Pediatric Home Blood Pressure Monitoring: Feasibility and Concordance with Clinic-Based Manual Blood Pressure Measurements

Background:

Cardiovascular organ damage is evident in children with elevated blood pressure (EBP) and hypertension (HTN) at diagnosis,¹ suggesting identification occurs late in the disease process. American Academy of Pediatrics’ (AAP) guidelines for HTN diagnosis² specified that children demonstrate persistently EBP at three separate visits for diagnosis. Home blood pressure monitoring (HBPM) may reduce the number of in-person visits needed prior to receiving a HTN diagnosis.³ HBPM is useful in adult HTN diagnosis⁴ and is recommended by the European Society of Hypertension for evaluation of pediatric white coat HTN.⁵ Given challenges associated with bringing children into offices and the rise of telehealth, it is imperative to understand whether HBPM offers a feasible and accurate adjunct in pediatric HTN diagnosis.

Methods:

The SARS-CoV-2 pandemic prematurely concluded a quality improvement collaborative improving pediatric HTN guideline compliance (NCT03783650). Six urban, pediatric primary care clinics associated with a tertiary care center and enrolled in the original study were recruited. After suspending in-person visits from mid-March 2020 through June 2020, clinics were open for all non-infectious, in-person visits. Visit volumes were approximately 20% lower than the comparable period in 2019, related to limiting infectious-type visits. Clinics maintained high performance on quality measures during the pandemic.

A research coordinator phoned English-speaking patients aged three to twenty-two years old, previously identified during the original study as having one prior EBP measurement. Patients had a visit between November 2018 and March 2020 and were contacted between November 2020 and May 2021. Following telephone consent, patients returned to clinic to obtain a HBPM device with appropriately sized cuff and receive education on its use, including recording three morning and three evening measurements for seven consecutive days. Additionally, each patient underwent two manual BP measurements. Participants were asked to text, email, or fax pictures of HBPM measurements. Potential participants were contacted up to five times for consent, followed-up with to reschedule missed appointments, and contacted up to 10 times to obtain HBPM data.

HBPM measurements were averaged and staged according to AAP guidelines.² Patients with HBPM measurements categorized in the same stage (normal, elevated, Stage 1 or Stage 2) as their average manual clinic BP were considered concordant. Patients with discordant measurements were referred to a pediatric nephrologist for “gold standard” BP staging, which included ambulatory blood pressure monitoring (ABPM) if older than eight years old or clinical diagnosis via repeated BP measurements from experienced nephrology clinicians if younger.

Results:

294 patients who met inclusion criteria were identified at the six clinics; 92 (31%) consented to participate in the study and were scheduled for in-person visits (mean age 10.0, standard deviation 5.1). Of these, 72 (78%) presented to clinic for HBPM teaching and manual BP measurements. Despite up to 10 reminder phone calls, only 26 patients (36%) provided HBPM measurements and 14 completed all 42 measurements as instructed. Thirteen (50%) of the 26 patients with HBPM data submitted had discordant BP classification when comparing HBPM to manual BP measurements.

Of those discordant patients, nine subsequently presented for a pediatric nephrology referral and six received ABPM. Of those, four had ABPM BP classification concordant with manual BP classification and discordant with HBPM while two had ABPM classification discordant with manual BP classification. Of the three patients too young for ABPM, one had nephrologist classification concordant with manual BP and discordant with HBPM.

Discussion:

In this feasibility and concordance study of pediatric HBPM in an urban, majority minority population during the SARS-CoV-2 pandemic only one-third of consenting patients who appeared for an in-clinic BP measurement and HBPM training provided HBPM data, despite up to 10 contacts from a research coordinator. Of those who did provide HBPM, many did not complete all HBPM as instructed and one-half had HBPM classifications that were discordant from manual BPs obtained in clinic. While willingness to return to clinic for follow up of EBP may be affected by the SARS-CoV-2 pandemic, HBPM data submission did not require in-person contact. Conducting clinical research during a pandemic presents unique challenges for recruitment, retention and data collection, requiring even closer collaboration with clinical site leaders and overwhelming support for participants. It is unlikely that the multiple outreaches from the study team to obtain HBPM data could be replicated by primary care practitioners outside of a study environment, suggesting even lower HBPM response rates could be observed in real-world HBPM implementation. As HBPM classifications were not consistently aligned with manual BP or ABPM classifications, it is unclear if this modality can reduce clinic visits, be used in telemedicine settings or speed pediatric HTN diagnosis. More study is needed outside of the SARS-CoV-2 pandemic to confirm this finding with larger cohorts and in other contexts such as in children with diagnosed hypertension or out of clinic BP measurements from other providers such as school nurses or community health workers.

Figure 1:

Flowchart of Study Patients