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How to Select the Best Sites for Your Clinical Trial

The outcomes of a clinical trial are dependent on the clinicians who will enroll, treat and evaluate participants, and so selecting the right trial sites is paramount to a successful clinical trial, and something that must be carefully considered.

Careful consideration of appropriate sites is essential for several ethical, scientific and operational reasons. 86% of clinical trials will experience delays which are a huge drain on resources. A leading cause of this is failure to recruit patients in sufficient numbers, within expected timeframes. Inadequate sites ultimately drain valuable resources through the extra training and visits they require, and the costs incurred by delays. In order to prevent these effects, trial organizers must ensure that potential sites are carefully screened and only those which are equipped and able to recruit patients and collect accurate, high-quality data are eventually selected. This will increase the likelihood of a trial that is both timely and cost-effective.

What Should you Look For?

Most clinical trials organizers are well aware of the dangers of choosing wrongly, but simply do not know what they should look for when evaluating a potential site. Here are a few crucial criteria to consider:

Staff Experience: To ensure protocol compliance, it’s important to be sure that the right staff are available at each site. They should be experienced enough to be familiar with necessary compliance procedures and study conduct. They should also be familiar with trial procedures such as the informed consent process, submissions to ethical and regulatory authorities and contracting.

Site History: The screening of potential sites should always begin with a review of the site’s history. The only way to truly be sure the site can meet the requirements of the trial is to ensure it has previously been involved in a study of similar size or complexity, and successfully so. Recruitment statistics for previous trials, if available, are also a great indicator of expected performance and should be compared to the estimates the site has provided.

Site Knowledge: If a site specializes in the target disease, they are more likely to be successful in recruiting patients and following protocol.

Locality: Travel is often a significant burden on patient recruitment and retention, and a barrier to patient participation. It is important to select sites that are as close as possible to the target population, in order to achieve desired targets for enrollment and retention. This is especially crucial for those studies that require frequent site visits.

Site Capabilities: Any thorough pre-screen of potential sites should be satisfied that the site is equipped to fulfill all the activities specified in the protocol, but it is also important to determine whether they currently possess all the necessary infrastructure themselves or if some equipment needs to be provided. In this case, extra costs may be incurred, and delays will be caused – important considerations when choosing the right site.

Pre-Registered Patients: If a site already has registered patients who meet the study criteria, this could be a significant benefit when it comes to meeting enrollment targets. However, it’s also important to ensure the site is not already involved in other similar studies which may compete for its patients and resources.

Further Tips:


It is important for the design of the study and the protocol synopsis to be clear and finalized before the final selection is made. That ensures that the site selection can be tailored to the demands of the study, and an appropriate selection can be made.


Utilising the networks, experience and expertise of a CRO can undoubtedly help in finding suitable sites and also improve the efficiency of the whole selection process.

Professional Networks:

Using professional networks to gain and share information about sites is a great way to improve site selection through shared experiences.

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