Woloshin S, Schwartz LM, Bagley PJ, Blunt HB, White B. Characteristics of interim publications of randomized clinical trials and comparison with final publications. JAMA. 2018;319(4). doi: 10.1001/jama.2017.20653.
Publication of interim results of randomized trials can be consequential, potentially undermining trial integrity by unblinding or encouraging dropouts and crossovers, introducing uncertainty because results based on fewer outcomes are less precise, or overstating true treatment effects as demonstrated primarily in trials terminated early but also in ongoing trials. Nevertheless, because interim results are new and often promising, they may generate substantial interest, which can be misleading if results change. We describe the characteristics of interim publications from ongoing randomized trials and compare their consistency and prominence with those of final publications.