The issue of patient retention in clinical trials

Monday, June 27, 2016

The Pulse on Patient Recruitment by Ashley Tointon

Recent discussions in the clinical trials arena among patient recruitment professionals have centered around accurately defining and understanding the difference between patient retention and patient adherence. Although both are important to the success of a trial, they may fall in distinct work streams that can easily be confused. 

Patient retention is defined as the strategy and tactics designed to keep patients enrolled in clinical trials, and from discontinuing participation and “dropping out.” Patient adherence is defined as the level of compliance a patient has with taking their medication as prescribed. Although different, a non-adherent patient who is involved in a clinical trial may be an increased risk to discontinue their study participation. There are certain responsibilities a study participant may have in addition to adhering to study medication. These responsibilities may include diary completion, dietary restrictions, follow-up phone calls or other study-specific accountabilities.  


How pervasive are problematic patient retention rates in clinical trials? According to Forte Research the average dropout rate across all clinical trials is an alarming 30%. Although it is a patient’s right to drop out from a trial—at any time for any reason—and this is thoroughly explained in the informed consent process, there are definitely some reasons patients cite as to why they discontinue study participation. Inconvenience is a large part of why patients drop out of clinical trials. If the study site is far from a patient’s home or workplace, if there are multiple visits involved and if the scheduling of appointments does not fit within their routine, they may drop out.

There are some proactive things that can be done to make studies more convenient for patients, such as providing parking, flexible hours, transportation or employing home health services to eliminate some study visits. Making sure protocols are written with the patient in mind would be most helpful as well. For example, the number of blood draws in many protocols may be statistically important for a clinical data set, but logistically challenging and overwhelming for the actual patients who have to comply with that requirement.There are many other reasons beside inconvenience that cause patients to drop out of clinical trials. Placebo-controlled trials are particularly vulnerable to retention issues as patients begin to suspect that their condition is not managed better by participating in a clinical trial where placebo is involved.

Patient adherence is another problem altogether. The instances of people who do not take their medication as directed is enormous and a large part of wasted healthcare resources. According to the National Institutes of Health (NIH) the cost of prescription medicine alone in 2010 was $259 billion and according to CNN Money, healthcare spending is expected to grow an average of 5.8 percent per year until 2024. Medications only work if they are taken, and taken as prescribed. This is a huge concern both for the patient’s condition and the residual contribution to rising healthcare costs due to more frequent physician visits, hospitalizations or other costly medical care. Worse yet, 75% of U.S. adults are non-adherent to physician-prescribed treatment regimens in more than one way. The waste generated from non-adherence, according to PubMed, ranges between 25 and 50%. 

Some patients may simply forget while some may not have a clear understanding of the importance of taking medication properly or finishing a trial. These are issues that can be aided by proactively planning strategies to educate patients on the importance of complying with all components of clinical protocol, to include medication instructions along with the value of completing a clinical trial. Text message reminders are one easy way to help patients remember to take medication and to remind them of upcoming study visits.

While there are no easy answers when dealing with both study retention and patient adherence, clinical recruitment specialists who develop strategies and tactics that address the major hurdles patients face to comply with the protocol, educate patients on the expectations and assure their understanding and agreement. They further stress the importance of taking study medication as directed, so as patients are more likely to have both a higher retention rate as well as higher adherence rate. Clinical recruitment specialist should be included as part of the team developing the clinical protocol to provide the patient retention and adherence perspective to help assure that patients are both recruited and retained successfully. 


Ashley Tointon has more than 18 years of patient recruitment and project management experience supporting clinical trials and the pharmaceutical industry. She currently provides recruitment expertise, strategy and leadership as Principal Consultant of Accelerate Clinical Enrollment LLC. Email comments and suggestions to

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