Adherence to Long-Term Therapies - Evidence for Action
(2003; 211 pages) View the PDF document
Table of Contents
View the documentPreface
View the documentAcknowledgements
View the documentScientific writers
View the documentIntroduction
View the documentTake-home messages
Open this folder and view contentsSection I - Setting the scene
Open this folder and view contentsSection II - Improving adherence rates: guidance for countries
Close this folderSection III - Disease-Specific Reviews
Open this folder and view contentsChapter VII - Asthma
Open this folder and view contentsChapter VIII - Cancer (Palliative care)
Open this folder and view contentsChapter IX - Depression
Open this folder and view contentsChapter X - Diabetes
Open this folder and view contentsChapter XI - Epilepsy
Open this folder and view contentsChapter XII - Human immunodeficiency virus and acquired immunodeficiency syndrome
Close this folderChapter XIII - Hypertension
View the document1. Prevalence of adherence to pharmacotherapy in patients with hypertension
View the document2. Impact of adherence on blood pressure control and cardiovascular outcome
View the document3. Adherence to non-pharmacological treatment
View the document4. Factors contributing to adherence
View the document5. Interventions for improving adherence
View the document6. Conclusions
View the document7. References
Open this folder and view contentsChapter XIV - Tobacco smoking cessation
Open this folder and view contentsChapter XV - Tuberculosis
Open this folder and view contentsAnnexes
Open this folder and view contentsWhere to find a copy of this book
 

1. Prevalence of adherence to pharmacotherapy in patients with hypertension

Despite the availability of effective treatment, over half of the patients being treated for hypertension drop out of care entirely within a year of diagnosis (15) and of those who remain under medical supervision only about 50% take at least 80% of their prescribed medications (16). Consequently, because of poor adherence to antihypertensive treatment, approximately 75% of patients with a diagnosis of hypertension do not achieve optimum blood-pressure control (13,18).

Estimates of the extent to which patients adhere to pharmacotherapy for hypertension vary between 50 and 70%. This variation relates to differences in study groups, duration of follow-up, methods of assessment of adherence and drug regimens used in different studies. For example, studies that defined adherence as an 80% ratio of days on which medication was dispensed to days in the study period, reported adherence rates ranging from 52 to 74% (19,20). Other studies that have investigated discontinuation of antihypertensives have reported adherence rates of 43 to 88% (21 - 24). Furthermore, it has been estimated that within the first year of treatment 16 to 50% of patients with hypertension discontinue their antihypertensive medications, and among those who continue their therapy in the long term, missed doses of medication are common (25). These figures differ for newly-diagnosed patients and those with chronic, long-standing hypertension (26).

Another source of variation that could explain the differences in rates of adherence is the method used to measure adherence. Examples of methods used include calculating the percentage of pills taken in a specific time period, the percentage of patients taking 80% of their pills, the improvement in number of pills taken, the dropouts from treatment and follow-up, and the missed appointments. There are also indirect proxy measures such as change in blood pressure and the achievement of target blood pressure (27).

to previous section
to next section
 
 
The WHO Essential Medicines and Health Products Information Portal was designed and is maintained by Human Info NGO. Last updated: August 29, 2014