Revisiting the Polypill: Does it Improve Adherence and Reduce Cardiovascular Risk?

Print

Written By

Nick Messinger, PharmD, BCPS
Kelly Epplen, PharmD, BCACP

Reviewed By

Patricia A. Ross, Pharm.D., BCPS, BCACP
Maria Pruchnicki, Pharm.D., BCPS

Citation

Thom S, Poulter N, Field J, et al. Effects of a Fixed-Dose Combination Strategy on Adherence and Risk Factors in Patient With or at High Risk of CVD: The UMPIRE Randomized Clinical Trial. JAMA 2013;310:918-929

We’ve all encountered patients who’ve had difficulty taking their medications as prescribed.  Many of our patients don’t achieve the recommended treatment goals or derive much benefit their medications.  There are many reasons why patients don’t take their medications in an ideal manner — including cost barriers, unpleasant side effects, treatment complexity, and forgetfulness.  

Pharmacists are often the health care professionals charged with improving medication adherence, working to simplify medication regimens and optimize therapy. What if a patient could take one tablet to treat multiple health conditions?  And what if that pill contained all the guideline recommended drugs?  Would it improve adherence?  Would more patients achieve the therapeutic goals?

Adherence to recommended preventative therapies is low among patients with cardiovascular disease (CVD).1  In light of this well recognized problem, the World Health Organization (WHO) recommended in 2002 that fixed-dose combination (FDC) drug therapy formulations be developed and evaluated with the goal of overcoming poor adherence and inadequate dosing.2

In 2003, a polypill comprised of six components – a fixed-dose of a statin, three antihypertensive agents, folic acid, and aspirin - was first described.  It was claimed that such a pill could reduce the risk of cardiovascular events — including ischemic heart disease and strokes — by 80%.  Moreover, the polypill approach would (hopefully) result in fewer adverse events when compared to treatment strategies that required dose titration of multiple products.3   The UMPIRE (Use of a Multi-drug Pill in Reducing Cardiovascular Events) trial was designed to formally test the notion that a FDC product would significantly improve medication adherence and thereby reduce cardiovascular risk.

The UMPIRE study was a randomized, open-label, blinded-end-point clinical trial comparing FDC-based therapy to usual care in patients with established CVD or who’s calculated 5-year CVD risk was 15% or greater. This multisite study was performed in India, England, Ireland, and the Netherlands. The primary objective was to assess whether an FDC product compared with usual care improves medication adherence, lowers systolic blood pressure (SBP), and reduces low-density lipoprotein cholesterol (LDL-C). This is the first randomized, controlled trial to compare the long-term use of an FDC product with usual care in patients with CVD.

A total of 2,004 patients were randomized in a 1:1 ratio. Those randomized to usual care continued to receive standard treatments from their primary care physician. Those randomized to FDC therapy were prescribed 1 of 2 FDC formulations chosen by the trial physician. The FDC was taken once daily and was dispensed free of charge. Participants in the usual care group acquired their medications subject to local payments or exemptions.

FDC Forumation 1

FDC Forumation 2

Aspirin 75 mg

Simvastatin 40 mg

Lisinopril 10 mg

Atenolol 50 mg

Aspirin 75 mg

Simvastatin 40 mg

Lisinopril 10 mg

Hydrochlorothiazide 12.5 mg

 

Patients attended clinic visits at randomization, 12 months, and at the end of the study. Telephone or clinic visits were conducted at 1 month, 6 months, and 18 months. Adherence was self-reported and defined as taking the medication for at least 4 days during the week preceding the visit.

Outcomes

Fixed-Dose Combination

(n = 1002)

Usual Care

(n = 1002)

Treatment Effect (95% CI)

P Value

Primary End Points

Adherence, No./ total (%)

  829/961 (86)

  621/960 (65)

  1.33
  (1.26 to 1.41)

  <.001

Systolic blood pressure, mmHg

  129.2
  (128.1-130.2)

  131.7
  (130.7-132.8)

  -2.6
  (-4.0 to -1.1)

  <.001

LDL-C, mg/dL

  84.2
  (82.5-85.8)

  88.4
  (86.7-90.0)

  -4.2
  (-6.6 to -1.9)

  <.001

 

These results are encouraging and favored the FDC group but there were several potential study limitations that the authors acknowledge.  First, the sample population (80% male and 50% recruited from India) may not be representative of the general population.  Second, the FDC formulations were provided to participants free of charge (this was not the case in the usual care group) and this could have impacted adherence rates.  And third, the study did not measure cardiovascular events, only surrogate markers of cardiovascular risk.  Only 85 cardiovascular events occurred during the trial and the study was not sufficiently powered to detect differences between the two treatment strategies.

While statistically significant differences were seen in all three primary end points, one has to question the clinical importance of these findings.  Adherence was defined as taking the prescribed medications for at least 4 days during the week preceding the visit.  Thus, an "adherent" patient could have been taking only 57% of the prescribed dose (in the week preceding the visit)!  Moreover, self-reported medication taking behaviors are influenced by social desirability bias as well as inaccurate patient recall. Electronic prescription refill data is one of the most frequently used methods for measuring adherence and patients who fill their medications in a timely manner 80% of the time are generally categorized as adherent.4  Thus, this study failed to implement rigorous methods for measuring medication adherence and it is unknown what percentage of the participants took >80% of their prescribed doses.  In addition, those randomized to FDC therapy were provided medication at no cost and it is well documented that patients' out-of-pocket cost for medication significantly influences adherence rates.  Were the observed improvements in medication adherence in the FDC group due to regimen simplification?  Or lower out-of-pocket cost?

Before we routinely use FDC formulations in practice, clearly more questions need to be answered. What happens when patients need a dose adjustment to one or more of the FDC components? If a FDC had four medications, each with two dose options, 16 different dose combinations would be necessary.  This would likely only increase patient (and prescriber) confusion and errors.  What happens when a patient experiences an adverse effect? How do you know which medication caused that adverse effect?  The FDC concept has perhaps more appeal now that we’ve eliminated LDL-C treatment targets but titrating medications to achieve blood pressure targets will likely remain a standard of care for the foreseeable future.

The UMPIRE trial leaves us with more questions than answers.  The results do not provide us with compelling evidence that FDC products improve adherence.  The root cause of poor medication adherence in most cases probably isn’t regimen complexity (e.g. multiple pills).  Although the primary outcomes of the trial were generally positive, we don’t know if this treatment strategy will reduce cardiovascular events.  While treatment simplification remains a potentially attractive strategy, larger studies are needed to assess the impact of FDC on cardiovascular outcomes.  What do you think?  Is the polypill strategy a credible approach worth continued study … or should we use our time and money to explore other approaches?

Comments

1

Thank you for this well-written commentary. I completely agree that root causes of poor medication adherence isn't necessarily based only on number of pills a patient has to take. All of the medications included in the polypill are once daily. The World Health Organization identifies dosing schedules and food restrictions or requirements as having more pervasive influences on adherence than actual number of pills. However, based on the results of this trial, it looks like the number of pills could play a significant role. It looks like more studies need to be done. I think culture also plays a huge role in adherence, and this study included two very different populations with very different cultures. Could the cultures of the populations have influenced the results?