Value of Mapping Techniques for Planning and Quality Improvement Around the Prevention, Identification, and Management of Hypertension
Authors: Green G. , DeFosset A. , Barragan N. , Kuo T. 
Published: August 2020

Clinical care practices can be optimized to better prevent, identify, and manage hypertension, especially in safety‐net clinics which primarily serve patients at higher risk for related complications. Nearly 30% of American adults have pre‐hypertension. Another 32% of adults have hypertension; 17% of them are undiagnosed, while 46% are uncontrolled. Although recommended best practices exist for the prevention, identification, and management of hypertension, safety‐net clinics often have limited resources and staff with which to implement them; consequently, it is important to target and prioritize efforts. The Los Angeles County (LAC) Department of Public Health (DPH) seeks to improve care practices to better prevent pre‐hypertension, identify undiagnosed hypertension, and manage uncontrolled hypertension. Understanding the relative prevalence of these conditions using clinical data from across LAC and overlaid with community‐level hypertension data can help identify “hot spot” areas to focus efforts that benefit patients in both the clinical and community setting.

DPH conducted descriptive and geospatial analysis using two distinct datasets: (1) retrospective clinic data (pre‐, undiagnosed, and uncontrolled hypertension) of patients at 18 sites of one large federally qualified health center (FQHC) system in LAC and (2) health district‐level hypertension prevalence data from the 2015 Los Angeles County Health Survey. This mapping was used to answer two questions: (1) To what extent do clinic levels of pre‐, undiagnosed, or uncontrolled hypertension correspond to levels of hypertension in surrounding communities? and (2) How can layering/mapping data in this way help identify concrete policy and practice opportunities to optimize care practices and outreach by safety‐net clinics?

Patients at 18 sites of one large FQHC system in LAC, overlaid with hypertension prevalence for all residents of Los Angeles County.

Site‐level pre‐hypertension rates ranged from 11.0% to 37.5%, undiagnosed hypertension rates were between 0.5% and 4.8%, and uncontrolled hypertension rates spanned from 2.0% to 33.9%. Community‐level hypertension rates ranged from 13.0% to 29.8%. Site‐level rates had varying alignment with the community‐level hypertension prevalence. Sites with higher rates of either undiagnosed and uncontrolled hypertension tended to be in communities with higher hypertension prevalence, while site‐level pre‐hypertension rates had no consistent relationship with community‐level hypertension prevalence.

Using these mapping techniques helped identify concrete opportunities for targeted learning and quality improvement efforts around care practices in the region. For instance, several clinic sites were located in areas with high community hypertension, but with low undiagnosed or uncontrolled hypertension rates among patients. These sites could serve as models for successful care practices for clinics that experience worse outcomes.

FQHC systems can establish protocol to routinely query medical records for patients that meet criteria for pre‐, undiagnosed, or uncontrolled hypertension, and engage these patients in a prevention or treatment plan. FQHC systems can use mapping to examine rates of these conditions in the context of surrounding community‐level hypertension prevalence and to identify sites to prioritize for quality improvement around hypertension care guidelines and community outreach to address this health problem.

Centers for Disease Control and Prevention.