Lay Summaries of Clinical Study Results: An Overview

Lay summaries help to provide transparency and understanding of clinical study results to the general public

Benefits of lay summaries and how to write one

The below article was originally published online: 14 June 2019

Amber Barnes1, Susan Patrick © The Author(s) 2019


The European Union Clinical Trials Regulation (EU CTR) 536/2014 includes a requirement for the submission of lay summaries. Study participants, advocacy groups, and, to a lesser extent, the general public have called for greater transparency in their quest for information on clinical studies. As a complement to other forms of clinical study disclosure such as registry postings and scientific publications, lay summaries may aid in the transparency of a sponsor’s clinical study results, thereby promoting trust, partnership, and patient engagement throughout the clinical study process. The data transparency field is changing rapidly; therefore, data owners should strive to stay abreast of the changes and deliver meaningful tools to their study participants and the public. Points to consider when developing lay summaries of clinical study results include regulatory drivers, the target audience, communication of complex data in a lay manner, and efficient processes for the development of lay summaries within one’s company.

Lay summaries help to provide transparency and understanding to the general public

Plain Language Summary

There is a rule in Europe that clinical studies (experiments in humans) must have a summary written in plain language. Summaries written in plain language help people who are not scientists or doctors understand complex medical information. People who participate in clinical studies, and others, may want to know information about clinical study results. Lay summaries are a way to share clinical study results, but they do not replace other ways that information is shared. Lay summary writers must think about how they can help readers understand the information. It is hard to describe the results of clinical studies in a way that everyone can understand. This article gives some ideas to think about when writing lay summaries.

Key Points
Lay summaries of clinical study results are a complement to other forms of clinical study disclosure that aid in the understanding of complex clinical study results.
The initial requirement for lay summaries began as a result of the EU Clinical Trial Regulation; however, evolving regulations and policies around the globe are shaping the future of clinical study disclosure.
Ensuring patient value should be of paramount importance when developing lay summaries.

1. What are Lay Summaries and Why are They Needed?

Lay summaries (also called layperson summaries, plain language summaries, lay language summaries, simple summaries, and trial results summaries) are plain language descriptions of the design and aggregate results of individual clinical studies (Fig.1)

Example of a lay summary

Fig. 1 Excerpted pages from a published lay summary

Lay summaries are one way for industry to provide greater transparency to those interested in learning about clinical study results [2]. These documents are written specifically for study participants and the general public who have an interest in clinical study results, but who may have limited health literacy or scientific expertise. Health literacy is defined as the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions [3]. The goal of a lay summary is to aid study participants and the general public in understanding clinical study results. Not only does this effort help to demystify the clinical study process but it also provides the main results of clinical studies in a manner directed specifically towards people with low health literacy. The target audience is any person interested in research, and, as such, the audience is broad and may include study participants, healthcare professionals, caregivers, and the general public.

Companies providing lay summaries in advance of requirements are communicating respect for the needs and desires of the community

The data transparency field is changing rapidly, with recognition that the desires of patients and the general public may go beyond those driven by regulatory requirements. Although regulatory agencies do not currently require submission of lay summaries, some agencies have provided additional statements on the topic, as summarized below, in preparation for when the regulations come into effect. The commitment of a sponsor company to provide lay summaries in advance of regulatory requirements provides a meaningful way of communicating respect for the needs and desires of the community, particularly study participants.

The push for increased transparency in the clinical study space has presented industry and academia with an interesting choice—to proactively engage or only meet regulatory requirements. Currently, some transparency activities are not required per regulations and are implemented solely based on a company’s own policies on clinical transparency and data sharing. For example, the proactive release of clinical documents and datasets can occur through various mechanisms such as portals (e.g.,, registration and results disclosure (e.g., or posting lay summaries of clinical study results to publicly available websites. Other transparency activities are regulatory driven, such as the release of redacted or anonymized documents for European Medicines Agency (EMA) Policy 0070.

2. What are the Current Regulatory Requirements?

2.1 European Medicines Agency: EU Clinical Trial Regulation 536/2014

The EMA initiated the call for the submission of lay summaries through the European Union Clinical Trials Regulation (EU CTR) 536/2014. Among other elements described in the regulation, sponsors must submit a summary of the results of the clinical study, together with a summary and the Clinical Study Report (CSR), irrespective of the outcome of the study. The summary must be provided in a ‘format understandable to laypersons’, with posting to the portal 1 year after the end of the trial (EoT) for studies in adults, and 6 months after the EoT for studies in the pediatric population, in all the EU languages in which the study was conducted (Fig. 2).

EU Clinical Trial Regulation 536/2014 potential timeline
Fig. 2 EU Clinical Trial Regulation 536/2014potential timeline. EoT end of trial (defined as the last visit of the last participant in all concerned member states, or at a later point in time as defined in the protocol), LS lay summary, Peds pediatric patients, mos months

Once the regulation is in application, all new interventional clinical studies will need to comply; however, the regulation includes three phases of implementation. Assuming the dates currently projected by the EMA, this would provide the following timescale for sponsors to submit lay summaries:

  • Phase 1: A 1-year introductory period where regulations are optional.
  • Phase 2: Spanning the second and third year of the transitory period; the regulation will be mandatory for new studies.
  • Phase 3: After the 3-year transitory period described
    above, the regulation will be mandatory for all studies (both ongoing and new studies).

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