Analysis of Therapeutic Inertia and Race and Ethnicity in the Systolic Blood Pressure Intervention Trial: A Secondary Analysis of a Randomized Clinical Trial

Abstract

Importance: Therapeutic inertia may contribute to racial and ethnic differences in blood pressure (BP) control.

Objective: To determine the association between race and ethnicity and therapeutic inertia in the Systolic Blood Pressure Intervention Trial (SPRINT).

Design, setting, and participants: This cross-sectional study was a secondary analysis of data from SPRINT, a randomized clinical trial comparing intensive (<120 mm Hg) vs standard (<140 mm Hg) systolic BP treatment goals. Participants were enrolled between November 8, 2010, and March 15, 2013, with a median follow-up 3.26 years. Participants included adults aged 50 years or older at high risk for cardiovascular disease but without diabetes, previous stroke, or heart failure. The present analysis was restricted to participant visits with measured BP above the target goal. Analyses for the present study were performed in from October 2020 through March 2021.

Exposures: Self-reported race and ethnicity, mutually exclusively categorized into groups of Hispanic, non-Hispanic Black, or non-Hispanic White participants.

Main outcomes and measures: Therapeutic inertia, defined as no antihypertensive medication intensification at each study visit where the BP was above target goal. The association between self-reported race and ethnicity and therapeutic inertia was estimated using generalized estimating equations and stratified by treatment group. Antihypertensive medication use was assessed with pill bottle inventories at each visit. Blood pressure was measured using an automated device.

Results: A total of 8556 participants, including 4141 in the standard group (22 844 participant-visits; median age, 67.0 years [IQR, 61.0-76.0 years]; 1467 women [35.4%]) and 4415 in the intensive group (35 453 participant-visits; median age, 67.0 years [IQR, 61.0-76.0 years]; 1584 women [35.9%]) with at least 1 eligible study visit were included in the present analysis. Among non-Hispanic White, non-Hispanic Black, and Hispanic participants, the overall prevalence of therapeutic inertia in the standard vs intensive groups was 59.8% (95% CI, 58.9%-60.7%) vs 56.0% (95% CI, 55.2%-56.7%), 56.8% (95% CI, 54.4%-59.2%) vs 54.5% (95% CI, 52.4%-56.6%), and 59.7% (95% CI, 56.5%-63.0%) vs 51.0% (95% CI, 47.4%-54.5%), respectively. The adjusted odds ratios in the standard and intensive groups for therapeutic inertia associated with non-Hispanic Black vs non-Hispanic White participants were 0.85 (95% CI, 0.79-0.92) and 0.94 (95% CI, 0.88-1.01), respectively. The adjusted odds ratios for therapeutic inertia comparing Hispanic vs non-Hispanic White participants were 1.00 (95% CI, 0.90-1.13) and 0.89 (95% CI, 0.79-1.00) in the standard and intensive groups, respectively.

Conclusions and relevance: Among SPRINT participants above BP target goal, this cross-sectional study found that therapeutic inertia prevalence was similar or lower for non-Hispanic Black and Hispanic participants compared with non-Hispanic White participants. These findings suggest that a standardized approach to BP management, as used in SPRINT, may help ensure equitable care and could reduce the contribution of therapeutic inertia to disparities in hypertension.

Trial registration: ClinicalTrials.gov identifier: NCT01206062.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Zheutlin reported receiving grants from National Institutes of Health (NIH) during the conduct of the study. Dr Derington reported receiving institutional funds from Amarin Research funds outside the submitted work, and being a former recipient of American Heart Association grant #19POST34380226/Derington/2019. Dr Cohen reported receiving grants from the NIH (K23-HL133843, R01-HL153646, U01-HL160277, U01-TR003734, R01-DK123104, U24-DK060990) and the American Heart Association (Bugher Award) outside the submitted work. Dr Cushman reported receiving grants from a NIH interagency agreement, with no salary, during the conduct of the study, and institutional grant funding from Eli Lilly unrelated to the current manuscript. Dr Greene reported receiving personal fees for statistical consulting from Janssen Pharmaceuticals, DURECT Corporation, and Pfizer Inc and grants for statistical consulting from AstraZeneca, CSL Limited, and Boehringer-Ingelheim outside the submitted work. Dr Bress reported receiving grants from the National Heart, Lung, and Blood Institute during the conduct of the study and grants from Amgen and Amarin outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Flowchart Showing Eligibility Criteria for Inclusion in Current Study

SBP indicates systolic blood pressure; SPRINT, Systolic Blood Pressure Intervention Trial.

Figure 2.. Predicted Prevalence of Therapeutic Inertia by Race and Ethnicity in the Standard and Intensive Treatment Arms of the Systolic Blood Pressure Intervention Trial

Predicted probability of therapeutic inertia is shown for participants randomized to the standard treatment arm (A) and intensive treatment arm (B). This figure represents an average model-based, multivariable-adjusted estimated probability of therapeutic inertia at each participant visit by race and ethnicity averaged across the observed values of all other covariates in the logistic regression model. Prediction values are based on model 3, which is adjusted for race and ethnicity and time in addition to age, sex, education, employment, living with others, insurance status, source of care, smoking status, body mass index, depression, statin use, and aspirin use, as well as most recent visit SBP, eGFR, serum potassium, serum sodium, number of antihypertensive medications, prior mTIS, angiotensin converting enzyme inhibitor/angiotensin converting enzyme inhibitor, calcium channel blocker, thiazide diuretic, loop diuretic, beta-blocker, alpha-blocker, number of nonantihypertensive medications, and serious adverse events reported within 1 month before the study visit..