Register of trials

Our register has been developed since 1994, and the Information Specialist maintains it periodically through:

  • Systematic searches of major databases,
  • Email alerts for update searches,
  • Searching for grey literature,
  • Hand-searching of journals and conference proceedings,
  • Checking references of relevant papers and their citations, and
  • Contacting the researchers, organisations and companies.

This register contains 25,328 reports for 18,079 coded studies (May 29, 2018).

All reports of controlled trials relevant to the scope of this group (whether randomisation is described or implied) are acquired, coded and included in our Study-Based Register. This register, therefore, contains some quasi-random studies and trials that do not make the allocation procedure explicit. Currently, it also contains non-clinical studies where physiological outcomes are recorded in preference to clinical measures. It does not contain studies where before and after or single-group design has been used.

The register is maintained using MeerKat 1.6, which stores references as studies, and it gets updated daily. The group also uses the Cochrane Register of Studies (CRS) to deliver some records to the Cochrane Central Register of Controlled Trials (CENTRAL). Because of copyrighted materials and lack of technological support in CRS for some languages such as the Chinese language, CENTRAL covers only about 20% of our register's references.

Access to the register by reviewers:

Our register can only be searched by the Information Specialist on behalf of Cochrane Schizophrenia Group authors.

Our list of search strategies is available to download.

Publications relevant to this register:

  • Shokraneh F, CE Adams. Study-Based Registers of Randomized Controlled Trials: Starting a Systematic Review with Data Extraction or Meta-Analysis. BioImpacts 2017; 7(4): 209–217. DOI:
  • Shokraneh F, CE Adams. Study-Based Registers Reduce Waste in Systematic Reviewing: Discussion and Case Report. Systematic Reviews 2019; 8: 129. DOI:
  • Shokraneh F, CE Adams. Cochrane Schizophrenia Group’s Study-Based Register of Randomized Controlled Trials: Development and Content Analysis. Schizophrenia Bulletin Open 2020. InPress. DOI:
  • Shokraneh F, CE Adams. Classification of All Pharmacological Interventions Tested in Trials Relevant to People with Schizophrenia: A Study‐Based Analysis. Health Information and Libraries Journal 2021; InPress. DOI:
  • Roberts MT, Shokraneh F, Sun Y, Groom M, Adams CE. Classification of Psychotherapy Interventions for People with Schizophrenia: Development of the Nottingham Classification of Psychotherapies. Evidence-Based Mental Health 2020; InPress. DOI:

If you have any queries about accessing the register, please contact our Information Specialist (to be confirmed)