Table 4 Percent (%) missing responsesa, by data element and trial start year
From: Update on the clinical trial landscape: analysis of ClinicalTrials.gov registration data, 2000–2020
Year | Facilities (%) | Randomized (%) | Masked (%) | Tx groups (%) | Primary purpose (%) | Intervention model (%) | Eligibility: sex (%) |
|---|---|---|---|---|---|---|---|
2000 | 17.4 | 21.5 | 22.5 | 55.6 | 2.6 | 25.8 | 0.5 |
2001 | 16.6 | 13.6 | 14.3 | 51.0 | 3.0 | 18.5 | 0.6 |
2002 | 17.0 | 7.7 | 6.7 | 49.0 | 5.8 | 10.0 | 0.2 |
2003 | 14.4 | 4.9 | 3.6 | 44.0 | 5.0 | 6.7 | 0.2 |
2004 | 14.0 | 4.0 | 3.4 | 42.8 | 5.0 | 5.3 | 0.2 |
2005 | 11.4 | 2.7 | 2.0 | 36.8 | 5.2 | 3.2 | 0.1 |
2006 | 9.3 | 1.7 | 1.7 | 27.0 | 4.0 | 2.2 | 0.1 |
2007 | 8.6 | 1.4 | 1.5 | 13.6 | 3.7 | 1.6 | 0.1 |
2008 | 8.3 | 1.2 | 1.0 | 5.8 | 4.3 | 1.2 | 0.1 |
2009 | 7.8 | 0.8 | 0.5 | 4.7 | 4.5 | 0.9 | 0.1 |
2010 | 7.3 | 0.6 | 0.4 | 3.3 | 4.4 | 0.6 | 0.1 |
2011 | 7.2 | 0.7 | 0.4 | 2.6 | 4.9 | 0.4 | 0.1 |
2012 | 7.9 | 0.5 | 0.4 | 1.3 | 4.2 | 0.4 | 0.1 |
2013 | 8.5 | 0.5 | 0.3 | 0.5 | 3.7 | 0.3 | 0.1 |
2014 | 10.8 | 0.3 | 0.3 | 0.4 | 3.5 | 0.3 | 0.1 |
2015 | 13.5 | 0.3 | 0.3 | 0.3 | 2.4 | 0.2 | 0.1 |
2016 | 14.9 | 0.3 | 0.4 | 0.3 | 1.1 | 0.2 | 0.1 |
2017 | 5.4 | 0.3 | 0.0 | 0.5 | 0.1 | 0.0 | 0.0 |
2018 | 4.9 | 0.3 | 0.0 | 0.5 | 0.0 | 0.0 | 0.1 |
2019 | 6.3 | 0.3 | 0.0 | 0.5 | 0.0 | 0.0 | 0.0 |
2020 | 7.6 | 0.1 | 0.0 | 0.6 | 0.0 | 0.0 | 0.0 |