Trends in Ambulatory Blood Pressure Monitoring in Five High-Volume Medical Centers

In 2015, the U.S. Preventive Services Task Force (USPSTF) issued a grade A recommendation for ambulatory blood pressure monitoring (ABPM) for the confirmation of a diagnosis of hypertension outside of clinic settings. ABPM is also increasingly used to characterize complex blood pressure (BP) syndromes, particularly among patients with autonomic dysfunction, conditions involving both hypertension and hypotension, or patients presenting for a syncope evaluation. Moreover, in June 2019, the Centers for Medicare and Medicaid Services (CMS) determined that “the evidence is sufficient to cover ABPM for the diagnosis of hypertension in Medicare beneficiaries,” specifically those with suspected white coat hypertension or masked hypertension.¹ This decision paved the way for expanded reimbursement of an annual ABPM for CMS beneficiaries. However, U.S. trends in ABPM use since this decision are unclear. In fact, some have questioned whether reimbursement levels are adequate to influence referrals for ABPM (maximum non-facility reimbursement <$50). Indeed, reimbursement for ABPM has been variable and consistently lower in the U.S. compared with several industrialized nations.²

In this letter, we used data from five large, geographically distinct, medical centers with ABPM (Beth Israel Deaconess Medical Center, MA; Cedars-Sinai Medical Center, CA; Geisinger Health, PA; University of North Carolina, NC; and University of Texas Southwestern, TX) to examine temporal trends in ABPM. We hypothesized that ABPM utilization increased due to its clinical utility, independent of reimbursements. Note data was available from four centers since 2010 and from all five centers (Cedars-Sinai included) since 2017.

Five large medical centers examined their electronic records for ABPM orders or reports. There was clear evidence of an increasing volume of ABPMs over time across the five centers (Figure). Prior to the USPSTF recommendation, ABPM utilization increased 72% (based on four centers with historic data). From 2015–2017, immediately after the USPSTF recommendation, utilization among four centers (excluding Cedars-Sinai) increased 130%. From 2017 to 2019, after the ACC/AHA guidelines, utilization across the five centers increased 64%, while from 2019 to 2022, after the CMS reimbursement expansion, utilization increased 23%.

Figure 1.

Tabulation of ambulatory blood pressure monitoring (ABPM) assessments performed from 2012 to 2022. The line graph with numbers represents the total. Each bar represents a unique center. ABPM utilization estimates were based on billing codes for Geisinger Health and University of Texas Southwestern (UTSW). For Beth Israel Deaconess Medical Center (BIDMC), Cedars-Sinai (CS), and University of North Carolina, ABPM utilization estimates were based on counts of ABPM reports.

Notably, the increased utilization preceded the 2019 CMS decision to expand reimbursement and was observed among centers that did not bill for ABPMs (Beth Israel Deaconess Medical Center). Although there was a dip in ABPM utilization during the start of the COVID-19 pandemic in 2020, this was temporary, with numbers exceeding the pre-pandemic level as early as 2021.

CMS currently recommends ABPM for beneficiaries to evaluate for white coat or masked hypertension.¹ This decision was based on a comprehensive review of the evidence on the clinical utility of ABPM to improve health outcomes among patients with suspected white coat hypertension, who are not on treatment, patients with white coat hypertension, who are actively treated, and patients with suspected masked hypertension. Based on observational evidence, drafters concluded that there was sufficient evidence that a more accurate diagnosis of hypertension could inform physician treatment and improve long-term outcomes.

In addition, there is increasing value in ABPM for conditions beyond white coat hypertension and masked hypertension. Elevated BP variability, morning surge, and nocturnal hypertension are all conditions associated with increased risk for cardiovascular disease.³ ABPM can also characterize conditions involving autonomic dysregulation of BP, including orthostatic hypotension,⁴ and episodic hypotensive symptoms. These indications are not currently covered by CMS but are increasingly common reasons behind referrals for ABPM assessments.

Reimbursement remains an important incentive for health institutions to invest in infrastructure for medical assessments such as ABPM. There is currently limited availability and access to ABPM throughout the country, depriving many patients of this useful clinical tool to understand fluctuations in their BP throughout the day. A similar situation existed in Australia prior to November 2021, when the government added reimbursement of ABPM to the Australian Medicare Benefits Schedule.⁵ Since this expanded reimbursement, interest and availability of ABPMs have increased dramatically throughout the country. Our finding that ABPM use in the U.S. has increased largely without effect from reimbursement raises the question of how many more assessments might be performed if reimbursement was more adequate and expanded to its broader clinical applications.

Our study has limitations. We did not have sufficient detail to characterize referral patterns across U.S. geographies and medical specialties or track the impact of reimbursement on ABPM referral patterns. Moreover, the impact of reimbursement on access for older patients or patients with lower socioeconomic status should be a focus of subsequent work.

In conclusion, while our sample is small, data from five large centers throughout the country suggest that ABPM use is increasing over time and may be driven by factors distinct from reimbursement. This finding highlights the increased clinical value from ABPM assessments perceived by ordering clinicians. Whether a more favorable reimbursement rate and comprehensive coverage would drive even greater utilization and improve access to this evidence-based form of BP measurement is an important subject for subsequent research.

Abbreviations used:

ABPM

ambulatory blood pressure monitoring

CMS

Centers for Medicare and Medicaid Services

DBP

diastolic blood pressure

SBP

systolic blood pressure