Collaborative care model for hypertension

INTRODUCTION

Clinical inertia has been a major topic in hypertension management since at least 1998 when Berlowitz and colleagues1 reported their evaluation of 800 patients. While about 40% of their patients had blood pressure (BP) values >160/90 mm Hg, therapy was increased only 6.7% of the time despite an average of six visits per year. BP control has improved substantially over the past 20 years to 54% of all hypertension cases in the United States. Clearly, BP control is still inadequate, especially in patients from racial minority groups.2, 3

Team‐based care including the physician/pharmacist collaborative model (PPCM) has been one of the most effective strategies to improve BP.4, 5, 6 PPCM has also been shown to improve BP in racial minority groups but there continues to be disparities in BP control.7 However, additional evidence for PPCM is needed in racial minorities and in those with socioeconomic disadvantage.

A likely reason that PPCM improves BP compared with usual care is that studies of pharmacist management have almost always found more intensification of medications in the intervention group compared with usual care.8, 9 Additionally, PPCM has typically been shown to intensify therapy at the initial visit and at least monthly unless there were extenuating circumstances to prevent such intensification.8

There is evidence from the VALUE (Valsartan Antihypertensive Long‐Term Use Evaluation) trial that achieving BP control within the first few months of an intervention reduced cardiovascular events.10 While there is some information about how quickly BP control is achieved with PPCM,8, 11 the evidence has been limited. The article by Dixon and colleagues12 in this issue of the Journal provides an important contribution to this field. These authors studied 377 uninsured patients with a median time to BP goal of 36 days in the pharmacist intervention group compared with 259 days in the usual care group (P < .001). BP control achieved nearly 8 months sooner, and in significantly more patients (81% vs 44%, P < .001), in the intervention group compared with the usual care group. This BP control rate is one of the highest seen with PPCM, which is impressive since this was achieved in an uninsured, predominantly black population. The mean number of medication changes was greater with the intervention than usual care (1.9 vs 1.1, P < .001), which is consistent with other studies.8, 9, 11

There are some concerns related to this study, however, including that it was a retrospective analysis. BP was carefully measured several times at each visit in the pharmacist group, which is a standard approach with PPCM. BP may not have been measured with as much diligence in the usual care group and errors in BP measurement result in higher BP readings. However, if there were higher readings in the usual care group, it should have resulted in more action and drug intensification, which was not the case. Providers may not have trusted the BP values, but repeat measurements should have been performed to address the high BP in the usual care group.

Another limitation of this study was that there were imbalances between groups at baseline. The usual care group was older, more likely had diabetes mellitus and coronary artery disease, took more antihypertensive medications, had higher systolic BP, and were less likely to be women. To their credit, the authors conducted sensitivity analyses, including case matching, to assess whether the effect was robust and the findings were similar and still significant.

An important point needs to be made about the patients who participated in the study by Dixon and colleagues. BP control rates in many office practices now exceed 75%. The patients in this trial would be that subset of the practice who have not achieved BP control, perhaps for long periods of time. This study confirms that patients with treatment resistance or difficult to control BP can have improvements with PPCM.13

How should practices considering PPCM operationalize the service? The proposed PPCM in our trials involved pharmacists embedded within the office, and the intervention included: (1) a medication history; (2) an assessment of knowledge of BP medications, dosages and timing, and potential side effects; and (3) other barriers to BP control (eg, side effects and nonadherence). The pharmacist in our model created a care plan with recommendations for the physician to adjust therapy.8, 11, 14, 15 The model recommended a telephone call at 2 weeks, structured face‐to‐face visits at baseline, at 1, 2, 4, 6, and 8 months, and additional visits if BP remained uncontrolled. Patients with uncontrolled BP were rescheduled for follow‐up in 1 to 4 weeks depending on the severity of hypertension. Some patients are knowledgeable and a few dosage titrations can be performed over the telephone to reduce the number of some office visits. The need for visits depends on the BP, risk factors, and suspected reasons for poor BP control. In many primary care offices, the patient is referred back to the physician or nurse once the BP is controlled. If BP control is lost, the patient may be referred back to the pharmacist. Other strategies in the PPCM model can be found elsewhere.16

The medical office personnel need a protocol and strategy to contact patients who fail to make follow‐up appointments and reschedule visits. Multiple no‐show visits is a warning sign for poor adherence and poor BP control. Office staff and the pharmacist may need to engage the patient's caregiver, if there is one, to reinforce social support to improve lifestyle modification, medication adherence, and adherence to office visits.

The article by Dixon and colleagues adds further evidence that pharmacists are critical members of care teams. Each medical office will have unique cultures, communication styles, and populations. Medical providers and administrators in each office will need to determine the best strategies to integrate nurses and pharmacists into the care team. Accountable Care Organizations, the Centers for Medicare and Medicaid Services, and insurance companies are increasingly establishing goals for improved quality outcomes including better BP control. Team‐based care will be critical for medical offices to achieve benchmarks.

Carter BL. Collaborative care model for hypertension. J Clin Hypertens. 2018;20:96–97. 10.1111/jch.13142