In 2008, the Declaration of Helsinki stated: “Every clinical trial must be registered in a publicly accessible database before recruitment of the first subject.” This core ethical guidance was updated in 2013 as follows: “Every research study involving human subjects must be registered in a publicly accessible database before recruitment of the first subject.”

Registration of research studies is of great importance for the progress of medical research. There are a number of benefits to registering a study (1). For example, the problem of publication bias, whereby studies are performed but not reported, can be more accurately identified and dissuaded. Chapman and colleagues found that one in five surgical randomized controlled trials (RCT) are discontinued early, and one in three remains unpublished 2 years after their conclusion (2). This information is only available due to RCT registration. Another benefit of registering a study protocol, prior to conducting research, is the possibility to pre-specify research questions and outcomes, allowing peer-reviewers and readers to compare these to the published results. This is critical, as demonstrated by Page and colleagues, who identified that a striking 38% of systematic reviews have discrepancy in outcome reporting between protocols and published material (3). Moreover, registration of studies reduces duplication of work, a key source of waste in biomedical research (4).

The registration of clinical trials has been the focus of significant attention. However, while clinical trial registration has improved with time, there has been little improvement in observational studies, despite these making up a growing portion of the research landscape (5). It is estimated that only 10% of observational studies are registered at present on existing registries, and we have argued the need for a new registry. Many registries do not allow retrospective registration, have cost and time implications, and there is often a significant bureaucratic process to register studies (6). As a result, the Research Registry^® (www.researchregistry.com) was launched in February 2015.

The Research Registry^® is funded through the International Journal of Surgery (IJS) Publishing Group, is free for all users to register and is open access. It enables free registration of any research study involving human participants, it takes a few minutes to register and allows prospective and retrospective registration. Researchers get immediate visibility of their registration, and a retrospective data curation process has been developed to remove or modify inappropriate registration (Figure 1). Data collected is in line with the World Health Organization (WHO) dataset for trial registration, and we have integrated elements of key reporting guidelines into the registration forms (7). Modifications to the registry have occurred following usability studies (Figure 2). This paper describes the first 500 registrations to the Research Registry^®.

Over the study period, the Research Registry^® has received registrations from over 57 countries, accounting for over 1.77 million patients, who were otherwise in unregistered studies. Registrations per month gradually increased over the study period, with the exception of August. Objective quality indicators have improved over the course of the first 500 registrations.

The highest number of registrations was received from Turkey, China, and the UK. This reflects in part submissions to two journals, IJS and Annals of Medicine and Surgery (AMS), where registration is mandatory promoting the Research Registry^® as a venue for registration. Concerns were initially raised as to whether clinicians would be willing to register their study as a necessary step during the submission process. This concern was unfounded and authors have engaged well with the process, with no drop in the number of manuscripts being received at IJS or AMS. The number of submissions deleted for being incorrectly registered (n = 80) was mostly case reports. The IDEAL framework to improve the quality of surgical research encourages the registration of first-in-man case reports (9). These should reflect the first time a particular technique is utilized clinically; however, some authors incorrectly register a normal case report with Research Registry^®.

We have observed a gradual increase in registrations per month, from launch in February 2015, to the end of the study period in October 2015, with the exception of August. This is likely due to the reduced number of papers submitted for publication during August and, therefore, less authors directed to the registry. During the study period, over 1.77 million patients were included in registered studies and prior to the launch of the Research Registry^®, many of these studies would not have had a venue of registration. The breadth of countries from which registrations have been received demonstrates the global impact of the Research Registry^® and the breadth of research registration that can be achieved.

It has been estimated that 10% of all observational studies are registered at present. When establishing the Research Registry^®, observational studies were a key focus and this is evidenced in our study breakdown. Over 37% of the registrations during the study period were retrospective cohort studies – studies that previously would have limited options for registration, and if conducted retrospectively, no venue of registration, prior to the launch of the Research Registry^®. Given other registries have found the registration of observational studies challenging, our example of utilizing a journal to boost compliance may be a way forward to improve registration of such studies. The registry has evolved from its surgical roots and recent registrations include an intervention to improve nutritional intake; the investigation of physical activity in women who have had treatment for breast cancer (10) and a pilot study of tremor disruption in Parkinson’s disease (11). Through an agile and iterative approach, new features have been added. These include unique features, such as the ability to upload multimedia to demonstrate interventions, for example, videos of surgical procedures. In September 2015, we added the function to deposit data and results, as well as the ability to update entries. We have also integrated key reporting criteria from STROBE, CONSORT, and PRISMA into our registration forms.

This analysis has a number of limitations, it is limited to a solitary database and we have had a number of challenges, which are similar to other established registries (12). Initially, we had difficulty with inappropriately filled fields in registrations and this reflects the poor quality score initially (Figure 6). This was improved with the combination of mandatory fields and careful data curation. Over time, the registration form has been improved both with formal reviews of the database, and with suggestions from data curators as they review registrations on a weekly basis. We have also experienced technical difficulties, such as the “search the database” function initially using a Google-based search, which was prevented by a national firewall in China. This was rectified by using a non-Google search facility and this aspect of the site has been functioning well in China since July 2015, and during the study period, China provided over 10% of registrations (13).

The Research Registry^® has established itself as a new registry with a clear focus on areas not well represented in existing registries, such as observational studies and those registering retrospectively. Going forward, our plan is to continue developing the platform in line with user and data curator feedback and usability studies. We also aim to establish ourselves as a novel registry, addressing the unmet demands of existing registries to include other study types. Ultimately, we will use this registry to improve compliance with the Declaration of Helsinki 2013.

All authors contributed substantially to the implementation of the study. Specifically, RA was involved in the conception and design of the study. RA, AF, CL, YA, HS, KK, DJ and MA were involved in data acquisition and analysis. RA, AF, CL, PM and DO were involved in data interpretation. Subsequently, RA wrote the first draft, and all authors were then involved in the critical revision and approval of the manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.