Background
Change in the prevalence of raised blood pressure could be due to
both shifts in the entire distribution of blood pressure (representing the
combined effects of public health interventions and secular trends) and
changes in its high-blood-pressure tail (representing successful clinical
interventions to control blood pressure in the hypertensive population). Our
aim was to quantify the contributions of these two phenomena to the
worldwide trends in the prevalence of raised blood pressure.
Methods
We pooled 1,018 population-based studies with blood pressure
measurements on 88.6 million participants from 1985 to 2016. We first
calculated mean SBP, mean DBP and prevalence of raised blood pressure by sex
and 10-year age group from 20-29 years to 70-79 years in each study, taking
into account complex survey design and survey sample weights, where
relevant. We used a linear mixed effect model to quantify the association
between (probit-transformed) prevalence of raised blood pressure and
age-group- and sex-specific mean blood pressure. We calculated the
contributions of change in mean SBP and DBP, and of change in the
prevalence-mean association, to the change in prevalence of raised blood
pressure.
Results
In 2005-2016, at the same level of population mean SBP and DBP, men
and women in south Asia and in central Asia, Middle East and north Africa
would have the highest prevalence of raised blood pressure, and men and
women in the high-income Asia Pacific and high-income western regions would
have the lowest. In most region-sex-age groups where the prevalence of
raised blood pressure declined, one half or more of the decline was due to
the decline in mean blood pressure. Where prevalence of raised blood
pressure has increased, the change was entirely driven by increasing mean
blood pressure, offset partly by the change in the prevalence-mean
association.
Conclusions
Change in mean blood pressure is the main driver of the worldwide
change in the prevalence of raised blood pressure, but change in the
high-blood-pressure tail of the distribution has also contributed to the
change in prevalence, especially in older age groups.