Medication Non-Adherence with CHD Outcomes
ABSTRACT & COMMENTARY
Synopsis: As we suspected all along, patients who adhere to their medication regimens have a better prognosis than those who do not.
Source: McDermott, et al. Arch Intern Med 1997;157:1921-29.
Mcdermott and colleagues searched medline under multiple headings for coronary heart disease and then used an OVID search. They identified 289 articles and pulled 179 of them after reviewing the abstracts. Only 21 met their fairly strict inclusion criteria. They did not find any randomized, controlled clinical trials that specifically addressed the issue of medication adherence affecting outcomes in patients with or at risk for coronary heart disease. So, they looked at the study designs, outcome measures, and at "surrogate" markers such as hospital rates, mortality, etc. in coronary heart disease studies. Seven articles clearly showed a benefit of adherence. They then looked at adherence to placebo as an associated factor in reducing morbidity and mortality. They found three studies that showed a beneficial effect.
The authors separately studied the CAST data. (The CAST study proved that in people with asymptomatic PVCs post MI, treatment with encainide or flecainide increased mortality.) They found a higher mortality rate in patients who had taken these drugs than those who were less adherent.
COMMENT BY LEN SCARPINATO, DO
One million MIs make it to medical care in this country each year, and a half million people die each year of congestive heart failure. The therapeutic strategies developed over the last 20-25 years have significantly changed the morbidity and mortality of this disease. We can't easily separate the surgical and angioplastic data from the overall data. But, it should be noted that these have significant benefits.
Medications and lifestyle changes have also had a significant effect on modification of morbidity and mortality, so it's not surprising that McDermott and colleagues would take a look at the rate of adherence to a medication regimen and its affect on morbidity and mortality. The only surprise was that no one had done it sooner.
Even though the 21 studies were not designed to look for this information, they found seven showing that adherence to medication reduced morbidity and mortality-something we've suspected all along. They then really proved it with the higher mortality rate seen in the adherent CAST study participants.
What was most surprising about this review was three studies which showed that adherence to placebo was associated with improved outcome in coronary heart disease. Therefore, patients who adhere to their medication regimens might have a protective effect, and this might result in a better prognosis.
This is something I can tell my patients about. I'm sure they don't want to hear, "If you do what I say, you will live." I think any busy clinician will need to share with their patients in a less pedagogic way that adhering to regimens will help their prognosis. (Dr. Scarpinato is Program Director, Racine Family Practice Residency, Racine, WI.)