Table 2 Distribution of 108 included articles by study characteristics (study design, continent of first author’s affiliation, and presence or absence of a declared financial competing interest) and registration status (prospective, retrospective and unregistered)
From: When are clinical trials registered? An analysis of prospective versus retrospective registration
Prospectively registered studies (n = 33) | Retrospectively registered studies (n = 72) | Unregistered studies (n = 3) | |
|---|---|---|---|
Study design | |||
- RCT | 26 | 56 | 1 |
- Pilot RCT | 4 | 7 | 1 |
- Interventional, non-randomised | 3 | 9 | 1 |
Continent of affiliation (first author) | |||
- Africa | 1 | 1 | 0 |
- Asia | 6 | 17 | 1 |
- Australia | 3 | 8 | 0 |
- Europe | 17 | 33 | 1 |
- North America | 5 | 8 | 1 |
- South America | 1 | 5 | 0 |
Financial competing interests (CI) of any authors | |||
- Financial CI declared | 8 | 8 | 0 |
- No financial CI declared | 25 | 64 | 3 |