PLAIN LANGUAGE SUMMARY

People at risk or suffering from cardiovascular disease need to be encouraged to take drugs which decrease blood lipids (lipid lowering medication/cholesterol lowering medication).

Lipid lowering medication has been shown to be very effective in the prevention of heart attack and stroke. People can find it difficult to take their medicines as prescribed, and this is thought to be an important factor in treatment failure. Doctors are keen for patients to take their medication at the right dosage and long term. This review of trials reports interventions to improve patients' drug taking behavior (medication adherence). It shows that so far no specific type of intervention has been found to be particularly successful.

Background.

Lipid lowering drugs are still widely underused, despite compelling evidence about their effectiveness in the treatment and prevention of cardiovascular disease. Poor patient adherence to medication regimen is a major factor in the lack of success in treating hyperlipidemia. In this review we focus on interventions, which encourage patients at risk of heart disease or stroke to take lipid lowering medication regularly.

Objectives.

To assess the effect of interventions aiming at improved adherence to lipid lowering drugs, focusing on measures of adherence and clinical outcomes.

Search Strategy.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycInfo and CINAHL. Date of most recent search was in February 2003. No language restrictions were applied.

Selection Criteria.

Randomised controlled trials of adherence-enhancing interventions to lipid lowering medication in adults for both primary and secondary prevention of cardiovascular disease in an ambulatory setting.

Data Collection and Analysis.

Two reviewers extracted data independently and assessed studies according to criteria outlined by the Cochrane Reviewers' Handbook.

Main Results.

The eight studies found contained data on 5943 patients. Interventions could be stratified into four categories: 1. simplification of drug regimen, 2. patient information/education, 3. intensified patient care such as reminding and 4. complex behavioural interventions such as group sessions. Change in adherence ranged from -3% to 25% (decrease in adherence by 3% to increase in adherence by 25%). Three studies reported significantly improved adherence through simplification of drug regimen (category 1), improved patient information/education (category 2) and reminding (category 3). The fact that the successful interventions were evenly spread across the categories does not suggest any advantage of one particular type of intervention. The methodological and analytical quality was generally low and results have to be considered with caution. Combining data was not appropriate due to the substantial heterogeneity between included randomised controlled trials (RCTs).

Authors' Conclusions.

At this stage, no specific intervention aimed at improving adherence to lipid lowering drugs can be recommended. The lack of a gold standard method of measuring adherence is one major barrier in adherence research. More reliable data might be achieved by newer methods of measurement, more consistency in adherence assessment and longer duration of follow-up. Increased patient-centeredness with emphasis on the patient's perspective and shared-decision-making might lead to more conclusive answers when searching for tools to encourage patients to take lipid lowering medication.

Comment.

These are both review articles from The Cochrane Database of Systematic Reviews. I have chosen to write a single comment on these 2 articles for a number of reasons. One reason to select these is that review articles are excellent resources to assist professionals in staying current with particular areas of research. Generally, they are articles that contain the current information on a single topic, for example, as above, with exercise and heart failure or medication compliance. Second, Cochrane reviews are available online at http://www.cochrane.org/index.htm and can be searched in a number of ways. Cochrane is an excellent source for review articles and for updated review articles; there are several other sources as well. Finally, these and other review articles are good resources for more specific articles on particular topics that professionals may be interested in pursuing.

There is one caution, however, with Cochrane and other review sources. The Cochrane reviews are particularly heavily weighted for both research methodology and statistics. However, the main points of these reviews are usually easily understandable and, in fact, always presented (as above) in a "Plain Language Summary."

These particular reviews are pertinent for a number of obvious reasons. Both heart failure and compliance to behavior change (including medication compliance) are clearly important to cardiac rehabilitation professionals and programs. The heart failure review above states that the research is not conclusive, but is positive. The shortcomings of the body of research are presented in an understandable way; thus, the importance of an ongoing trial (the HF-ACTION trial) is underscored, and our ongoing efforts to obtain reimbursement for this diagnosis remain important to patients.

Compliance with behavior change is perhaps the most difficult issue that all programs and professionals face with the long-term efficacy of our programs. This review concludes that no single method is superior, that more research is necessary, and, most importantly, that centering the intervention on the patient and "shared-decision-making" may be most important. The struggles with the behavioral aspects of lifestyle intervention are difficult and we clearly have little understanding of what works, what does not, and how it should be applied to individuals within our programs. All the more reason to continue the search!

JR