Code-break procedure

A code-break procedure is a set of rules which determine when planned unblinding should occur in a blinded experiment. FDA guidelines recommend that sponsors of blinded trials include a code-break procedure in their standard operating procedure. A code-break procedure should only allow a participant to be unblinded before the conclusion of a trial in the event of an emergency.^[1] Code-break usually refers to the unmasking of treatment allocation, but can refer to any form of unblinding.

Traditionally, each patient's treatment allocation data was stored in a sealed envelopes, which was to be opened to break code. However, this system is prone to abuse. Reports of researchers opening envelopes prematurely or holding the envelopes up to lights to determine their contents has led some researchers to say that the use of sealed envelopes is no longer acceptable.^[2]^[3] As of 2016^[update], sealed envelopes were still in use in some clinical trials.^[4] Modern clinical trials usually store this information in computer files.

References

^ "Guidance for Clinical Trial Sponsors" (PDF). www.webcitation.org. Archived from the original (PDF) on 22 April 2019. Retrieved 24 April 2019.
^ Furberg, CD; Soliman, EZ (February 2008). "Double-blindness protects scientific validity". Journal of Thrombosis and Haemostasis. 6 (2): 230–1. doi:10.1111/j.1538-7836.2008.02836.x. PMID 18021306.
^ Torgerson, DJ; Roberts, C (7 August 1999). "Understanding controlled trials. Randomisation methods: concealment". BMJ (Clinical Research Ed.). 319 (7206): 375–6. doi:10.1136/bmj.319.7206.375. ISSN 0959-8138. PMC 1126995. PMID 10435967.
^ Fava, M.; Johe, K.; Ereshefsky, L.; Gertsik, L. G.; English, B. A.; Bilello, J. A.; Thurmond, L. M.; Johnstone, J.; Dickerson, B. C.; Makris, N.; Hoeppner, B. B.; Flynn, M.; Mischoulon, D.; Kinrys, G.; Freeman, M. P. (2016). "A Phase 1B, randomized, double blind, placebo controlled, multiple-dose escalation study of NSI-189 phosphate, a neurogenic compound, in depressed patients". Molecular Psychiatry. 21 (10): 1372–1380. doi:10.1038/mp.2015.178. ISSN 1476-5578. PMC 5030464. PMID 26643541.

Clinical research and experimental design

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