Table 1 Characteristics of included articles by registration status (n = 137)
Characteristic | Prior registration N = 54 | No Prior Registration N = 83 |
|---|---|---|
Publication characteristics | Â | Â |
   Peer reviewed | 53 (98%) | 76 (92%) |
   Year of publication |  |  |
1996-2002 | 0 (0%) | 29 (35%) |
2003-2004 | 12 (22%) | 28 (34%) |
2005-2006 | 14 (26%) | 19 (23%) |
2007-2008 | 28 (52%) | 7 (8%) |
   Impact factor, median (interquartile range)* | 15.5 (10.9-34.8) | 5.8 (4.0-10.5) |
   First or main report | 45 (83%) | 70 (84%) |
Study design characteristics | Â | Â |
   Comparison group |  |  |
Placebo | 40 (74%) | 32 (39%) |
Active treatment only | 14 (26%) | 51 (62%) |
   Non-inferiority trial - Yes | 2 (4%) | 9 (11%) |
   Primary efficacy outcome = survival | 21 (39%) | 9 (11%) |
   Stringent blinding (2/3 points) | 16 (30%) | 20 (24%) |
   Sample size, median (interquartile range) | 696 (150-923) | 283 (99-565) |
Statistical significance of primary outcome | Â | Â |
   Favorable to test drug | 36 (67%) | 44 (53%) |
   Inconclusive | 18 (33%) | 37 (45%) |
   Unfavorable | 0 (%) | 2 (2%) |
Conclusion | Â | Â |
   Favorable to test drug | 43 (80%) | 55 (66%) |
   About equal | 10 (18%) | 22 (27%) |
   Unfavorable | 1 (2%) | 6 (7%) |
Sponsored by test drug maker | 47 (87%) | 62 (75%) |