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Adherence and Intensification of Medications: A Population-Based Clinical Pharmacists Implementation Study among Hypertensive Diabetes Patients
Mary Ellen M Heisler, MD MPA
VA Ann Arbor Healthcare System, Ann Arbor, MI
Ann Arbor, MI
Funding Period: July 2007 - April 2011
Good blood pressure (BP) control is an especially important clinical outcome in diabetes. Patients who have poorly controlled hypertension often have either medication adherence problems or other issues contributing to lack of appropriate provider intensification of their medications. We designed a targeted and intensive pharmacist-based intervention, using the best evidence from efficacy trials, to improve BP control among diabetes patients with persistent hypertension.
The primary aim of this study was to evaluate the effects of the intervention on blood pressure. Secondary aims included: 1) assessing the effects of the intervention on glycemic and lipid control; and 2) evaluating the level of attainment of intervention implementation, examining the process of intervention implementation, and determining the potential for sustainability.
In this prospective, cluster-randomized implementation study sixteen primary care teams, in five medical centers (3 VA; 2 KP), were randomized to the AIM intervention or to usual care. Clinical pharmacists trained in motivational interviewing and supported by clinical information systems proactively reached out to eligible patients (defined as diabetic patients with persistent poor blood pressure control and poor medication refill adherence or insufficient medication intensification) and provided adherence counseling, titration of medications, or both during a 14-month intervention period (July 2008-August 2009). Control team patients had access to usual care management from nurses and clinical pharmacists.
The primary outcome was the relative change in systolic blood pressure (SBP) measurements between the 6-months preceding and the 6-months following the 14-month intervention period, examining this change for all eligible control and intervention subjects regardless of participation in the intervention (intention to treat analysis). Shorter-term changes in SBP were examined as a secondary outcome. SBP measures came from the usual clinical care electronic databases (excluding all BPs measured by the AIM pharmacists). The analysis was done with a 3-level multiple linear regression, with SBP measurements nested within subject within team to appropriately account for the clustering of patients within teams and the precision of blood pressure measurement given differing numbers of blood pressure measurements per subject.
Additionally, a formative evaluation was conducted to evaluate the level of attainment of intervention implementation, examine the process of intervention implementation, and determine the potential for sustainability.
Among 31,257 diabetic patients in the 5 sites, only 15% (2,319 in the intervention group; 2,303 in the usual care group) met the eligibility criteria. We compared changes in SBP among eligible patients on the control teams and the 1,797 patients on the intervention teams who the AIM pharmacists contacted or attempted to contact (53% of these had at least one intervention encounter). In our primary analysis, the intervention group SBP change from 6-months prior to vs. 6-months after the 14-month intervention was approximately the same as the control group, declining 8.9 mm Hg in the intervention compared to 9.0 mm Hg in the control group. SBP lowering occurred more rapidly among eligible intervention team patients, with mean SBPs 2.4 mm Hg lower after the intervention than those achieved by eligible control patients (p<.001). We did not find any differences in lipid or glycemic control between the intervention and control groups.
The formative evaluation showed that the level of attainment of the intervention was acceptable (e.g., 90% of essential elements were documented in the IT application used by the pharmacists, pharmacists reached proficiency in MI). Minor site-specific tailoring was required during the intervention. The prospects for sustainability are limited, as the intervention resulted in modest benefits. Some components of the intervention, however, have been sustained in modified form and are influencing care delivery at the study sites (e.g., AIM pharmacists were hired as permanent employees at sites and continue to use MI, other VA initiatives are incorporating MI).
The study findings reinforce the importance of carefully testing the effectiveness of interventions with known efficacy in real-world practice before broad implementation. Our study suggests that in high performing health-care systems (like VA and KP) that have already achieved high levels of blood pressure control (approx. 80%), a state of the art intensive pharmacist-led program such as that evaluated here does not provide sustained incremental benefit for the small target group of "fall-outs". The systems that have been put into place already to achieve the impressive rates of blood pressure control may be demonstrating best achievable practices.
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DRA: Diabetes and Other Endocrine Disorders
DRE: Treatment - Observational, Treatment - Efficacy/Effectiveness Clinical Trial
Keywords: Diabetes, Hypertension, Pharmaceuticals
MeSH Terms: none