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Table 1 Characteristics of completed phase 3 or 4 randomized clinical trials with results posted and a superiority hypothesis by whether a treatment effect estimate and/or p-value is reported at ClinicalTrials.gov

From: Reporting of statistically significant results at ClinicalTrials.gov for completed superiority randomized controlled trials

Characteristics

Categories

Trials with treatment effect estimate and/or p-value reported

(N = 1400)

Trials with no treatment effect estimate or p-value reported

(N = 1423)

Phase of the study

Phase 3

948 (68)

728 (51)

Phase 4

452 (32)

695 (49)

Intervention type

Drug

1088 (78)

1014 (71)

Mixed interventions

180 (13)

148 (10)

Biological

48 (3)

96 (7)

Device

40 (3)

97 (7)

Other

44 (3)

68 (5)

Control group

Placebo or no treatment

822 (59)

516 (36)

Active treatment

578 (41)

907 (64)

Sponsorship

Industry totally or partly

1162 (83)

1055 (74)

Academic only

238 (17)

368 (26)

Countries

Single country

646 (46)

982 (69)

Multiple countries

568 (41)

292 (21)

Not reported

186 (13)

149 (10)

Location

At least one site in the USA

846 (61)

822 (58)

No site in the USA

368 (26)

452 (32)

Not reported

186 (13)

149 (10)

Subject to the FDAAA

Yes

951 (68)

843 (59)

No

377 (27)

556 (39)

Not reported

72 (5)

24 (2)

Centers

Multicenter

929 (66)

696 (49)

Single center

285 (20)

578 (41)

Not reported

186 (13)

149 (10)

Sample size

Median (Q1-Q3)

270 (116–520)

156 (60–378)

Time to results first received at ClinicalTrials.gov (month)

Median (Q1-Q3)

13.5 (11.7–26.4)

17.1 (12.0–32.3)

  1. Data are presented as n (%) unless indicated. FDAAA US Food and Drug Administration Amendments Act, IQR Q1-Q3