The websites below have important information on the proper standards for report and conducting Randomized Controlled Trials (The CONSORT statement), Diagnostic accuracy studies (The STARD Inititiative) and Diagnostic Predictive Models (TRIPOD)
here are the links to the respective websites:
CONSORT: http://www.consort-statement.org/
STARD Initiative: http://www.equator-network.org/reporting-guidelines/stard/
TRIPOD: https://www.tripod-statement.org/
Documents on study design, flow diagrams and standards for reporting are available from these websites and you can access the relevant free, open access papers as well