Table 2

Reporting of DMCs, interim analyses, stopping rules and early stopping

Trial characteristicN totalN (%)
DMCs
 Reported30055 (18)
 Not reported245 (82)
DMC members*
 Physician559 (16)
 Statistician6 (11)
 Clinical trial methodologist1 (2)
 Clinical pharmacologist3 (5)
 Bioethicist1 (2)
 Other3 (5)
 Not specified44 (80)
DMC responsibilities†
 Adjustment to enrolment557 (13)
 Make recommendations regarding termination6 (11)
 Review or approve the protocol3 (6)
 Review or make recommendations about trial conduct6 (11)
 Release interim data1 (2)
 Review or approve manuscripts or reports2 (4)
 Review safety data26 (47)
 Other‡4 (7)
 Not reported22 (40)
Reported on interim analyses
 Yes5514 (25)
 No41 (75)
Reported on stopping rules
 Yes5512 (22)
 No43 (78)
Reported that the trial stopped early
 Yes30013 (4)
 For benefit2/13 (15)
 For harm0/13 (0)
 For futility5/13 (38)
 Due to funding limitation1/13 (8)
 Due to inadequate recruitment5/13 (38)
 No287 (96)
  • *Nine of the 11 trials (82%) that reported on membership in the DMCs reported more than one type of member.

  • †13 of the 33 trials (39%) that reported on the DMC’s responsibilities reported more than one responsibility.

  • ‡Included changes to the statistical analyses and maintaining the randomisation sequence.

  • DMCs, data monitoring committee.