá '’heimilislæknisfræði Háskóla íslands, 2,Stefáni Thorar-
ensen hf/Ciba Geigy, 3)lyflaeknisfræði Háskóla íslands,
4,göngudeild háþrýstings á Landspítalanum. Fyrirspurnir,
bréfaskipti: Jóhann Ág. Sigurðsson, Heilsugæslustöðinni
Sólvangi, 220 Hafnarfjörður.
aged 25-65 years were allocated to the study from
five health centres and two hypertension clinics.
Self-measurements of blood pressure were perform-
ed on UA-751 Digital Blood pressure Meter at
home, at work and at the clinic. All measurements
were scheduled between 3 and 5 PM. For compari-
son with blood pressure at the clinical setting, the
pressure was also measured by the doctor using
conventional mercury sphygmomanometer. Three
measurements were recorded at each place but only
one each day.
Results: Good correlation was found between mer-
cury sphygmomanometer and automatic meter mea-
sured at the clinic when measured by standard corre-
lation coefficients (r=0.9; p<0.001). Agreement
analysis demonstrates however, more discrepancy
between these two methods.
Mean blood pressure is similar at the clinic and at
work, but significantly higher than mean blood pres-
sure at home (p<0.001 for both systolic blood pres-
sure and diastolic blood pressure). Possible white
coat (15%) and work related (12%) hypertension
was observed.
Conclusion: The mean blood pressure at work and in
the clinic is similar and higher than that recorded at
home. This strengthens the predictive value of clin-
ical measurements and demonstrates the rise of
blood pressure outside the home is not only due to a
white coat effect. Self measurements at home can be
useful to detect white coat phenomena. Comparison
of self-measurements at work and at home can per-
haps help to detect these effects. The agreement
between the automatic blood pressure meter and
the conventional mercury sphygmomanometer is
unsatisfactory for clinical purposes and therefore
the methods are not interchangeable.