Missing data are common, challenging the validity of trial results.1 However, it is unclear how to characterize the extent of missing data. The CONSORT statement2 specifies reporting number lost to follow-up but does not define it operationally. The US Food and Drug Administration (FDA) recently published a review3 providing the follow-up completeness by a specific methodology for major oral antithrombotic trials. In this report, we compare the FDA follow-up rates with the published rates. We also analyze drug discontinuation rates as a possible contributory cause of incomplete follow-up and compare them with the outcomes because excessive incomplete follow-up may cause the end point rate difference, rather than representing true drug effect.
Marciniak TA, Cherepanov V, Golukhova E, Kim MH, Serebruany V. Drug Discontinuation and Follow-up Rates in Oral Antithrombotic Trials. JAMA Intern Med. 2016;176(2):257-259. doi:10.1001/jamainternmed.2015.6769