A review of interventions ≥ 6 months by pharmacists on adherence to medicines in cardiovascular disease: Characteristics of what works and what doesn't.

BACKGROUND

Nonadherence to cardiovascular medicines occurs in 60% of subjects with chronic cardiovascular disease and leads to poor outcomes. In an attempt to improve adherence and cardiovascular outcomes, interventions are often used. Interventions may involve a pharmacist, but it is not always clear whether these are effective.

OBJECTIVES

The primary objective of this review is to determine whether interventions by pharmacists, alone, discussing adherence to medicines, improve adherence to medicines for cardiovascular disease. Subsequently, the review links the characteristics of the individual studies with effectiveness or lack of effect. The second objective of this review is to consider whether any improvement in adherence with interventions by pharmacist is associated with better clinical outcomes.

METHODS

A literature search of PubMed and CINAHL for 'pharmacist', 'medicine' with 'adherence' or 'compliance' or 'persistence' was undertaken. To be included in this review, papers had to be of a pharmacist working alone and in person in an intervention of subjects with hypertension, hyperlipidemia (prior to or after a coronary artery event) or heart failure. The paper had to be published in a peer review journal, with a measure of adherence to medicines. The effectiveness of the intervention had to be evaluated after ≥6 months.

RESULTS

Only 3 out of 8 interventions by pharmacists in hypertension, and 5 out of 12 interventions in subjects with hyperlipidemia led to improved adherence to medicines. In contrast, all 6 interventions by a pharmacist in subjects with heart failure were successful in improving adherence. One characteristic of successful interventions by pharmacists to improve adherence to cardiovascular medicines is that they must be more than brief/single interventions. A second characteristic is that the intervention should not involve subjects who are already highly adherent, as it is unlikely adherence can be improved in this population. Only 2 of 3 successful interventions in hypertension were associated with small reductions in blood pressure, and only one intervention in hyperlipidemia was shown to decrease LDL-cholesterol to a small extent. In subjects with heart failure, 5 of the 6 successful studies of the successful interventions by pharmacists to increase adherence also showed improved clinical outcomes.

CONCLUSIONS

When planning an intervention to improve adherence to medicines and cardiovascular outcomes in subjects with hypertension or hyperlipidemic, by a pharmacist alone, or as part of a multi-faceted interventions, it is essential to use an intervention that has been shown to be effective, as most interventions are not effective at improving adherence or only improve adherence and clinical outcomes to a small extent. In heart failure, there is well documented evidence of interventions by pharmacists that do improve clinical outcomes, which should be adopted widely.