A Pharmacist Intervention for Monitoring and Treating Hypertension Using Bidirectional Texting

HTN is associated with the greatest attributable risk for mortality among all modifiable risk factors for cardiovascular disease.[1] In 2014, there were approximately 72 million adults (29%) with HTN in the US.[2] Several clinical trials have demonstrated that antihypertensive medications reduce cardiovascular events.[3] For example, even a 5 mm Hg difference in systolic BP (SBP) over 3-5 years can reduce the risk of cardiovascular complications and strokes by 25-30%.[4] Yet, approximately 20% of U.S. adults are unaware of their HTN,[5] and among patients diagnosed with HTN, 47% are uncontrolled.[2] Thus, there is a critical need to effectively treat patients with HTN.

Clinical inertia has been identified as the primary cause for delays in achieving BP control for over 20 years.[6-8] Providers often discount office BP readings that may be falsely elevated due to observer or measurement error and/or the clinical surroundings (e.g., white coat HTN).[9-11] Patients are often seen only once or twice a year which further delays BP control. Furthermore,[8, 12] BP goals are achieved in only 49% of the patients who take anti-hypertensive medications.[5] New approaches for acquiring more BP readings are also needed to better monitor and titrate treatment because a significant proportion of patients on therapy are not adequately controlled despite frequent physician visits.

Home BP measurements, (i.e., having patients take their BP at home), can facilitate the more timely diagnosis of HTN by reducing diagnostic uncertainty. In fact, home measurements are better prognostic indicators of stroke and cardiovascular mortality than clinic measurements,[13-15] are more closely correlated with end-organ damage from HTN than clinic measurements,[16, 17] are cost effective and well-tolerated by patients,[18] and generate BP readings that are at least as reproducible as clinic readings.[19] Home BP measurements, if available, may help physicians overcome barriers related to clinical inertia.[20] However, the data must be followed by action. The researchers have pioneered physician-pharmacist collaborative management (PPCM) that has been shown to decrease clinical inertia and improve BP control.[21, 22] Pharmacists have been embedded within the medical office to perform BP management. The pharmacists are able to assess patients' needs and provide recommendations to physicians regarding treatment changes, providing patients with timely therapy adjustments.[23] However, many medical office leaders are unable to hire clinical pharmacists due to limited resources. Therefore, a "virtual", remote clinical pharmacy service has been developed.[24] Pharmacists were able to obtain electronic medical record (EMR) access at all intervention offices for private physician offices throughout Iowa. While the physicians accepted 95% of the pharmacists' recommendations, the effect on improving BP was modest (manuscript under review). Adding the proposed texting platform with home BP monitoring should markedly improve the potency of our remote, telepharmacy intervention.

This trial exhibits clinical equipoise because, although it is known that texting is an efficient method for obtaining home BP measurements, and that pharmacist interventions to improve BP are cost-effective, it is not known if combining these two interventions will also be cost effective. There are four reasons why this study might not be successful. First, while meta-analyses have found significantly improved BP with pharmacist interventions some studies were not successful.[25] Second, more data does not necessarily mean better data: patients could report false values, BP could be abnormally low or high during the measurement period, or the data could be ignored. Third, even better data might not lead to better outcomes: data could be ignored by pharmacists, physicians or patients; pharmacists' recommendations could be ignored by physicians or patients. Fourth, even if the study is effective at improving subject outcomes, it might not be cost effective. Texting might not save as much time as hypothesized. Thus, further research is needed to address these gaps in knowledge.

There is a critical need for an easy-to-use, cost-effective, mobile health (m-health) approach to assist patients and healthcare providers with screening, diagnosis, and monitoring of HTN. Small medical offices and those located in poor or rural areas are unable to operationalize team-based care with pharmacists. The researchers have overcome this barrier with the use of a remote clinical pharmacy services. Coronary heart disease deaths could be reduced by 15-20% and stroke deaths by 20-30% if this intervention effectively improves BP and is implemented more widely in primary care offices.

The goal of this proposal is to evaluate whether a scalable, short messaging service (SMS) approach combined with a pharmacist-based intervention improves BP management cost effectively. To achieve this objective, the following specific aims are proposed:

• Determine if mean BP 12 months after the intervention decreases more for the intervention group than the control group. The working hypothesis is that those in the pharmacist-intervention group will achieve larger BP decreases than those in the control group.
• Determine if the intervention leads to more intensification of therapy than in the control group. The working hypothesis is that subjects in the pharmacist-intervention group will have more treatment changes than those in the control group.
• Determine the cost effectiveness of the intervention. The working hypothesis is that the intervention will be cost effective when compared to the control group.

Inclusion criteria

• Fluent in English or Spanish
• Have a clinic measured blood pressure of > or = 145 mmHg and/or > or = 95 mmHg at two previous clinic visits or one previous clinic visit and on the day of enrollment
• Must be a patient at Family Medicine, River Crossings, Scott Blvd, or Muscatine University of Iowa Clinics
• Live in a zip code that is scored as a 4-10 on the Rural-Urban Commuting Area codes

Exclusion criteria

• Currently pregnant or planning to become pregnant in the next year
• Upper arm circumference greater than 50 cm (20 in)
• Prisoner status
• Unable to provide own informed consent