Abstract 14501: Process Evaluation of a Double Blind Randomized Controlled Trial to Assess the Efficacy and Safety of a Quadruple Ultra-Low-Dose Treatment for Hypertension Within a Federally Qualified Health Center Network (QUARTET USA)

Abstract

Introduction: This explanatory sequential mixed-methods process evaluation of the QUARTET USA clinical trial (NCT03640312) explores patient and health professional perceptions about the use of low-dose quadruple therapy (LDQT) as a novel strategy for hypertension management. Methods: Sixty-two patients took part in the trial. Survey data were collected from patients to understand their beliefs about blood pressure medications and treatment satisfaction with LDQT. A sub-sample of 13 English and Spanish patients and 11 health professionals, recruited via purposive sampling, took part in semi-structured qualitative interviews. Data collection took place between August 2019 and July 2022. Quantitative data were analyzed using descriptive statistics and cross-tabulations, and the qualitative data were analyzed using thematic analysis. Common themes from the two sets of findings were integrated. Results: 54.3% of patients believed in the necessity of their blood pressure medicines and 40.6% were concerned about the side effects and long-term effects of their medications. At trial completion, 80.4% of the patients were satisfied with the LDQT, 96.4% were certain the benefits of taking LDQT outweighed the disadvantages, and all participants reported that it was convenient to take. Both patients and health professionals found LDQT acceptable because it facilitated patients’ blood pressure control and medication adherence, and reduced patients’ perceived pill burden and adverse reactions. Health professionals stated that a limitation of LDQT was the inability to titrate the dose and that health insurance coverage and inclusion of LDQT in national hypertension guidelines could increase its widespread use. Conclusions: The LDQT strategy was acceptable to patients and health professionals for hypertension treatment. While LDQT therapy generally improved and maintained patients’ blood pressure control, medication adherence, and had a good safety profile, the limitation of its titration inflexibility and medication cost were raised by health professionals. Making LDQT therapy flexible by introducing stepped care combinations and ensuring health insurance coverage could increase its widespread implementation and scale-up.