Blood Pressure Reduction in Black Barbershops

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Victor RG, et al. "A Cluster-Randomized Trial of Blood-Pressure Reduction in Black Barbershops". The New England Journal of Medicine. 2018. 378(14):1291-1301.
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Clinical Question

In non-hispanic black men with uncontrolled hypertension, is community-based (barbershop targeted) pharmacist-directed intervention superior to health promotion alone in reducing blood pressure?

Bottom Line

In non-hispanic black men with uncontrolled hypertension, community-based (barbershop targeted) pharmacist-directed intervention was superior to health promotion alone in reducing blood pressure. Pharmacist-directed intervention was associated with a 27.0mmHg drop in systolic blood pressure compared to health promotion alone, with achievement of BP < 130/80 mmHg in 64% of patients randomized to pharmacist-directed intervention compared to 12% in patients randomized to health promotion alone.

Major Points

Non-hispanic black men have the highest rate of hypertension-related death of any racial, ethnic, or sex group in the United States. [1] There is evidence to suggest that this observation is related to lower rates of physician interaction and hypertension treatment observed within this population. [2] As a result, there has been considerable interest in the implementation and evaluation of interventions designed to bring healthcare providers to black men in the community. Community-based interventions targeting barbershops is a particular area of interest, as at least one small study has shown modest but significant improvements in hypertension control when barbers checked blood pressure and urged patrons with elevated readings to make doctor appointments. [3] A limitation of this study is that even when patients sought medical attention upon the urging of their barbers, treatment was often not escalated by their community providers. Thus, it remained unclear whether a community-based intervention including the ability to initiate and uptitrate anti-hypertensive therapy in the community may result in more effective hypertension control.

The 2018 Blood Pressure Reduction in Black Barbershops trial randomized barbershops (non-Hispanic black owned, with > 95% black clientele, 15+ years in business, and large enough to enroll 25 patrons) in cluster fashion to a pharmacist intervention group, in which barbers encouraged patrons with elevated blood pressure to seek care from pharmacists who met regularly with participants and initiated/uptitrated anti-hypertensive therapy under the supervision of the patient's community provider, versus a control group, in which barbers provided patrons with elevated blood pressure instruction about blood pressure and encouragement to follow up with their community provider to discuss anti-hypertensive therapy. At 6 months, patients randomized to the pharmacist intervention group were noted to have absolute reduction in systolic blood pressure of 27.0mmHg when compared to the control arm. Adverse events were low and similar in both groups. Self rated health and patient engagement were increased in the intervention cohort.

This trial provides compelling evidence that community-based intervention targeting black barbershops involving the delivery of direct care including initiation and uptitration of anti-hypertensive medications is safe and effective in reducing blood pressure in a population known to be at high risk for complications related to poorly controlled blood pressure. Whether this type of intervention will translate into improved clinical outcomes remains unproven and will be the subject of future study.


As of April 2018, no guidelines have been published that reflect the results of this trial.


  • Cluster randomized open-label controlled trial
  • N=303
    • Intervention (N=132)
    • Control (N=171)
  • Setting: 78 barbershops in Los Angeles, CA, USA
  • Enrollment: February 2015 - July 2017
  • Duration of follow-up: 6 months
  • Analysis: Intention-to-treat
  • Primary Outcome: Change from baseline to 6 months in systolic blood pressure


Inclusion Criteria

  • Non-hispanic black male
  • ≥ 18 years old
  • Long-term/frequent barbershop patronage
  • Systolic BP ≥ 140mmHg at 2 screenings
  • Complete set of baseline data

Exclusion Criteria

  • Cognitive impairment

Baseline Characteristics

From the intervention group.

  • Demographics: Age 54.4, married 46.6%, high school graduate or above 95.4%, annual income $39,999 or less 49.8%, has a regular provider 77.1%
  • Barbershops: Total number 28, years in business 17.3, number of barbers per shop 4, duration of patronage 10.2 years, frequency of visits per patron once every 2 weeks
  • Comorbidities: BMI 30.8, smoker 33.1%, diabetes 21.2%, hyperlipidemia 34.8%


  • Barbershops cluster randomized 1:1
    • Intervention arm (N=132)
    • Control arm (N=171)
  • Field interviewers screened the clientele at participating barbershops to recruit self-identified regular patrons (≥ 1 haircut every 6 weeks for ≥ 6 months) who were non-Hispanic black men
  • Barbers in shops assigned to the intervention were trained to encourage pharmacist follow-up and measure blood pressure
  • Participants in the control group received instruction about blood pressure, and barbers were trained to discuss the instructional information with participants and encourage follow-up with a provider
  • Participants in both groups received resources to promote cohort retention and blood pressure reduction
    • Results of two blood pressure screenings
    • Follow-up recommendations
    • Identification cards
    • Follow-up calls in 3 months
    • Culturally-specific health sessions
    • Vouchers for monthly haircuts
  • Two full-time doctoral-level pharmacists received specialized training and certification as hypertension clinicians and regularly reviewed each participant's treatment with physician hypertension specialists
  • In intervention groups only, pharmacists met regularly with participants in barbershops assigned to the intervention, prescribed an antihypertensive drug regimen, measured blood pressure, encouraged lifestyle changes, and monitored electrolyte levels
  • In intervention groups only, pharmacists interviewed participants to generate peer-experience stories, reviewed blood pressure trends, and gave participants $25 per pharmacist visit to offset costs of generic drugs and transportation to pharmacies
  • Two-drug therapy using amlodipine plus a long-acting angiotensin-receptor blocker (ARB) or angiotensin-converting-enzyme (ACE) inhibitor preferred followed by thiazide indapamide as third-line agent
  • After each encounter with a participant, pharmacists sent progress notes to the given participant's health care provider
  • Patients without an existing provider to sign the collaborative practice agreement were supervised by a designated community physician
  • Field interviewers completed 30 minute, in person, computer-based questionnaires in barbershops to participants in both groups at baseline and at 6 months
  • All blood pressures were measured in barbershops using a validated oscillometric monitor
    • At each visit, five sequential blood pressure readings were taken, and the last three were averaged to determine the result
    • For 6 months, pharmacists and some barbers measured blood pressure monthly to monitor drug therapy in the intervention group but not the control group
  • Pharmacists used a point of care validated test to measure blood electrolytes and creatinine after each medication change


Comparisons are pharmacist intervention vs. control

Primary Outcomes

Change in systolic blood pressure (6 months)
-27.0 vs. -9.3; effect size -21.6 (95% CI -28.4 to -14.7); p < 0.001

Secondary Outcomes

Change in diastolic blood pressure (6 months)
-17.5 vs. -4.3; effect size -14.9 (95% CI -19.6 to -10.3); p < 0.001
Blood pressure < 140/90 (6 months)
118 (89.4%) vs. 55 (32.2%); OR 3.4 (95% CI 2.5-4.6); p < 0.001
Mean number of BP medications per participant
2.6 vs. 1.4; Mean difference 1.9 (95% CI 1.3-2.4); p < 0.001

Adverse Events

  • In the intervention group, transient acute kidney injury developed in 3 participants (all on indapamide). The acute kidney injury resolved with stopping indapamide in all cases. No data on acute kidney injury were obtained on control group participants.


  • 40% of the participants did not have a doctor to sign the collaborative practice agreement, and were thus assigned a community physician supervising doctor. Given that this resource may not exist outside the context of a clinical trial, generalizability is somewhat limited and "real world" results may be less positive.
  • Assignment through cluster randomization could not be blinded, leading to the possibility of ascertainment bias (e.g., patients in the intervention group measured as having lower blood pressures). This is mitigated by protocoled BP measurements, use of independently contracted field interviewers to obtain measurements, and direct uploading of BP measurements to a centralized source.
  • The BP goal in the intervention group was lower (130/80) than what was likely used in the control group (presumed 140/80, per guidelines of the time). This was chosen because the definition of elevated blood pressure is lower outside the healthcare setting. This may have lead to overestimation of the effect of the community-based intervention itself.
  • Short duration of follow up (6 months) limits ability to comment on the long term durability of the results, or whether the observed BP reduction translates into clinical outcomes.


  • Study supported by the National Institutes of Health

Further Reading

  1. Benjamin EJ et al. Heart Disease and Stroke Statistics-2017 Update: A Report From the American Heart Association. Circulation 2017. 135:e146-e603.
  2. Victor RG et al. Factors associated with hypertension awareness, treatment, and control in Dallas County, Texas. Arch. Intern. Med. 2008. 168:1285-93.
  3. Victor RG et al. Effectiveness of a barber-based intervention for improving hypertension control in black men: the BARBER-1 study: a cluster randomized trial. Arch. Intern. Med. 2011. 171:342-50.