Library Guides: Systematic review guide: Grey literature sources

Grey literature sources

Trial registers

Finding clinical trials, research registers and research results
Links to registers around the world and tells you how to search them.
ClinicalTrials.gov
A database of publicly and privately supported clinical studies of human participants conducted around the world. It is one of the registers that you are required to search if you are doing a Cochrane review.
WHO International Clinical Trials Registry Platform
Aims to facilitate the prospective registration of all clinical trials, and the public accessibility of that information. One of the registers that you’re required to search if you are doing a Cochrane review.
CENTRAL
Available through the Cochrane Library as a source of reports of randomised and quasi-randomised controlled trials. Most records are taken from bibliographic databases (mainly PubMed and Embase), but records are also derived from other published and unpublished sources, including CINAHL, ClinicalTrials.gov and the WHO's International Clinical Trials Registry Platform.
UK trials since brexit
Pre-Brexit trials will still be on the EU Register (link below) but they won’t be updated.
EU Clinical Trials Register
Contains information on interventional clinical trials on medicines conducted in the European Union (EU), or the European Economic Area (EEA) which started after 1 May 2004.
ISRCTN
Contains clinical trials from around the world, including from 1 January 2022, all CTIMPs (Clinical Trials of Investigational Medicinal Products) in the UK, that are submitted to the Health Research Authority (HRA) using the Integrated Research Applications System (IRAS) combined review service. ISRCTN accepts all studies involving human subjects or populations with outcome measures assessing effects on human health and well-being, including studies in healthcare, social care, education, workplace safety and economic development.
Wikipedia list of clinical trials
Listed by country.

Repositories

CORE
The world’s largest collection of open access research papers. CORE’s mission is to aggregate all open access research outputs from repositories and journals worldwide and make them available to the public.
OpenDOAR
OpenDOAR is the quality-assured, global Directory of Open Access Repositories. You can search and browse through thousands of registered repositories based on a range of features, such as location, software or type of material held.
OAIster
A union catalog of millions of records that represent open access resources. It includes more than 50 million records that represent digital resources from more than 2,000 contributors.
BASE
A search engine specifically for academic web resources. It provides more than 350 million documents from more than 11,000 content providers. You can access the full texts of about 60% of the indexed documents for free (Open Access).
African Digital Research Repositories
A list of known repositories within the African continent has been compiled by the International African Institute.

Health Information

NHS Digital
Uses information and technology to improve health and care. Click on the data tab to access statistical publications and the results of their 200 national data collections.
The King's Fund
Information and Knowledge Services provide a unique and free source of information on health and social care management and policy, systems, services and leadership. They do not cover clinical issues and treatments.
The Nuffield Trust
An independent health think tank. They aim to improve the quality of health care in the UK by providing evidence-based research and policy analysis.
Fingertips
Public Health data for the UK.
The Health Foundation
An independent charity committed to bringing about better health and health care for people in the UK. It publishes research and analyses aiming to improve health and care policy.
NIHR Evidence
From the UK's National Institute for Health and Care Research. They create plain English summaries of either their single research studies or several covering a particular theme.
The NHS Confederation
A membership body for organisations that commission and provide National Health Service services. They focus on improving population health, delivering high-quality care and reducing health inequalities. Click on the Topics tab to see the themes that they research or click on publications for their podcasts, reports, briefings and case studies.
Mednar
A U.S. medically focused deep web search engine that aims to retrieve relevant medical information as if you were going to each individual website yourself.
The World Health Organisation
Includes its publications as well as health data and statistics.
OECD Health Statistics
Offers the most comprehensive source of comparable statistics on health and health systems across OECD countries.
Demographic and Health Surveys
Data on population, health, HIV, and nutrition through more than 400 surveys in over 90 countries.

Thesis

ProQuest Dissertations and Theses
The world's most comprehensive collection of dissertations and theses from around the world, offering millions of works from thousands of universities. Each year hundreds of thousands of works are added. Full-text coverage spans from 1743 to the present, with citation coverage dating back to 1637. Paid for by Imperial College London so you will need to be logged in or using an Imperial computer.
Networked Digital Library of Theses and Dissertations
Search the 6,194,628 electronic theses and dissertations contained in the NDLTD archive.
Open Access Theses and Dissertations
OATD aims to be the best possible resource for finding open access graduate theses and dissertations published around the world. Metadata (information about the theses) comes from over 1100 colleges, universities, and research institutions. It currently indexes nearly 7 million theses and dissertations.

Grey literature websites

Overton
An Imperial resource and so you will need to be signed in to Library Search to access it from outside Imperial. It is the world’s largest searchable index of policy documents, guidelines, think tank publications and working papers. It looks for the names of any researchers on expert panels, who are quoted in policy documents and will also find the links between documents such as if the research was picked up by intermediaries.
Global South Resources Document
This document was created by the University of Leeds to list places to find research from the global south.
World Bank Open Data
Access to a comprehensive set of data about development in countries around the globe such as development indicators, health, nutrition and population statistics and gender and education statistics.
Nesta
An independent charity that works to increase the innovation capacity of the UK and regularly publishes research papers. It looks at citizen engagement in public services, digital arts and media, future thinking, government innovation, health and aging, impact investment, innovation policy, new models for inclusive economic growth and opportunities for young people.