Electronic Thesis and Dissertation Repository


Master of Science


Epidemiology and Biostatistics


Dr. Janet Martin


BACKGROUND: Evidence Reversal (ER) is the phenomenon whereby new and stronger evidence contradicts previously established evidence.

OBJECTIVES: To quantify evidence reversals and to determine characteristics associated with reversibility.

METHODS: Original articles from the New England Journal of Medicine (2000 to 2016) were screened for three inclusion criteria: tested a clinical practice; Randomized Controlled Trial design; and tested an established clinical practice. The proportion of RCTs that represented ER was determined. Association of trial characteristics with reversal was explored using logistic regression in order to inform a potential framework of reversibility.

RESULTS: In total, 611 RCTs met the inclusion criteria, of which 54% were evidence reversals. Based on variables associated with ER, a reversibility framework was proposed, comprised of eight trial characteristics.

CONCLUSION: More than 50% of RCTs published in the NEJM that test established practices are evidence reversals. The characteristics of RCTs that are associated with reversal will inform future research to further understand reversibility.

Available for download on Monday, September 10, 2018