By Frannie Raede, MPH, PhD, program manager, commercial development, Pillo Health.
In the U.S., 25% to 50% of all adults fail to take their prescribed medications on time, contributing to poor health outcomes, over-utilization of healthcare services, and significant cost increases. Failing to follow prescribed treatment regimens can have tragic consequences for patients and their families. One study estimates that medication non-adherence causes approximately 125,000 deaths and 10% of hospitalizations annually, and costs the U.S. healthcare system up to $289 billion each year.
Forgetfulness is the primary cause of non-adherence, but there are many other reasons why a patient doesn’t follow a treatment protocol, such as carelessness, fear, supply, cost, lack of information, or not understanding instructions.
Medication non-adherence is too costly to ignore, both in terms of the price to our healthcare system and the overall health and wellbeing of our nation. As the U.S. population ages, the problem will become more acute, with a greater number of older adults battling chronic diseases and conditions.
So, what can be done to reverse the trend?
Current adherence measurements do not paint a clear picture of medication habits, which can impact progress (or lack thereof) relayed between a patient and their provider.
The most frequently used measure of adherence is the Medication Possession Ratio (MPR), where an 80% MPR is considered passing. This is defined as the number of days in supply period, over the difference between the first and last fill dates. MPR ranges from 0 to 1, with 1 representing full adherence. The possession ratio is equal to the total day’s supply fill in a period, divided by the number of days in a period. This ratio is then multiplied by 100 to obtain the percentage of possession.
In theory, an 80% MPR means a patient is taking most of the medication they are prescribed during a certain time frame, but this measurement is not precise. The calculations are usually based on insurance claims data, and therefore do not account for the use of free samples or regimen changes. They also do not provide information beyond possession—for instance, if the medication was taken, if the correct dose was used, or if it was taken at the right time.
These measurements often assume that patients are taking their medications correctly just because they picked them up from the pharmacy. To provide optimal care, healthcare providers need to better understand their patients’ medication behaviors so they can track progress and intervene when necessary, especially in cases where it’s essential a medication is taken correctly to protect a patient’s health.