The survey link was sent to the active email accounts of 1,047 registered user accounts of which 48 were duplicate accounts for the same named contact and as the questionnaire blocked more than one response per computer, we anticipated a maximum return of 999. A total of 232 responses were received, giving a response rate of 23%. None of the questions were compulsory so the number of responses per question varied.
Overall, the feedback on functionality and ease of use was positive. Brief details are given here with additional information provided in Additional file
2. The joining process and navigation around the registration form were considered to be easy or very easy by 99% of users. Supporting materials, including guidance, references and links to other resources, were found to be helpful or very helpful by 67% of respondents; most people (177 (82%)) found all or most of the registration fields of relevance to the systematic review protocols they had registered or were likely to register.
The majority of respondents, 176 (81%) had a written protocol for their systematic review before completing the PROSPERO registration form. Of those who did not have a protocol; 42 (19%) used their grant proposal or detailed project description to complete the registration form. In two cases, the protocol was designed using the headings from PROSPERO. Others found that completing the registration form helped improve their protocol by making them formalise less detailed areas. One registrant had split the protocol for a review looking at two different clinical areas, funded by a single grant.
Completing the registration form
Most submissions took between 30 minutes and 1 hour to complete; 136 (79%) indicated they completed the registration form in 60 minutes or less. The majority, 167 (87%), considered the time taken to be about right; 24 (12%) felt it took too long and 2 (1%) too short a time. Comments received indicated that for those with a prepared protocol, completion was quick. Where protocols were in a different format completion took longer, but there appeared to be a willingness to change to the PROSPERO format. Some used the registration form as a guide for ‘tidying up’ the protocol and some prepared responses to each of the questions in a separate document, and circulated it to colleagues to ensure it was ready before cutting and pasting into the PROSPERO form. Some felt the time taken depended on the subject of the review, and that completion of the form would become easier with familiarity.
A guideline developer with multiple reviews for each guideline indicated that they were weighing the time/resources involved against the benefits of registration.
Overall, there appeared to be recognition that for registration to be of good quality it needs an adequate amount of time to be spent on it and the protocol, and that the process helped.
Respondents reported that they were ‘impressed with the turnaround time and the very friendly contact’ and the majority rated the turn round time for a decision (121 (97%)) and information provided in correspondence (99 (79%)) as excellent or very good.
All seven respondents who had had a submission rejected said the reason for rejection was made clear in the email response. However, two said eligibility was not clear in the information given in the form or on the PROSPERO website; two did not look at the time; and three said that on reflection the information was available at the time. One commented that the inclusion criteria could be more obvious to site users.
PROSPERO compared favourably with previous experiences of trials registration, being ‘on a par’ with the ANZCTR (Australian New Zealand Clinical Trials Registry) and ‘much easier’ than clinicaltrials.gov. The absence of registration fees was identified as helpful. Although a number of respondents felt that PROSPERO was easier, quicker and more flexible than registering a Cochrane Review protocol, the majority acknowledged that the systems are different, particularly in the editorial process.
Overall, 189 (86%) respondents rated their experience of registering their review protocol details on PROSPERO as excellent or good; 21 (10%) as adequate and 9 (4%) as poor. None of those who rated their experience as poor had actually submitted a form, although eight said they are likely to do so in the future and gave positive responses to other questions in the survey. Thirty-two people had two records published, five had three records published, two had four records published, and one individual had seven reviews registered.
Positive comments were made about the information provided in correspondence, how useful the process was for learning how to write a complete protocol for a systematic review, and satisfaction in knowing your work is out in the public domain. The only negative comments were about email enquiries made which had received no response. This flagged a problem in the system which we believe has subsequently been fixed.
Nearly all the respondents who had created a record or previously submitted a registration form said they were very likely or likely to register a systematic review protocol in the future, 207 (94%). However, three (1%) said they would only register if the commissioner of a review made it a requirement. Comments were received from one person who registered only because it was required, one who was required to register but would have done so any way and one who would do so if the commissioners/funders allow it.
General feedback
Survey respondents were invited to make additional further comments or suggestions. Some reiterated their support for the planned broadening of scope for inclusion of systematic reviews beyond those of effects. Others asked for more flexibility within the form while still acknowledging the good intent. Suggestions for improvements to the search facility in the public interface were also given.
The majority of comments supported the principle of protocol registration and PROSPERO. Comments ranged from ‘A very useful tool for a not-very-experienced reviewer. Thank you’ . to ‘the resources/references are fantastic. the idea is fantastic and I will persevere, but the form is initially daunting’ . Many said ‘Thank you’ and ‘Congratulations’.