Physician characteristics as predictors of blood pressure control in patients enrolled in the hypertension improvement project (HIP)

Variation in the diagnosis and control of hypertension is not explained by conventional variables: Cross-sectional database study in English general practice

Background

Hypertension is a major cause of preventable disability and death globally and affects more than one in four adults in England. Unwarranted variation is variation in access, quality, outcome or value which is unexplained by differences in the condition or patient characteristics and which reduces quality and efficiency. Distinguishing unwarranted from variation due to clinical, organisational or patient factors can be challenging. We carried out this study to explore inter-practice variation in the diagnosis and management of hypertension in the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) network database, a large, representative surveillance database.

Methods and finding

We carried out a cross-sectional study using primary care data extracted from the electronic health records of 1,271,419 adults registered at RCGP RSC general practices on 31^st December 2016. Logistic regression was used to indirectly standardise practice-level hypertension prevalence and control against the RCGP RSC population, adjusted for age, gender, ethnicity, deprivation, co-morbidity, NHS region and practice size. Inter-practice variation was demonstrated using funnel plots with 95% and 99.8% control limits. The prevalence of detected hypertension was 18.4% (95% CI 18.4–18.5), n = 234,165. Uncontrolled hypertension was present in 146,553 of 196,052 individuals, 25.2% (25.1–25.4), in whom blood pressure had been recorded in the previous year. Hypertension management varied markedly between practices with a three-fold difference in prevalence, 13.5–38.4%, and a four-fold difference in the proportion of uncontrolled hypertension, 11.8–47.9%. Despite adjustment for sociodemographic and practice characteristics funnel plots demonstrated marked over-dispersion.

Conclusions

Substantial variation in the prevalence of diagnosed hypertension and the management of hypertension was only partially explained by characteristics captured within a routine dataset. The over-dispersion suggests variation is not fully explained by these factors and that context, behaviour and processes of care delivery may contribute to variation. Routine data sources in isolation to not provide sufficient contextual data to diagnose the causes of variation.

Clinical Operations Variables are Associated With Blood Pressure Outcomes

BACKGROUND

Uncontrolled blood pressure (BP), among patients diagnosed and treated for the condition, remains an important clinical challenge; aspects of clinical operations could potentially be adjusted if they were associated with better outcomes.

OBJECTIVES

To assess clinical operations factors' effects on normalization of uncontrolled BP.

RESEARCH DESIGN

Observational cohort study.

SUBJECTS

Patients diagnosed with hypertension from a large urban clinical practice (2005-2009).

MEASURES

We obtained clinical data on BP, organized by person-month, and administrative data on primary care provider (PCP) staffing. We assessed the resolution of an episode of uncontrolled BP as a function of time-varying covariates including practice-level appointment volume, individual clinicians' appointment volume, overall practice-level PCP staffing, and number of unique PCPs.

RESULTS

Among the 7409 unique patients representing 50,403 person-months, normalization was less likely for the patients in whom the episode starts during months when the number of unique PCPs were high [the top quintile of unique PCPs was associated with a 9 percentage point lower probability of normalization (P<0.01) than the lowest quintile]. Practice appointment volume negatively affected the likelihood of normalization [episodes starting in months with the most appointments were associated with a 6 percentage point reduction in the probability of normalization (P=0.01)]. Neither clinician appointment volume nor practice clinician staffing levels were significantly associated with the probability of normalization.

CONCLUSIONS

Findings suggest that clinical operations factors can affect clinical outcomes like BP normalization, and point to the importance of considering outcome effects when organizing clinical care.

Predictors of lowering SBP to assigned targets at 12 months in the Secondary Prevention of Small Subcortical Strokes study

OBJECTIVE

Lowering blood pressure for secondary stroke prevention remains a challenge. These analyses were conducted to identify factors predicting achievement of SBP targets in the Secondary Prevention of Small Subcortical Strokes (SPS3) study.

METHODS

SPS3 is a randomized trial assigning patients with lacunar stroke to two targets of SBP control (130-149 mmHg or <130 mmHg). Logistic regression models were used to identify patient and SPS3 site characteristics predictive of lowering SBP to target at the 12-month study visit.

RESULTS

Of those above target at baseline (n = 1041), 69% were within their assigned target at 12 months. In the model with baseline characteristics only, those receiving treatment for hypertension at baseline were 68% less likely to achieve target [odds ratio (OR) = 0.32; 95% confidence interval (CI) = 0.17-0.60], whereas those of Hispanic ethnicity were 1.49 times more likely (95% CI = 1.09-2.03) to achieve SBP target. When clinical site characteristics were added to the model, only treated hypertension at baseline remained significant. In addition, management at a larger site (OR = 1.51; 95% CI = 1.03-2.20), SBP in target at 6 months (OR = 2.39; 95% CI = 1.79-3.19), and medication adherence (OR = 2.73; 95% CI = 1.51-4.95) were positively associated with achieving target SBP. Missed appointments (OR = 0.55; 95% CI = 0.41-0.73) were negatively associated with lowering SBP to target at 12 months.

CONCLUSION

These results demonstrate that it is feasible to achieve targets of SBP control in this multiethnic stroke cohort across multiple sites and countries. The results highlight the important variables reflecting clinical site management.

The counseling African Americans to Control Hypertension (CAATCH) Trial: baseline demographic, clinical, psychosocial, and behavioral characteristics

Background

Effectiveness of combined physician and patient-level interventions for blood pressure (BP) control in low-income, hypertensive African Americans with multiple co-morbid conditions remains largely untested in community-based primary care practices. Demographic, clinical, psychosocial, and behavioral characteristics of participants in the Counseling African American to Control Hypertension (CAATCH) Trial are described. CAATCH evaluates the effectiveness of a multi-level, multi-component, evidence-based intervention compared with usual care (UC) in improving BP control among poorly controlled hypertensive African Americans who receive primary care in Community Health Centers (CHCs).

Methods

Participants included 1,039 hypertensive African Americans receiving care in 30 CHCs in the New York Metropolitan area. Baseline data on participant demographic, clinical (e.g., BP, anti-hypertensive medications), psychosocial (e.g., depression, medication adherence, self-efficacy), and behavioral (e.g., exercise, diet) characteristics were gathered through direct observation, chart review, and interview.

Results

The sample was primarily female (71.6%), middle-aged (mean age = 56.9 ± 12.1 years), high school educated (62.4%), low-income (72.4% reporting less than $20,000/year income), and received Medicaid (35.9%) or Medicare (12.6%). Mean systolic and diastolic BP were 150.7 ± 16.7 mm Hg and 91.0 ± 10.6 mm Hg, respectively. Participants were prescribed an average of 2.5 ± 1.9 antihypertensive medications; 54.8% were on a diuretic; 33.8% were on a beta blocker; 41.9% were on calcium channel blockers; 64.8% were on angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs). One-quarter (25.6%) of the sample had resistant hypertension; one-half (55.7%) reported medication non-adherence. Most (79.7%) reported one or more co-morbid medical conditions. The majority of the patients had a Charlson Co-morbidity score ≥ 2. Diabetes mellitus was common (35.8%), and moderate/severe depression was present in 16% of participants. Participants were sedentary (835.3 ± 1,644.2 Kcal burned per week), obese (59.7%), and had poor global physical health, poor eating habits, high health literacy, and good overall mental health.

Conclusions

A majority of patients in the CAATCH trial exhibited adverse lifestyle behaviors, and had significant medical and psychosocial barriers to adequate BP control. Trial outcomes will shed light on the effectiveness of evidence-based interventions for BP control when implemented in real-world medical settings that serve high numbers of low-income hypertensive African-Americans with multiple co-morbidity and significant barriers to behavior change.