When it comes to the diagnosis of high blood pressure, or hypertension, in patients, many health organizations, including the American Heart Association, recommend either Ambulatory Blood Pressure Monitoring (ABPM) or home blood pressure monitoring (HBPM). This is recommended for most patients with high in-office BP readings.
These two methods of diagnosing hypertension are often considered superior to solely relying on in-office BP readings, which might offer a misleading picture of your patients’ health and could lead to misdiagnosis and over or under-medication.
But what are the differences between ABPM and HBPM? Does one practice offer any inherent benefits over the other?
Ambulatory Blood Pressure Monitoring
ABPM provides blood pressure readings over the course of 24 hours or more. By looking at how blood pressure changes throughout the day and night, you are better equipped to make treatment decisions for your patients’ health.
One of the largest most significant differences between ABPM and HBPM is the ability to collect data at night. Nocturnal BP data can be a strong indicator of cardiovascular disease risk and is currently only accessible with ABPM. 
In general, ABPM does a better job of capturing variability of BP throughout the day, including morning surges in BP, which HBPM is not able to capture. Overall, the use ABPM will typically capture more BP data points than the use of HBPM, giving a more complete picture of the patient’s BP.
Home Blood Pressure Monitoring
HBPM requires patients to monitor their own blood pressure, either at home, or in a setting where regular blood pressure monitoring is possible (such as a local pharmacy with a BP kiosk) over a predetermined span of time. Like ABPM, HBPM can give insights to clinicians that can improve control of BP, diagnose white-coat hypertension or masked hypertension, and predict cardiovascular risk.
In general, HBPM is more accessible to patients and less expensive than ABPM. Some clinicians prefer HBPM over ABPM simply because it is less complex and can be a bit more patient friendly.
While overall the advantages outweigh the disadvantages, there are some drawbacks to HBPM. Performing accurate blood pressure measurements on oneself does require a certain amount of training that goes beyond that of the average patient’s knowledge.
Additionally, not all home blood pressure monitors currently available on the market are validated for clinical accuracy. But all-in-all, HBPM can provide great longitudinal BP data and has shown to be both accessible and cost-friendly for patients.
What the Evidence Says
Comparing ABPM and HBPM, studies suggest ABPM is correlated with better health outcomes. Also, while ABPM is often associated with more upfront costs, evidence indicates that ABPM is actually more cost-effective in the long-term.
However, access to ABPM studies is still an issue especially in high-potential markets such as in the United States due to various barriers to adoption (e.g., lack of clinician awareness to guidelines, limited insurance coverage, clinician beliefs about ABPM, etc.). This is why it is important to raise awareness of -- and develop innovative solutions for expanding access to -- ABPM.
So, what is right for your patient? Unfortunately, there is no one-size-fits-all answer to this question.
It all depends on your patient, their preferences and health care coverage, the access to care, the type of data you are looking for, and the quality of the data you need.
-  K. Kario, "Morning Surge in Blood Pressure and Cardiovascular Risk," Hypertension, vol. 56, no. 5, pp. 765-773, 2010.
-  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6159400/
-  https://academic.oup.com/ajh/article/31/8/919/4999720?login=true
-  https://www.health.harvard.edu/blog/home-blood-pressure-monitors-arent-accurate-201410297494
-  https://www.ahajournals.org/doi/full/10.1161/HYPERTENSIONAHA.118.11715