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Table 2 Exclusion rates by trial characteristics

From: Exclusion rates in randomized controlled trials of treatments for physical conditions: a systematic review

Variable (number of trials)

Unadjusted coefficient (95% CI)a

P value

Adjusted coefficient (95% CI)a

P value

Condition

 HIV infection (n = 32)

Reference

 

Reference

 

 Cancer (n = 24)

15.6 (5.0 to 26.2)

< 0.001

20.4 (8.8 to 32.0)

< 0.001

 Cardiovascular (n = 81)

31.8 (23.8 to 39.7)

0.003

34.0 (24.0 to 44.0)

< 0.001

 Respiratory (n = 78)

36.6 (27.8 to 45.3)

< 0.001

43.1 (31.9 to 54.2)

< 0.001

 Rheumatoid arthritis (n = 51)

44.6 (36.9 to 52.2)

< 0.001

43.9 (33.4 to 54.4)

< 0.001

 Diabetes (n = 16)

42.4 (28.2 to 56.7)

< 0.001

46.8 (31.1 to 62.6)

< 0.001

 Other conditions (n = 23)

19.5 (9.2 to 29.8)

< 0.001

25.0 (12.2 to 37.8)

< 0.001

Trial funding sourceb

 Public (n = 75)

Reference

 

Reference

 

 Industry (n = 203)

15.7 (9.6 to 21.7)

< 0.001

−4.7 (−11.0 to 1.6)

0.1

Comparison clinical population setting

 Primary care (n = 198)

Reference

 

Reference

 

 Specialist care (n = 107)

−6.2 (−11.7 to −0.6)

0.03

−3.0 (−9.0 to 3.0)

0.3

Year of trial publication

 1994–1999 (n = 81)

Reference

 

Reference

 

 2000–2003 (n = 78)

−4.0 (−11.4 to 3.3)

0.28

−4.7 (−10.8 to 1.4)

0.1

 2004–2011 (n = 75)

− 1.1 (−8.6 to 6.3)

0.76

− 6.2 (−13.1 to 0.7)

0.08

 2012–2018 (n = 71)

−0.3 (−7.4 to 7.9)

0.95

−6.5 (−13.8 to 0.7)

0.08

Risk of bias

 Low (n = 126)

Reference

 

Reference

 

 High/Unclear (n = 179)

17.2 (12.2 to 22.2)

< 0.001

9.2 (3.5 to 14.8)

0.002

  1. Abbreviations: CI confidence interval, HIV human immunodeficiency virus
  2. a The coefficients are interpreted as the percentage point difference in exclusion in each category compared with the reference
  3. b Twenty-seven trials did not report funding source