Table 1 Characteristics of 43 analyses identifying published articles from cohorts of trial registry entries
Study | Registry entry cohort | Published articles found | Trial registries included | Study purpose | Study publication year | Application domain | Proportion of links by process |
|---|---|---|---|---|---|---|---|
Hartung [70] | 305 | 110 | ClinicalTrials.gov | To determine consistency between registered trials and their publication | 2014 | Phase III or IV trials | Automatic = 95 Inferred = 15 |
Ross [51] | 677 | 315 | ClinicalTrials.gov | To assess the publication of registered trials in ClinicalTrials.gov | 2009 | Completed trials of phase II or higher | Automatic = 96 Inferred = 215 Inquired = 4 (contact = 117, responded = 44, published = 4) |
Bourgeois [71] | 546 | 362 | ClinicalTrials.gov | To determine whether funding source of these trials is associated with favorable published outcomes | 2010 | Anticholesteremics, antidepressants, antipsychotics, proton-pump inhibitors, and vasodilators | Inferred = unknown Inquired = unknown |
Liu [72] | 443 | 156 | ANZCTR, ISRCTN, ChiCTR, IRCT, DRKS, NTR, JPRN, SLCTR, CTRI, PACTR, Clinicaltrials.gov. | Publication rate of Chinese Trials in WHO Registries | 2010 | Trials sponsored by China | Automatic = 103 Inferred = 40 Inquired = 13 (contact = 54, responded = all, published = 1) |
Prenner [73] | 64 | 35 | Clinicaltrials.gov | To evaluate the rate of publication of registered clinical trials concerning age-related macular degeneration | 2009 | Muscular degeneration | Automatic = 8 Inferred = 27 |
Wildt [74] | 105 | 66 | ClinicalTrials.gov | To evaluate the adequacy of reporting of protocols for on diseases of the digestive system | 2011 | Gastrointestinal diseases | Inferred = 66 |
Gandhi [75] | 37 | 20 | ClinicalTrials.gov | To compare the published orthopaedic trauma trials following registration in ClinicalTrials.gov | 2011 | Orthopaedic trauma | Automatic and Inferred = unknown |
Ross [53] | 635 | 432 | ClinicalTrials.gov | To review patterns of publication of clinical trials funded by NIH in peer reviewed biomedical journals | 2012 | NIH-funded trials in biomedical journals | Automatic and Inferred = unknown |
Shamliyan [76] | 758 | 212 | ClinicalTrials.gov | To examine registration, completeness and publication of children studies | 2012 | Children studies funded by NIH | Inferred = 212 |
Vawdrey [77] | 62 | 47 | ClinicalTrials.gov | To measure the rate of non-publication and assess possible publication bias in clinical trials of electronic health records | 2012 | Electronic health record registered in clinicaltrials.gov | Automatic, inferred, and inquired = unknown |
Chapman [55] | 314 | 208 | ClinicalTrials.gov | To determine the rate of early discontinuation and non-publication of RCTs | 2014 | Surgery | Inferred = 192 Inquired = 16 (contact = 101, responded = 25, published = 16) |
Liu [52] | 505 | 115 | All 14 registries in ICTRP and ClinicalTrials.gov | To estimate bias risk and outcome-reporting bias in RCTs of traditional Chinese medicine | 2013 | Traditional Chinese medicines | Unknown |
van de Wetering [26] | 599 | 312 | NTR | To evaluate the reporting of trial registration numbers in biomedical publications | 2012 | Biomedical publications | Automatic and inferred = unknown Inquired = 0 (contact = 42, responded = 9, published = 0) |
Huser [15] | 8907 | 885 | ClinicalTrials.gov | Linking ClinicalTrials.gov with PubMed | 2013 | Interventional phase II or higher clinical trials | Automatic = 885 |
Stockmann [78] | 108 | 65 | ClinicalTrials.gov | To evaluate the publication patterns of obstetric studies registered in ClinicalTrials.gov | 2014 | Obstetric studies | Automatic = 45 Inferred = 20 |
Jones [79] | 585 | 414 | ClinicalTrials.gov | To estimate the frequency with which results of large randomized clinical trials registered with ClinicalTrials.gov are not available to the public | 2013 | Interventional RCTs with more than one arm | Automatic and inferred = unknown Inquired = 4 |
Riveros [80] | 594 | 297 | ClinicalTrials.gov | To assess timing and completeness of trial results posted at ClinicalTrials.gov and published in journals | 2013 | Interventional studies of phase III and IV | Unknown |
Korevaar [81] | 418 | 224 | ClinicalTrials.gov | To assess publication and reporting of test accuracy studies registered in ClinicalTrials.gov | 2014 | Test accuracy studies | Automatic = 154 Inferred = 64 Inquired = 6 (contact = 175, responded = 119, published = 6) |
Munch [82] | 391 | 118 | ICTRP, ClinicalTrials.gov | To analyse the perils and pitfalls of constructing a global open-access database of registered analgesic clinical trials | 2014 | Analgesic clinical trials | Inferred = 118 |
Hill [54] | 90 | 66 | ClinicalTrials.gov | To assess the characteristics of paediatric cardiovascular clinical trials registered on ClinicalTrials.gov | 2014 | Pediatric cardiovascular clinical trials | Unknown |
Khan [83] | 143 | 95 | ClinicalTrials.gov | To examine characteristics associated with the publication and timeliness of publication of RCTs of treatment of rheumatoid arthritis | 2014 | Rheumatoid Arthritis | Automatic and inferred = unknown Inquired = 1 (contact = 58, responded = 28, published = 1) |
Su [84] | 239 | 88 | All 14 registries in ICTRP and ClinicalTrials.gov | Outcome reporting bias | 2015 | Acupuncture | Automatic and inferred = unknown |
Hakala [85] | 177 | 102 | ClinicalTrials.gov | To quantify the proportion of trials for unsuccessfully licensed drugs that are not published | 2015 | Stalled drugs | Automatic = unknown Inferred = unknown Inquired = 0 (emails or calls = 42, responded = 9, published = 0) |
Pranic [50] | 81 | 21 | ClinicalTrials.gov | Outcome reporting bias | 2016 | Completed RCTs | Inferred = 21 |
Tang [86] | 300 | 222 | ClinicalTrials.gov | Outcome reporting bias | 2015 | Random sample of phase II or IV trials | Automatic and inferred = unknown |
Boccia [87] | 1109 | 120 | ClinicalTrials.gov | To assess the status of registration of observational studies | 2015 | Cancer | Inferred = 120 |
Saito [88] | 400 | 229 | ClinicalTrials.gov | To determine publication rates of completed US trials | 2014 | Interventional studies | Automatic = 126 Inferred = 103 |
Son [89] | 161 | 62 | ClinicalTrials.gov | To assess whether there is publication bias in industry funded clinical trials of degenerative diseases of the spine | 2015 | Diseases of the spine | Inferred = 62 |
Baudart [90] | 489 | 189 | ClinicalTrials.gov | To evaluate the publication rate of observational studies for intervention | 2016 | Observational studies with safety outcomes | Automatic = 75 Inferred = 99 Inquired = 15 (contact = 241, responded = 52, published = 15) |
Chahal [91] | 34 | 20 | ClinicalTrials.gov | To determine publication rates of RCTs in sports medicine | 2012 | Sports medicine | Automatic and Inferred = unknown |
Manzoli [92] | 355 | 176 | ClinicalTrials.gov, ICTRP, ANZCTR, ChiCTR, Current Control Trails, Clinical Study Register or Indian | To evaluate the extent of non-publication or delayed publication of registered RCTs on vaccines | 2014 | Vaccines | Automatic = 132 Inferred = 44 Inquired = 0, (contact = 24, responded = 0, published = unknown) |
Lebensburger [93] | 147 | 52 | ClinicalTrials.gov | To analyse ClinicalTrials.gov for registered sickle cell trials | 2015 | Sickle cells | Automatic = 28 Inferred = 24 |
Smith [94] | 101 | 25 | ClinicalTrials.gov | Outcome reporting bias | 2012 | Arthroplasty | Automatic = 10 Inferred = 15 |
Guo [95] | 35 | 11 | ClinicalTrials.gov | To estimate patterns of publication of clinical trials of endometriosis registered in ClinicalTrials.gov | 2013 | Endometriosis | Inquired = 8 Inferred = 3 |
Tsikkinis [96] | 333 | 141 | ClinicalTrials.gov | To identify all phase III prostate cancer trials in ClinicalTrials.gov with pending results | 2015 | Prostate cancer | Inferred = 141 |
Chen [97] | 4347 | 2458 | ClinicalTrials.gov | To assess publication rate and reporting of results for completed trials | 2016 | Interventional clinical trials | Automatic and inferred = unknown |
Ramsey [98] | 2028 | 357 | ClinicalTrials.gov | To assess the proportion of registered trials that are published | 2008 | Oncology | Automatic = 357 |
Hurley [99] | 142 | 62 | ClinicalTrials.gov | To assess the delayed publication of clinical trials | 2012 | Cystic fibrosis | Inferred = 59 Inquired = 3 (contact = 83, responded = 29, published = 3) |
Ioannidis [100] | 73 | 21 | Cochrane Controlled Clinical Trial Register, ISRCTN, ClinicalTrials.gov, ICTRP, GSK Clinical Study Register, and Indian, ANZCTR, and Chinese Clinical Trial Registries) | To assess publication delay | 2011 | Influenza A (H1N1) vaccination | Unknown |
Ohnmeiss [101] | 72 | 28 | ClinicalTrials.gov | To assess the publication of the studies registered on ClinicalTrials.gov. | 2015 | Spine studies | Automatic and inferred = unknown |
Gopal [102] | 6251 | 818 | ClinicalTrials.gov | To evaluated the rate of compliance with the FDA mandatory results reporting in clinicaltrials.gov | 2012 | Interventional studies | Automatic = 818 |
Lampert [103] | 76 | 40 | ClinicalTrials.gov | To determine selective outcome reporting and delay of publication | 2015 | Epilepsy | Automatic = 32 Inferred = 7 Inquired = 1 |
Gandhi [104] | 46 | 2 | ISRCTN, ClinicalTrials.gov, ANZCTR | To determine the extent to which ongoing and future RCTs in diabetes will ascertain patient-important outcomes | 2008 | Diabetes | Unknown |