Implementation of the Chronic Care Model to Reduce Disparities in Hypertension Control: Benefits Take Time

Abstract

Background: The Chronic Care Model (CCM) has been endorsed by experts to reduce disparities in chronic disease outcomes but benefits may be slow to appear in low-income populations. Objective: To evaluate the effect of CCM implementation on systolic blood pressure (SBP) control in minority patients with diabetes mellitus (DM). Design: Retrospective study from 2012 to 2016 in two primary care clinics with primarily uninsured, Hispanic patients. Patients: Four 2-year cohorts of patients aged 18–75 with DM and SBP ≥ 140 mmHg on HTN drugs in year 1 and SBP measured 1 year later in year 2. Intervention: Implementation of CCM for DM in January 2014 involved: electronic medical record revision, a DM registry, hypertension (HTN) treatment protocol, team education, performance feedback, and case management. Main Measure: SBP < 140 mmHg in year 2. Key Results: Of 2354 patients, the mean age was 56.2 (SD 9.5), baseline SBP 153.8 (SD 14.9) mmHg, and 79.8% Hispanic. Last SBP < 140 mmHg was 58.4% for cohort 1 (2012–2013) and 68.5% for cohort 4 (2015–2016). Adjusted odds ratios (AORs) for SBP control versus cohort 1 were 1.35 (95% CI 1.07, 1.69) for cohort 3 (2014–2015) and 2.13 (95% CI 1.60, 2.80) for cohort 4. AORs for SBP control were reduced by 15% per HTN drug at baseline (P = 0.001), 9% per HTN drug added at last SBP (P = 0.024), and 22% for multi-dose HTN drugs (P = 0.004). Among patients with persistent elevated SBP and represented in multiple cohorts, AORs for control were still over 2-fold higher for cohort 4 versus cohort 1. Conclusions: After adopting the CCM for primarily Hispanic patients with DM, SBP control increased significantly despite treatment with fewer HTN drugs. Yet improvement took 3–4 years, suggesting that financial rewards for using the CCM to achieve improved clinical outcomes for low-income, minority patients may be delayed.