Table 1 Characteristics of the published and unpublished studies included in the analysis (n = 62)
Published | Unpublished | p(chi-square) | Total | ||||
|---|---|---|---|---|---|---|---|
N | % | N | % | N | % | ||
Studies funded and started | 39 | 62.9 | 23 | 37.1 | 62 | 100.0 | |
Clinical area | 0.604 | ||||||
Oncology/hematology | 11 | 28.2 | 8 | 34.8 | 19 | 30.6 | |
Congenital and genetic disorders | 13 | 33.3 | 4 | 17.4 | 17 | 27.4 | |
Immune system disorders | 4 | 10.3 | 3 | 13.0 | 7 | 11.3 | |
Other | 11 | 28.2 | 8 | 34.8 | 19 | 30.6 | |
Prevalence of rare disease | 0.381 | ||||||
> 1/10,000 | 14 | 35.9 | 7 | 30.4 | 21 | 33.9 | |
1–9/100,000 | 12 | 30.8 | 11 | 47.8 | 23 | 37.1 | |
1–9/1,000,000 | 13 | 33.3 | 5 | 21.8 | 18 | 29.0 | |
Study characteristics | |||||||
Design | 0.055 | ||||||
Randomized clinical trials (RCT) | 21 | 53.8 | 18 | 78.3 | 39 | 62.9 | |
Uncontrolled clinical trials (CT) | 18 | 46.2 | 5 | 21.7 | 23 | 37.1 | |
Type of control group (n = 39) | 21 | 100.0 | 18 | 100.0 | 0.584 | 39 | 100.0 |
Active control | 11 | 52.4 | 11 | 61.1 | 22 | 56.4 | |
Placebo control/no treatment | 10 | 47.6 | 7 | 38.9 | 17 | 43.6 | |
Planned sample size (tertiles) | 0.901 | ||||||
< =46 patients | 13 | 33.3 | 8 | 34.8 | 21 | 33.9 | |
47-100 patients | 14 | 35.9 | 7 | 30.4 | 21 | 33.9 | |
> 100 patients | 12 | 30.8 | 8 | 34.8 | 20 | 32.3 | |
Mean | 98 | 107 | 101 | ||||
Median | 60 | 80 | 60 | ||||
Q1-Q3 | 30–120 | 29–177 | 30–124 | ||||
Special populations | 0.307 | ||||||
Only pediatrics | 12 | 30.8 | 6 | 26.1 | 18 | 29.0 | |
Also pediatrics | 4 | 10.3 | 0 | 0.0 | 4 | 6.5 | |
Only adults | 15 | 38.5 | 9 | 39.1 | 24 | 38.7 | |
Adults and elderly | 8 | 20.5 | 8 | 34.8 | 16 | 25.8 | |