Registration of randomized clinical trials - a challenge

Are Reports of Randomized Controlled Trials Improving over Time? A Systematic Review of 284 Articles Published in High-Impact General and Specialized Medical Journals

(2014) Matthew J. To et al.   PLoS One

The Quality of Registration of Clinical Trials: Still a Problem

(2014) Roderik F. Viergever et al.   PLoS One

Infrequent and incomplete registration of test accuracy studies: analysis of recent study reports

(2014) Daniël A Korevaar et al.   BMJ Open

Observational Studies: Getting Clear about Transparency

(2014)   PLOS MEDICINE

SPIRIT 2013: new guidance for content of clinical trial protocols

(2013) An-Wen Chan et al.   LANCET

Non-publication of large randomized clinical trials: cross sectional analysis

(2013) C. W. Jones et al.   BMJ-British Medical Journal