Kaiser Permanente Northern California Hypertension Control Program

Hypertension, a major contributor to cardiovascular disease, affects 29% of the adult population in the United States (n=65 million). Effective therapies to control hypertension have been available for >50 years; however, from 2001 to 2002, fewer than half of patients with hypertension had controlled blood pressure, according to researchers. Although there are many quality improvement strategies for hypertension control, there have been no successful, long-term programs sustained over a long period described to date.

Kaiser Permanente Northern California (KPNC) is a not-for-profit, integrated healthcare delivery system caring for >2.3 million adult members at 21 hospitals and 45 medical facilities, with a network of >7000 physicians. KPNC developed a system-level, multifaceted quality improvement program for hypertension in 2000. Details of the program and associated results for the period from 2001 to 2009 were outlined recently in JAMA [2013;310(7):699-705].

The KPNC program included 5 major components: (1) a health system-wide hypertension registry; (2) hypertension control rates; (3) development of an evidence-based practice guideline; (4) medical assistant visits for follow-up measurements; and (5) promotion of single-pill combination (SPC) therapy.

Members with hypertension were identified quarterly using outpatient diagnostic codes, pharmacy data, and hospitalization records from health plan databases. Diagnoses were validated through chart review audits of random samples of identified members. Inclusion criteria were (1) ≥2 hypertension diagnoses coded in primary care visits in the prior 2 years; (2) ≥1 primary care hypertension diagnoses and ≥1 hospitalizations with a primary or secondary hypertension diagnosis in the prior 2 years; (3) ≥1 primary care hypertension diagnoses and ≥1 filled prescriptions for hypertension medication within the prior 6 months; or (4) ≥1 primary care hypertension diagnoses and ≥1 stroke-related hospitalizations or a history of coronary disease, heart failure, or diabetes mellitus.

Hypertension control was defined per National Committee for Quality Assurance (NCQA) Healthcare Effectiveness Data and Information Set (HEDIS) specifications: both systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mm Hg. Control reports were generated every 1 to 3 months for each KPNC medical center and distributed to the center directors.

The evidence-based, 4-step hypertension control algorithm was developed in 2001. The guideline was updated every 2 years based on emerging randomized trial evidence and national guidelines. Clinicians in the KPNC network were encouraged to follow the algorithm unless clinical discretion required otherwise.

All of the KPNC medical centers utilized a medical assistant follow-up visit in 2007. The visit was typically scheduled 2 to 4 weeks after an adjustment in medication. The assistant measured blood pressure and informed the primary care physician, who then directed treatment decisions and follow-up planning.

SPC therapy with lisinopril-hydrochlorothiazide was incorporated into the regional guideline in 2005 as being optional for initial treatment and recommended as a step-2 therapy.

Between 2001 and 2009, the KPNC hypertension registry increased 15.4% of adult KPNC membership (n=349,937) to 27.5% (n=652,763). Among the registry members, mean age was 63 years, and more than half were women. Diabetes was common and prevalence increased from 25.6% in 2001 to 28.5% in 2009.

Within KPNC, the NCQA HEDIS commercial measurement for hypertension control increased from 43.6% to 80.4% during the study period (P<.001 for trend). In comparison, the national mean NCQA HEDIS commercial measurement increased from 55.4% to 64.1%. California mean NCQA HEDIS commercial rates of hypertension control were similar to the national rates from 2006 to 2009 (63.4% to 69.4%).

In summary, the authors commented, “Implementation of a large-scale hypertension program was associated with improvement in hypertension control rates between 2001 and 2009. Key elements of the program included establishment of a comprehensive hypertension registry, development and sharing of performance metrics, evidence-based guidelines, medical assistant visits for blood pressure measurement, and SPC pharmacotherapy.”