Improving Medication Adherence Keep Your Eyes on

Authors: Zachary A Marcum Walid F Gellad

Publish Date: 2016/11/15

Volume: 32, Issue: 3, Pages: 236-237

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Abstract

Medication adherence is a set of complex health behaviors that challenges patients of all ages and health conditions Researchers have spent decades trying to improve medication adherence and yet these interventions have been wrought with limitations and sobering findings The most recent Cochrane systematic review of the impact of adherence interventions found that effects were inconsistent across studies and that only a small number of interventions led to a modest improvement in both adherence and clinical outcomes1 The authors concluded that existing adherence interventions “are mostly complex and not very effective”1 In addition the authors recommended that future research include robust study designs of feasible longterm interventions with sufficient study power to detect improvements in patientcentered clinical outcomes1A key issue in implementing any adherence intervention is ensuring valid measurement of adherence Measurement of medication adherence is complex since most measures serve as proxies for medicationtaking behavior2 For example pharmacy claims data are increasingly used for conducting adherence research although the pharmacy claim serves only as a proxy for medication consumption and in reality it is simply measuring refills Other methods for measurement including selfreport pill counts and electronic capture of pill bottle opening also require important assumptions about the relationship between the measure and actual medicationtaking It is further assumed that improving medication adherence will improve process measures such as blood pressure or cholesterol control which will in turn improve the health outcomes of patients including quality of life and mortalityIn this issue of JGIM Reddy and colleagues present findings on the effect of daily pill bottle alarms combined with individual or partner feedback reports on statin medication adherence3 This 3month threearm randomized clinical trial randomized 126 veterans with known coronary artery disease and poor adherence medication possession ratio MPR 80  to one of three groups 1 a control group that received a pillmonitoring device ie a GlowCap® bottle with no alarms or feedback 2 an individual feedback group that received a daily alarm and a weekly medication adherence feedback report and 3 a partner feedback group that received an alarm and a weekly feedback report that was shared with a friend family member or a peer By the end of the 3month intervention statin adherence was significantly higher in both the individual and partner feedback groups compared to the control arm 89  and 86  vs 67  respectively However at 6 months statin adherence did not differ among the groups 60  and 52  vs 54 The study had a number of strengths and unique aspects First the use of a feedback component in the intervention arms was a novel approach The authors were thus able to assess the impact of peer support via social forces or individual feedback on medication adherence behavior above and beyond the reminder effects of the GlowCap® bottle The use of peer support is increasing in behavior change interventions4 and the application to adherence interventions is important and should be further investigated Second the study included only patients who had suboptimal medication adherence at baseline as measured by a 16month statin MPR 80  In other words the study targeted patients who had a documented need for intervention on some level Interventions targeting individuals with medication adherence problems can have modest but significant effects on medicationtaking behavior5 Additional research is needed to further test this and other riskstratification approaches for improving medication adherence and the targeting of interventionsDespite these strengths some limitations deserve mention most notably concerns about adherence measurement The medication adherence measure was the GlowCap® bottle which includes a computer chip in the lid that detects and timestamps when the lid is removed This is similar to the Medication Event Monitoring System MEMS which is considered a “gold standard” measure of medication adherence in trial settings6 However it is important to remember that it is an indirect method of measurement—opening the bottle does not equal taking the statin It is entirely plausible as the authors discuss that patients receiving feedback reports were more likely to open the bottle but no more likely to take the medicationThese concerns are magnified given the lack of change in LDL seen in the intervention groups Despite the positive impact of the intervention on opening the pill bottle it was found to have no significant effect on LDL levels at 6 months In fact the control group had numerically greater absolute LDL reduction 91 mg/dl than those in the individual feedback group 50 mg/dl and the partner feedback group 46 mg/dl It is not clear why this finding occurred It is possible that certain unmeasured behaviors such as diet and/or exercise were different between the control group and interventions arms In addition the null finding on LDL reduction at 6 months may reflect a lack of difference in adherence among the three groups at that time point rather than during the intervention period Without more frequent measures of LDL during the trial it is difficult to interpret the intervention’s impact on this process measureThere is emerging consensus that multiple methods of adherence measurement should be included in studies of adherence interventions with comparison of results across methods7 A review of studies comparing the MEMS with other methods for measuring medication adherence reported that compared to MEMS adherence was overestimated by 17  using selfreport by 8  using pill count and by 6  using rating by a surrogate6 Although selfreported medication adherence may overestimate the degree of adherence it can offer critical insight into patientspecific barriers to medicationtaking8 For example the intervention studied by Reddy et al would likely have a greater impact on patients whose main barrier is forgetting to take their medication than on patients whose main concern is costrelated Thus selfreported adherence data can allow for the delivery of patienttailored interventions Reddy and colleagues measured selfreported statin adherence at baseline using the fouritem Morisky Medication Adherence Scale This information was used as an adjustment variable whereas it could also potentially have been used as an inclusion criterionDespite these limitations the study shines an important light on the continued need for sustainable medication adherence interventions The authors cite previous research suggesting that formation of a habit takes 66 days on average thus their selection of a 3month intervention more than covered this time frame Yet the relatively rapid decline in statin adherence by 6 months suggests that it takes much less time to unlearn a habit Future research should evaluate the use of “booster” interventions to achieve longterm benefits In addition longitudinal followup of adherence is needed in order to understand the longterm impacts of interventions Novel methods such as groupbased trajectory modeling can be used to model the dynamic nature of adherence over time9 Furthermore with an increasing medication burden on patients providers will need to decide which medications to select for monitoring and how best to respond to the information collected10 The use of an electronic monitoring bottle for a statin is one thing—but what about a patient on five medications of critical importance some of which are weekly injections In addition it remains unclear which type of adherence feedback—individual or partner—is most impactful since the two arms showed similar effects on adherence Further research is needed to assess how best to integrate adherence information of all types electronic patientreported claims into clinical practice and into patients’ livesThe authors conclude by asking “whether a continuous intervention that never ends could lead to sustained high levels of adherence” We would argue that high levels of adherence in the absence of improvements in important health outcomes should not be the ultimate goal The current study showed that among a sample of patients with suboptimal adherence MPR 80  the overall mean baseline LDL was 88 mg/dl This suggests that it is possible to achieve low LDL levels with “suboptimal” adherence and argues for the need to better define adherence thresholds that are able to discriminate across important health outcomes Until then the paper by Reddy and colleagues challenges us to “keep our eyes on the prize” of improving medication adherence and health outcomes

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