Pharmacy Options Oct 31, 2013

Myth Busting: Pharmacies That Boost Adherence

Patients receiving medication from home delivery pharmacies have higher adherence. Our recent study controlled for possible theories as why this may be.

It's well documented that patients receiving medications through a home delivery pharmacy are more likely to take their medications than patients who use a retail pharmacy. In other words, home delivery is better for medication adherence.

There are several theories about why adherence rates are higher at home delivery pharmacies. Some experts have argued that the 90-day supply through home delivery is inherently better than a 30-day supply through retail because there are fewer opportunities to forget a refill. Other experts have suggested that home delivery is better only in patients who are already engaged in healthy behaviors.
Our latest research show that even controlling for impact of each of these factors, we demonstrated that home delivery still had significantly higher adherence rates – 11% to 19% in the three therapy classes studied – than retail pharmacies.

The study, recently published in the American Journal of Managed Care, busts several myths:

  • MYTH 1: Home delivery does not lead to greater adherence; it is simply because 90-day supplies offer more medications than 30-day supplies.

It's true that patients receiving 90-day supplies (either through retail or home delivery) typically are more adherent to their medications than patients receiving 30-day supplies – most likely because there are fewer opportunities for common behaviors like forgetfulness and procrastination with a 90-day supply. However, study results demonstrate that even when specifically comparing 90-day supply through retail to 90-day supply through home delivery, patients using home delivery are still significantly more likely to adhere to important medications in two of the three therapy classes studied.

  • MYTH 2: People who opt to use home delivery are simply more conscientious about their health, and therefore higher adherence in home delivery is just an artifact of patients’ predisposition to be adherent.

Our study shows that although patients’ predisposition to being healthy is a key contributor to adherence behavior, home delivery is still associated with higher adherence rates after controlling for this effect. We analyzed claims for patients from 12 months prior to the main analysis period to register their previous adherence behavior. As past health behavior has been known to be a good marker for predicting future health behaviors, using a patient's baseline adherence as a control for his predisposition to being adherent in the future helped ensure that the dispensing channel does not get undue credit for health conscious patients. We found patients using home delivery are still much more likely to follow doctors' orders than those using retail pharmacies. To our knowledge, no previously published channel-adherence studies have attempted to control for prior adherence behavior. 

  • MYTH 3: Classifying patients as using one dispensing channel or the other on the basis of simple majority – 50% of the time using one channel – gives credit to home delivery for adherence habits forged in retail pharmacies.

Not true. To control for this, we categorized patients into three categories – home delivery, retail and those who used a combination of home delivery and retail (mixed). Only patients who used one channel or the other for an overwhelming majority of the time – at least 66.7% – were classified as home delivery or retail users. Patients who used home delivery at least two-thirds of the time were still significantly more likely to be adherent than those who used retail.

  • MYTH 4: Even if home delivery pharmacies truly do deliver higher adherence rates, they only work if members are forced to use them.

This is not true. For this study we excluded patients who were required to use home delivery and found that patients who chose to receive medications through home delivery were more adherent than those that opted for a retail pharmacy.

Key Points on Methodology

This study looked at Express Scripts commercial claims data from a nationally representative sample of patients with high blood cholesterol, hypertension and diabetes. 

  • In the U.S., 45% of adults have at least one of the three conditions.

The study timeline included: 

  • An index period in 4Q 2009 where patients to be included in the study were identified
  • A baseline period in 2010, which was used to examine patients' prior adherence behavior
  • A main analysis period in 2011 during which the association between dispensing channel and adherence was analyzed


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