Background
INPLASY® is an international platform for registration of systematic review and meta-analysis protocols launched in March 2020. INPLASY® provides an online database where the protocols are maintained as a permanent public record and can be accessed on the website (www.inplasy.com).
Methods
We described the database features and registered information of all records published since the launch of the registry up to March 31st, 2022. Additionally, the website statistics dataset was analysed to explore user experience and promote data transparency.
Results
A total of 3082 records were registered in INPLASY®, and more than 91% of the protocols were published within 24 hours. Most submissions were from China, followed by Portugal, Brazil, Taiwan, and Spain. INPLASY® website received a total of 240,855 page views from 37,647 visitors during the first two years. These accesses were from 139 countries worldwide. Most of the accesses were from China, followed by The United States, Brazil, and Germany. The review status ‘‘completed and published’’ was observed in 323 protocols, and these studies were published in 156 different scientific peer-reviewed journals. The INPLASY® features included: (i) INPLASY® identifier, a unique protocol number; (ii) DOI number, the URL of the protocol linked to a specific DOI; (iii) ORCID update, INPLASY® updates the authors' ORCID page including their protocol automatically; and (iv) search tools, the protocols are freely accessible on www.inplasy.com.
Conclusions
The INPLASY® has several practical and useful features that should be considered when planning the registration of a systematic review protocol. Furthermore, the sharp increase in the number of protocols registered in INPLASY® in the first two years and the database statistics demonstrate that INPLASY® has become an important source of systematic review protocols. Therefore, authors should access INPLASY® before planning a future review study, either to avoid unintended duplication of efforts, or to obtain registration in a timely manner.