The STRATOS (STRengthening Analytical Thinking for Observational Studies) initiative has been set up to develop accessible and accurate guidance in the design and analysis of observational studies.
The STRATOS website (http://www.stratos-initiative.org/) has been launched recently. The website provides more details about the group and its plans.
Sauerbrei W., Abrahamowicz M., Altman D. G., Cessie S., Carpenter J., on behalf of the STRATOS initiative (2014), STRengthening Analytical Thinking for Observational Studies: the STRATOS initiative, Statist. Med., doi: 10.1002/sim.6265