Table 2 Trial characteristics, comparison between the two study periods and publication status.

Type

Interventional

297 (87 %)

158 (93 %)

139 (82 %)

.002

159 (54 %)

138 (47 %)

<.0001

Observational

43(13 %)

12 (7 %)

31 (18 %)

9 (21 %)

34 (79 %)

Phase

I

47 (14 %)

28 (21 %)

19 (17 %)

.917^b

21 (45 %)

26 (55 %)

.161^b

I/II or II

145 (43 %)

80 (59 %)

65 (60 %)

85 (59 %)

60 (41 %)

II/III or III

45 (13 %)

24 (18 %)

21 (19 %)

29 (64 %)

16 (36 %)

IV

8 (2 %)

4 (3 %)

4 (4 %)

6 (75 %)

2 (25 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

52 (15 %)

Randomization status

Randomized

107 (32 %)

60 (39 %)

47 (34 %)

.409

63 (59 %)

44 (41 %)

.229

Non-randomized

186 (55 %)

95 (61 %)

91 (66 %)

96 (52 %)

90 (48 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

4 (1 %)

Control status

Placebo only

29 (9 %)

16 (10 %)

13 (10 %)

.136^b

15 (52 %)

14 (48 %)

.519^b

Active-control only

74 (22 %)

34 (22 %)

40 (29 %)

41 (55 %)

33 (45 %)

Both placebo and active-control

17 (5 %)

13 (8 %)

4 (3 %)

12 (71 %)

5 (29 %)

No control

172 (51 %)

92 (59 %)

80 (58 %)

90 (52 %)

82 (48 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

5 (2 %)

Blinding

Open-label

255 (75 %)

128 (82 %)

127 (93 %)

.006^b

134 (53 %)

121 (48 %)

.286^b

Single-blind

9 (3 %)

5 (3 %)

4 (3 %)

4 (44 %)

5 (56 %)

Double (or Triple) blind

30 (9 %)

24 (15 %)

6 (4 %)

20 (67 %)

10 (33 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

3 (1 %)

Interventional model

Parallel

107 (32 %)

54 (35 %)

53 (39 %)

.432^b

60 (56 %)

47 (44 %)

.184^b

Crossover

9 (3 %)

7 (5 %)

2 (2 %)

4 (44 %)

5 (56 %)

Factorial

4 (1 %)

2 (1 %)

2 (2 %)

4 (100 %)

0 (0 %)

Single-group assignment

172 (51 %)

92 (59 %)

80 (58 %)

90 (52 %)

82 (48 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

5 (2 %)

Endpoint classification

Safety only

28 (8 %)

15 (10 %)

13 (10 %)

.336^b

12 (43 %)

16 (57 %)

.069^b

Efficacy only

103 (30 %)

49 (32 %)

54 (40 %)

49 (48 %)

54 (52 %)

Both Safety and Efficacy

160 (47 %)

91 (59 %)

69 (51 %)

96 (60 %)

64 (40 %)

Not applicable (observational studies)

43 (13 %)

Unknown (missing values)

6 (2 %)

Age

Included adults (≥18 years, >65 years)

51 (15 %)

28 (18 %)

23 (15 %)

.697^b

29 (57 %)

22 (43 %)

.716^b

Included adults and older adults (≥65 years)

237 (70 %)

121 (76 %)

116 (75 %)

117 (49 %)

120 (51 %)

Included adults and children (<18 years)

5 (2 %)

2 (1 %)

3 (2 %)

2 (40 %)

3 (60 %)

Included older adults (≥65 years) only

20 (6 %)

8 (5 %)

12 (8 %)

9 (45 %)

11 (55 %)

Included children (<18 years) only

0 (0 %)

0 (0 %)

0 (0 %)

0 (0 %)

0 (0 %)

Unknown (missing values)

27 (8 %)

Gender

Male only

1 (0 %)

0 (0 %)

1 (1 %)

.136^b

0 (0 %)

1 (100 %)

.132^b

Female only

225 (66 %)

106 (62 %)

119 (70 %)

105 (47 %)

120 (53 %)

Both male and female

114 (34 %)

64 (38 %)

50 (29 %)

63 (55 %)

51 (45 %)

Number of Centres

Single

50 (15 %)

18 (17 %)

32 (29 %)

.035

34 (68 %)

16 (32 %)

1.000

Multiple

164 (48 %)

87 (83 %)

77 (71 %)

112 (68 %)

52 (32 %)

Unknown (missing values)

126 (37 %)

Number of Countries

Single

301 (89 %)

148 (88 %)

153 (91 %)

.469

143 (48 %)

158 (53 %)

.013

Multiple

36 (11 %)

20 (12 %)

16 (10 %)

25 (69 %)

11 (31 %)

Unknown (missing values)

3 (1 %)

Country

US/Canada only

209 (62 %)

105 (63 %)

104 (62 %)

.855^b

100 (48 %)

109 (52 %)

.013^b

International (outside USA/Canada) only

102 (30 %)

49 (29 %)

53 (31 %)

48 (47 %)

54 (53 %)

USA/Canada and International

26 (8 %)

14 (8 %)

12 (7 %)

20 (77 %)

6 (23 %)

Unknown (missing values)

3 (1 %)

Primary sponsor

Industry

91 (27 %)

45 (27 %)

46 (27 %)

.609

45 (50 %)

46 (51 %)

.545^b

Government (US and non-US)

42 (12 %)

24 (14 %)

18 (11 %)

24 (57 %)

18 (43 %)

Non-industry/non-government

207 (61 %)

101 (59 %)

106 (62 %)

99 (48 %)

108 (52 %)

Registered before initiation

Yes

59 (17 %)

22 (14 %)

37 (27 %)

.005

35 (59 %)

24 (41 %)

.171

No

241 (71 %)

139 (86 %)

102 (73 %)

119 (49 %)

122 (51 %)

Unknown (missing dates)

40 (12 %)

Registered within 21 days of initiation

Yes

93 (27 %)

30 (19 %)

63 (30 %)

.000

47 (51 %)

46 (50 %)

.980

No

217 (64 %)

127 (81 %)

90 (59 %)

110 (51 %)

107 (49 %)

Unknown (missing dates)

30 (9 %)

Completed/terminated

Completed

288 (85 %)

148 (87 %)

140 (82 %)

.228

155 (54 %)

133 (46 %)

<.0001

Terminated

52 (15 %)

22 (13 %)

30 (18 %)

13 (25 %)

39 (75 %)

Registered before completion/termination?

Yes

283 (84 %)

131 (78 %)

152 (90 %)

.002

135 (48 %)

148 (52 %)

.155

No

55 (16 %)

38 (23 %)

17 (10 %)

32 (58 %)

23 (42 %)

Unknown (missing dates)

2 (1 %)

Results posted in ClinicalTrials.gov?

Yes

59 (17 %)

20 (12 %)

39 (23 %)

.007

31 (53 %)

28 (48 %)

.597

No

281 (83 %)

150 (88 %)

131 (77 %)

137 (49 %)

144 (51 %)

Publication link available

Yes

77 (23 %)

41 (24 %)

36 (21 %)

.517

77 (100 %)

0 (0 %)

<.0001

No

263 (77 %)

129 (76 %)

134 (79 %)

91 (35 %)

172 (51 %)