Searching trials registers requires us to be flexible and adapt our approaches.
Go to the AustralianNew Zealand Clinical Trials Registry and explore how you would best search this resource.
Try to identify what is the default operator when two terms are used in the search
How can you do a phrase search?
Can you nest search terms using parentheses?
Can you use truncation?
Can you search in individual fields?
Can you save searches?
Can you export tagged output that could be loaded into bibliographic software such as EndNote?
Go to the UK trial register Be Part of Research
Try to identify what is the default operator when two terms are used in the search
How can you do a phrase search?
Can you nest search terms using parentheses?
Can you use truncation?
Can you search in individual fields?
Can you save searches?
Can you export tagged output that could be loaded into bibliographic software such as EndNote?
Go to the Pfizer Clinical Study Report Synopses website
Search for Lyrica - how many results do you find?
What types of documents does it provide?
Compare the information in documents to consider whether each document has unique value.
This exercise is designed to give you some hands-on experience of searching ClinicalTrials.gov and the WHO Portal (ICTRP).
Here are some example Ovid MEDLINE searches.
Consider which concepts you will use to search for trials within ClinicalTrials.gov, ICTRP and the Cochrane Library
Test out the search terms that you might use in each resource
Search 1: Pregabalin for chronic nerve pain associated with lower back problems or back pain
1 Pregabalin/
2 (pregabalin or lyrica).ti,ab.
3 1 or 2
4 Neuralgia/
5 (neuralgia or nerve pain$ or neuropathic pain$).ti,ab.
6 4 or 5
7 back pain/ or low back pain/
8 (back pain$ or back problem$).ti,ab.
9 7 or 8
10 3 and 6 and 9
Search 2: Physiotherapy for lymphoedema in breast cancer
1 Physical Therapy Modalities/
2 Massage/
3 (physical therap$ or physiotherap$ or massag$).ti,ab.
4 1 or 2 or 3
5 Lymphedema/
6 (lymphedem$ or lymphoedem$ or lymphatic edema$).ti,ab.
7 5 or 6
8 Breast Neoplasms/
9 (breast cancer$ or breast carcinoma$ or breast neoplas$).ti,ab.
10 8 or 9
11 4 and 7 and 10
Search 3: Pirfenidone for the treatment of idiopathic pulmonary fibrosis
1 Idiopathic Pulmonary Fibrosis/
2 Idiopathic Interstitial Pneumonias/
3 Lung Diseases, Interstitial/
4 (idiopathic pulmonary adj (fibros$ or pneumon$)).ti,ab.
5 ipf.ti,ab.
6 (idiopathic lung adj (fibros$ or pneumon$)).ti,ab.
7 (idiopathic interstitial adj (fibros$ or pneumon$)).ti,ab.
8 idiopathic fibros$.ti,ab.
9 fibrosing alveolit$.ti,ab.
10 interstitial lung disease$.ti,ab.
11 ((chronic or usual or fibrosing) adj interstitial pneumon$).ti,ab.
12 UIP.ti,ab.
13 ((interstitial fibros$ or alveolar fibros$) adj5 (lung or lungs or pulmonary)).ti,ab.
14 (diffuse adj5 (lung or lungs or pulmonary) adj5 fibros$).ti,ab.
15 ((parenchymal or fibrotic or restrictive) adj lung disease$).ti,ab.
16 or/1-15
17 pirfenidone.ti,ab.
18 (esbriet or pirespa or pirfenex or amr69 or deskar).ti,ab
19 17 or 18
20 16 and 19
Updated 5 April 2023
Alqaidoom Z, Nguyen P-Y, Awadh M, Page MJ. Impact of searching clinical trials registers in systematic reviews of pharmaceutical and non-pharmaceutical interventions: Reanalysis of meta-analyses. Research Synthesis Methods 2022. DOI: 10.1002/jrsm.1583
Altman, Douglas G.; Furberg, Curt D.; Grimshaw, Jeremy M.; Shanahan, Daniel R. (2014): Linked publications from a single trial: a thread of evidence. Trials 15, p. 369. DOI: 10.1186/1745-6215-15-369.
Banno, M.; Tsujimoto, Y.; Kataoka, Y. (2019): Studies registered in non-ClinicalTrials.gov accounted for an increasing proportion of protocol registrations in medical research. J Clin Epidemiol 116, pp. 106–113. DOI: 10.1016/j.jclinepi.2019.09.005.
Banno, Masahiro; Tsujimoto, Yasushi; Kataoka, Yuki (2020): Using the Cochrane Central Register of Controlled Trials to identify clinical trial registration is insufficient: a cross-sectional study. BMC Medical Research Methodology 20 (1), pp. 1–7.
Bashir, Rabia; Bourgeois, Florence T.; Dunn, Adam G. (2017): A systematic review of the processes used to link clinical trial registrations to their published results. Syst. Rev. 6 (1), p. 123. DOI: 10.1186/s13643-017-0518-3.
Berber, S.; Tan-Koay, A. G.; Opiyo, N.; Dwan, K.; Glanville, J. M.; Lasserson, T. J.; Willson, M. L. (2019): A cross-sectional audit showed that most Cochrane intervention reviews searched trial registers. J Clin Epidemiol 113, pp. 86–91. DOI: 10.1016/j.jclinepi.2019.05.020.
Bernard, R.; Weissgerber, T. L.; Bobrov, E.; Winham, S. J.; Dirnagl, U.; Riedel, N. (2020): fiddle: a tool to combat publication bias by getting research out of the file drawer and into the scientific community. Clin Sci (Lond) 134 (20), pp. 2729–2739. DOI: 10.1042/CS20201125.
Bero L, Lawrence R, Leslie L, Chiu K, McDonald S, Page MJ et al. Cross-sectional study of preprints and final journal publications from COVID-19 studies: discrepancies in results reporting and spin in interpretation. BMJ Open 2021; 11(7):e051821.
Beyer, Fiona; Wright, Kath (2011): Comprehensive searching for systematic reviews: a comparison of database performance. Cochrane Colloquium Madrid. Cochrane Collaboration, 2011.
Bhaumik, Soumyadeep; Biswas, Tamoghna (2013): Editorial policies of MEDLINE indexed Indian journals on clinical trial registration. Indian Pediatrics 50 (3), pp. 339–340.
Bidonde J, Meneses-Echavez JF, Busch AJ, Boden C. An algorithm provided as initial guidance for reporting registry records and published protocols in systematic reviews. J Clin Epidemiol 2020; 128:130–9.
Biocic, M.; Fidahic, M.; Cikes, K.; Puljak, L. (2019): Comparison of information sources used in Cochrane and non-Cochrane systematic reviews: a case study in the field of anesthesiology and pain. Res Synth Methods 10 (4): 597–605. DOI: 10.1002/jrsm.1375.
Boutron, Isabelle; Chaimani, Anna; Meerpohl, J. J.; Hróbjartsson, Asbjørn; Devane, Declan; Rada, Gabriel et al. (2020): Interventions for preventing and treating COVID-19: protocol for a living mapping of research and a living systematic review. Zenodo. Available online at https://zenodo.org/record/3903347#.YAmBm-j7SUm.
Boutron, Isabelle; Dechartres, Agnes; Baron, Gabriel; Li, Jacques; Ravaud, Philippe (2016): Sharing of Data From Industry-Funded Registered Clinical Trials. JAMA 315 (24), pp. 2729–2730.
Chen KY, Borglund EM, Postema EC, Dunn AG, Bourgeois FT. Reporting of clinical trial safety results in ClinicalTrials.gov for FDA-approved drugs: A cross-sectional analysis. Clinical trials (London, England) 2022:17407745221093567.
Committee on Strategies for Responsible Sharing of Clinical Trial, Data; Board on Health Sciences, Policy; Institute of, Medicine (2015): Sharing Clinical Trial Data: Maximizing Benefits, Minimizing Risk. Washington (DC): National Academies Press (US).
Cooper, C., R. Court, E. Kotas, and U. Schauberger. A Technical Review of Three Clinical Trials Register Resources Indicates Where Improvements to the Search Interfaces Are Needed. Res Synth Methods (Feb 8 2021).
Cooper, C. M.; Gray, H.; Barcenas, L.; Torgerson, T.; Checketts, J. X.; Vassar, M. (2020) An Evaluation of Reporting Guidelines and Clinical Trial Registry Requirements Among Addiction Medicine Journals. J Am Osteopath Assoc 120 (12), pp. 823–830. DOI: 10.7556/jaoa.2020.148.
Da Costa, F. A.; Da Costa Miranda, A. (2020) Using cancer registries to supplement clinical trial data and inform regulatory decision. Pharmacoepidemiol Drug Saf 29 (10), pp. 1319–1321. DOI: 10.1002/pds.4931.
Dal-Ré R, Goldacre B, Mahillo-Fernández I, DeVito NJ. European non-commercial sponsors showed substantial variation in results reporting to the EU trial registry. J. Clin. Epidemiol. 2021; 142:161–70.
Davis, M. K.; Fine, N. M. (2020) An Urgent Need for Data to Drive Decision Making: Rationale for the Canadian Registry for Amyloidosis Research. Can J Cardiol 36 (3):447–449. DOI: 10.1016/j.cjca.2019.12.005.
Dillman, A.; Zoratti, M. J.; Park, J. J. H.; Hsu, G.; Dron, L.; Smith, G. et al. (2020) The Landscape of Emerging Randomized Clinical Trial Evidence for COVID-19 Disease Stages: A Systematic Review of Global Trial Registries. Infect Drug Resist 13:4577–4587. DOI: 10.2147/IDR.S288399.
Domingues, M. A. P.; Camacho, R.; Rodrigues, P. P. (2020) CMIID: A comprehensive medical information identifier for clinical search harmonization in Data Safe Havens. In J Biomed Inform, p. 103669. DOI: 10.1016/j.jbi.2020.103669.
Dunn, A. G.; Coiera, E.; Bourgeois, F. T. (2018): Unreported links between trial registrations and published articles were identified using document similarity measures in a cross-sectional analysis of ClinicalTrials.gov. Journal of Clinical Epidemiology 95:94–101. Available online at https://www.sciencedirect.com/science/article/pii/S0895435617305966?via%3Dihub https://www.jclinepi.com/article/S0895-4356(17)30596-6/fulltext.
Eleftheriadi I, Ioannou T, Katechi V, Seehra J, Pandis N. Not enough SPIRIT shown in the registration and reporting of orthodontic trial protocols. Eur J Orthod 2023; 45(1):29–37.
Fain, Kevin M.; Rajakannan, Thiyagu; Tse, Tony; Williams, Rebecca J; Zarin, Deborah A. Results Reporting for Trials With the Same Sponsor, Drug, and Condition in Clinicaltrials.gov and Peer-Reviewed Publications. JAMA Intern. Med. 2018. DOI: 10.1001/jamainternmed.2018.0263.
Fleminger, J.; Goldacre, B. (2018) Prevalence of clinical trial status discrepancies: A cross-sectional study of 10,492 trials registered on both ClinicalTrials.gov and the European Union Clinical Trials Register. PLoS ONE [Electronic Resource] 13 (3), e0193088.
Fuller, K.; Bowers, A.; Vassar, M. (2020) Clinical trial registry use in minimally invasive surgical oncology systematic reviews and meta-analyses. BMJ Evid Based Med 25 (2): 1–2. DOI: 10.1136/bmjebm-2019-111207.
Fuller, Kaleb; Arthur, Wade; Riddle, Jonathan; Vassar, Matt (2019) Use of Clinical Trial Registries in Otolaryngology Systematic Reviews. JAMA Otolaryngology Head & Neck Surgery 25 (6):25. DOI: 10.1001/jamaoto.2019.0521.
Funk K, Zayas-Cabán T, Beck J. Phase 1 of the NIH Preprint Pilot: Testing the viability of making preprints discoverable in PubMed Central and PubMed. bioRxiv 2022.
Glanville, Julie M.; Duffy, Steven; McCool, Rachael; Varley, Danielle (2014) Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches? J. Med. Libr. Assoc. 102 (3):177–183. DOI: 10.3163/1536-5050.102.3.007.
Goff, Z. D.; Eric Heidel, R.; Hauptman, P. J. (2020) Is ClinicalTrials.gov searchable for patients with heart failure? J Card Fail. DOI: 10.1016/j.cardfail.2020.09.470.
Goldacre, Ben; DeVito, Nicholas J.; Heneghan, Carl; Irving, Francis; Bacon, Seb; Fleminger, Jessica; Curtis, Helen (2018) Compliance with requirement to report results on the EU Clinical Trials Register: cohort study and web resource. BMJ 362, k3218. DOI: 10.1136/bmj.k3218.
Goldacre, Ben; Drysdale, Henry; Powell-Smith, Anna; Dale, Aaron; Milosevic, Ioan; Slade, Eirion et al. (2016) The COMPare Trials Project. Available online at www.COMPare-trials.org.
Goodwin, T. R.; Skinner, M. A.; Harabagiu, S. M. (2018) Automatically Linking Registered Clinical Trials to their Published Results with Deep Highway Networks. AMIA Summits on Translational Science Proceedings 2017:54–63.
Gresham, G.; Meinert, J. L.; Gresham, A. G.; Meinert, C. L. (2020) Assessment of Trends in the Design, Accrual, and Completion of Trials Registered in ClinicalTrials.gov by Sponsor Type, 2000-2019. JAMA Netw Open 3 (8):e2014682. DOI: 10.1001/jamanetworkopen.2020.14682.
Gresham G, Meinert JL, Gresham AG, Piantadosi S, Meinert CL. Update on the clinical trial landscape: analysis of ClinicalTrials.gov registration data, 2000-2020. Trials 2022; 23(1):858..
Gusenbauer M, Haddaway NR. Which academic search systems are suitable for systematic reviews or meta-analyses? Evaluating retrieval qualities of Google Scholar, PubMed, and 26 other resources. Res Synth Methods. 2020;11(2):181-217. doi:10.1002/jrsm.1378
Halfpenny, Nicholas James Anthony; Quigley, Joan Mary; Thompson, Juliette Catherine; Scott, David Alexander (2016) Value and usability of unpublished data sources for systematic reviews and network meta-analyses. Evid. Based. Med. 21 (6): 208–213. DOI: 10.1136/ebmed-2016-110494.
Hardt, J. L. S.; Metzendorf, M. I.; Meerpohl, J. J. (2013) Surgical trials and trial registers: A cross-sectional study of randomized controlled trials published in journals requiring trial registration in the author instructions. Trials 14 (1). DOI: 10.1186/1745-6215-14-407.
Hausner, E.: Comment on: "Identification of additional trials in prospective trial registers for Cochrane systematic reviews. PLoS One. 2012;7(8):e42812. DOI: 10.1371/journal.pone.0042812" to W. A. van Enst, Scholten, R. J. P. M. and L. Hooft.
Huh KY, Yu KS, Lim HS, Kim H. Trends of clinical trials from 2017 to 2019 in Korea: an integrated analysis based on the Ministry of Food and Drug Safety (MFDS) and the Clinical Research Information Service (CRIS) registries. Transl Clin Pharmacol 2021; 29(4):186–96.
Hunter KE, Webster AC, Page MJ, et al. Searching clinical trials registers: guide for systematic reviewers. BMJ. 2022;377:e068791.
Huser, Vojtech; Cimino, James J. (2013) Evaluating adherence to the International Committee of Medical Journal Editors' policy of mandatory, timely clinical trial registration. J. Am. Med. Inform. Assoc. 20 (e1): e169-74. DOI: 10.1136/amiajnl-2012-001501.
Isojarvi, J.; Wood, H.; Lefebvre, C.; Glanville, J. (2018) Challenges of identifying unpublished data from clinical trials: getting the best out of clinical trials registers and other novel sources. Res Synth Methods 7 (4): 7. DOI: 10.1002/jrsm.1294.
Jorgensen, L.; Gotzsche, P. C.; Jefferson, T. (2020) Benefits and harms of the human papillomavirus (HPV) vaccines: systematic review with meta-analyses of trial data from clinical study reports. Syst Rev 9 (1):43. DOI: 10.1186/s13643-019-0983-y.
Juneja, A.; Gupta, J.; Yadav, N.; Sharma, S.; Panchal, Y.; Adhikari, T.; Rao, M. V. V. (2019) An overview of primary registries of WHO's international clinical trial registry platform. Ayu 40 (3): 141–146. DOI: 10.4103/ayu.AYU_62_20.
Knelangen, Marco; Hausner, Elke; Metzendorf, Maria-Inti; Sturtz, Sibylle; Waffenschmidt, Siw (2017) Trial registry searches for RCTs of new drugs required registry-specific adaptation to achieve adequate sensitivity. J. Clin. Epidemiol. 94:69–75. DOI: 10.1016/j.jclinepi.2017.11.003.
Knottnerus, J. A.; Tugwell, P. (2020) Trials embedded in cohorts, registries, and health care databases are gaining ground. J Clin Epidemiol 120:A5-A6. DOI: 10.1016/j.jclinepi.2020.02.007.
Köhler, Michael; Haag, Susanne; Biester, Katharina; Brockhaus, Anne Catharina; McGauran, Natalie; Grouven, Ulrich et al. (2015) Information on new drugs at market entry: retrospective analysis of health technology assessment reports versus regulatory reports, journal publications, and registry reports. BMJ 350:h796. DOI: 10.1136/bmj.h796.
Kotoulas, A.; Lambrou, G.; Koutsouris, D. D. (2019) Design and virtual implementation of a biomedical registry framework for the enhancement of clinical trials: colorectal cancer example. BMJ Health Care Inform 26 (1): 1–10.
Kunath F, Grobe HR, Keck B, Rücker G, Wullich B, Antes G et al. Do urology journals enforce trial registration? A cross-sectional study of published trials. BMJ Open 2011; 1(2):e000430.
Lanera, Corrado; Minto, Clara; Sharma, Abhinav; Gregori, Dario; Berchialla, Paola; Baldi, Ileana (2018) Extending PubMed searches to ClinicalTrials.gov through a machine learning approach for systematic reviews. J. Clin. Epidemiol. 103:22–30. DOI: 10.1016/j.jclinepi.2018.06.015.
Langnickel L, Podorskaja D, Fluck J. Pre2Pub—Tracking the Path From Preprint to Journal Article: Algorithm Development and Validation. J Med Internet Res 2022;24(4):e34072 https://www.jmir.org/2022/4/e34072 2022; 24(4):e34072. Available from: URL: https://www.jmir.org/2022/4/e34072.
Langnickel L, Darms J, Heldt K, Ducks D, Fluck J. Continuous development of the semantic search engine preVIEW: from COVID-19 to long COVID. Database (Oxford) 2022; 2022.
Lensen, S.; Macnair, A.; Love, S. B.; Yorke-Edwards, V.; Noor, N. M.; Martyn, M. et al. (2020) Access to routinely collected health data for clinical trials - review of successful data requests to UK registries. Trials 21 (1):398. DOI: 10.1186/s13063-020-04329-8.
Li, Z. J.; Liu, M. L.; Wang, J. N.; Liang, F. R. (2012) [Method and current situations on acupuncture clinical trial registration in the world]. Chen Tzu Yen Chiu Acupuncture Research 37 (1):86.
Lindsley, K.; Fusco, N.; Teeuw, H.; Mooij, E.; Scholten, R.; Hooft, L. (2020) Poor compliance of clinical trial registration among trials included in systematic reviews: a cohort study. J Clin Epidemiol. DOI: 10.1016/j.jclinepi.2020.12.016.
Lotfi, S.; Janani, L.; Ghalichi, L.; Tanha, K.; Solaymani-Dodaran, M. (2020) Scientometric measures of prospectively registered clinical trials over time: A comparison of IRCT and ClinicalTrials.gov. Med J Islam Repub Iran 34:116. DOI: 10.34171/mjiri.34.116.
Magnani, C. J.; Steinberg, J. R.; Harmange, C. I.; Zhang, X.; Driscoll, C.; Bell, A. et al. (2020) Clinical Trial Outcomes in Urology: Assessing Early Discontinuation, Results Reporting, and Publication in ClinicalTrials.Gov Registrations 2007-2019. J Urol, 101097JU0000000000001432. DOI: 10.1097/JU.0000000000001432.
Maguire, B. J.; McLean, A. R. D.; Rashan, S.; Antonio, E. S.; Bagaria, J.; Bentounsi, Z. et al. (2020) Baseline results of a living systematic review for COVID-19 clinical trial registrations. Wellcome Open Res 5:116. DOI: 10.12688/wellcomeopenres.15933.1.
Marshall, Iain J.; Nye, Benjamin; Kuiper, Joël; Noel-Storr, Anna; Marshall, Rachel; Maclean, Rory et al. (2020) Trialstreamer: A living, automatically updated database of clinical trial reports. Journal of the American Medical Informatics Association. DOI: 10.1093/jamia/ocaa163.
Maulik, M.; Gupta, J.; Juneja, A.; Adhikari, T.; Sharma, S.; Panchal, Y. et al. (2020) Letter on: "An analysis of deficiencies in the data of interventional drug trials registered with Clinical Trials Registry - India". Trials 21 (1):38. DOI: 10.1186/s13063-019-4010-3.
Mayer, C. S.; Huser, V. (2020) Computerized monitoring of COVID-19 trials, studies and registries in ClinicalTrials.gov registry. Peer J 8:e10261. DOI: 10.7717/peerj.10261.
Mayer CS, Huser V. regCOVID: Tracking publications of registered COVID-19 studies. BMC Medical Research Methodology 2022; 22(1):221.
Mayo-Wilson, Evan; Doshi, Peter; Dickersin, Kay (2015) Are manufacturers sharing data as promised? BMJ 351:h4169. DOI: 10.1136/bmj.h4169.
Mayo-Wilson, Evan; Li, Tianjing; Fusco, Nicole; Bertizzolo, Lorenzo; Canner, Joseph K.; Cowley, Terrie et al. (2017) Cherry-picking by trialists and meta-analysts can drive conclusions about intervention efficacy. J. Clin. Epidemiol. 91:95–110. DOI: 10.1016/j.jclinepi.2017.07.014.
Miron, L.; Goncalves, R. S.; Musen, M. A. (2020) Obstacles to the reuse of study metadata in ClinicalTrials.gov. Sci Data 7 (1):443. DOI: 10.1038/s41597-020-00780-z.
Munch, T.; Dufka, F. L.; Greene, K.; Smith, S. M.; Dworkin, R,H; Rowbotham, M. C. (2014) RReACT goes global: perils and pitfalls of constructing a global open-access database of registered analgesic clinical trials and trial results. Pain 155 (7): 1313–1317.
National Institutes of Health, Department of Health; Human, Services (2016) Clinical Trials Registration and Results Information Submission. Final rule. Fed. Regist. 81 (183):64981–65157. Available online at https://www.ncbi.nlm.nih.gov/pubmed/27658315 https://www.gpo.gov/fdsys/pkg/FR-2016-09-21/pdf/2016-22129.pdf.
Nazari G, Diep D, MacDermid JC. The state of trial registrations in the field of Orthopaedics in years 2015-2020. A meta-epidemiological study. Osteoarthr Cartil Open 2021; 3(4):100215.
Nelson JT, Tse T, Puplampu-Dove Y, Golfinopoulos E, Zarin DA. Comparison of Availability of Trial Results in ClinicalTrials.gov and PubMed by Data Source and Funder Type. JAMA 2023.
Nguyen, V. T.; Riviere, P.; Ripoll, P.; Barnier, J.; Vuillemot, R.; Ferrand, G. et al. (2020):Research response to coronavirus disease 2019 needed better coordination and collaboration: a living mapping of registered trials. J Clin Epidemiol 130: 107–116. DOI: 10.1016/j.jclinepi.2020.10.010.
Nye BE, Nenkova A, Marshall IJ, Wallace BC. Trialstreamer: Mapping and Browsing Medical Evidence in Real-Time. Proc Conf 2020; 2020:63–9.
Paladin I, Pranić SM. Reporting of the safety from allergic rhinitis trials registered on ClinicalTrials.gov and in publications: An observational study. BMC Medical Research Methodology 2022; 22(1):262.
Pansieri, Claudia; Pandolfini, Chiara; Bonati, Maurizio (2017) Clinical trial registries: more international, converging efforts are needed. Trials 18 (1):86. DOI: 10.1186/s13063-017-1836-4.
Patel, S.; Patel, A.; Patel, M.; Shah, U.; Solanki, N. (2020) Review and Analysis of Massively Registered Clinical Trials of COVID-19 using the Text Mining Approach. Rev Recent Clin Trials. DOI: 10.2174/1574887115666201202110919.
Patel S, Sternberg, P., Kim SJ. Publishing of Results from Ophthalmology Trials Registered on ClinicalTrials.gov. Ophthalmol Retina 2020; 4(7):754–5.
Raciti, D.; Yook, K.; Harris, T. W.; Schedl, T.; Sternberg, P. W. (2018) Micropublication: incentivizing community curation and placing unpublished data into the public domain. Database: The Journal of Biological Databases and Curation 01:1.
Rao, M. V. V.; Maulik, M.; Juneja, A.; Adhikari, T.; Sharma, S.; Gupta, J. et al. (2020) Clinical Trials Registry - India: A decadal perspective. Indian J Pharmacol 52 (4):272–282. DOI: 10.4103/ijp.IJP_24_20.
Riemer M, Kranke P, Helf A, Mayer D, Popp M, Schlesinger T et al. Trial registration and selective outcome reporting in 585 clinical trials investigating drugs for prevention of postoperative nausea and vomiting. BMC Anesthesiol 2021; 21(1):249.
Ross, J. S.; Waldstreicher, J.; Bamford, S.; Berlin, J. A.; Childers, K.; Desai, N. R. et al. (2018) Overview and experience of the YODA Project with clinical trial data sharing after 5 years. Sci Data 5:180268. DOI: 10.1038/sdata.2018.268.
Rybinski, M.; Xu, J.; Karimi, S. (2020) Clinical trial search: Using biomedical language understanding models for re-ranking. J Biomed Inform 109:103530. DOI: 10.1016/j.jbi.2020.103530.
Sekula, P.; Pressler, J. B.; Sauerbrei, W.; Goebell, P. J.; Schmitz-Drager, B. J. (2016) Assessment of the extent of unpublished studies in prognostic factor research: a systematic review of p53 immunohistochemistry in bladder cancer as an example. BMJ Open 6 (8):e009972. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013379/pdf/bmjopen-2015-009972.pdf.
Shokraneh, F.; Adams, C. E. (2017): Study-based registers of randomized controlled trials: Starting a systematic review with data extraction or meta-analysis. Bioimpacts 7 (4):209–217. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5801532/pdf/bi-7-209.pdf.
Smalheiser, N. R.; Holt, A. W. New improved Aggregator: predicting which clinical trial articles derive from the same registered clinical trial. JAMIA Open 2020;3 (3):338–341. DOI: 10.1093/jamiaopen/ooaa042.
Smalheiser NR, Holt AW. A web-based tool for automatically linking clinical trials to their publications. Journal of the American Medical Informatics Association 2022; 29(5):822–30. doi: 10.1093/jamia/ocab290
Soley-Bori, M; Ashworth, M; Bisquera, A; Dodhia, H; Lynch, R; Wang, Y; Fox-Rushby, J. Impact of multimorbidity on healthcare costs and utilisation: a systematic review of the UK literature. British Journal of General Practice 2021;71 (702):e39-e46. DOI: 10.3399/bjgp20X713897.
Song, G.; Cheng, M. Q.; Wei, X. W. (2020) Analysis of the WHO ICTRP for novel coronavirus clinical trial registrations. Medicine (Baltimore) 99 (43):e22840. DOI: 10.1097/MD.0000000000022840.
Steele, L.; Livesey, A.; Hong, A.; Thomson, J.; Flohr, C. (2020) Comparison of registered and published outcomes in randomized trials in dermatology journals: a cross-sectional analysis. Br J Dermatol 183 (6):1134–1136. DOI: 10.1111/bjd.19397.
Stegeman, I.; Leeflang, M.; Hooft, L. (Eds.) (2014) Implementation of prospective trial registration in the field of otolarynchology. Evidence-Informed Publich Health: Opportunities and Challenges. Abstracts of the 22nd Cochrane Colloquium; 2014 21-26 Sep. Hyderabad, India: John Wiley & Sons.
Stergiopoulos, Stella; Getz, Kenneth A.; Blazynski, Christine (2019) Evaluating the Completeness of ClinicalTrials.gov. Ther Innov Regul Sci 53 (3):307–317. DOI: 10.1177/2168479018782885.
Sudlow, Rebecca; Branson, Janice; Friede, Tim; Morgan, David; Whately-Smith, Caroline (2016) EFSPI/PSI working group on data sharing: accessing and working with pharmaceutical clinical trial patient level datasets - a primer for academic researchers. BMC Medical Research Methodology 16 (Suppl 1):73.
Sun, L. W.; Lee, D. J.; Collins, J. A.; Carll, T. C.; Ramahi, K.; Sandy, S. J. et al. (2019) Assessment of consistency between peer-reviewed publications and clinical trial registries. JAMA Ophthalmol 137 (5):552–556. DOI: 10.1001/jamaophthalmol.2019.0312.
Tai, F. M.; Willson, M. L.; Ghersi, D. (2012) Implications of searching multiple trial registries: how should we search ClinicalTrials.gov and WHO ICTRP? In. 2012 Cochrane Colloquium. Auckland, New Zealand.
Tetteh, O.; Nuamah, P.; Keyes, A. (2020) Addressing the quality of submissions to ClinicalTrials.gov for registration and results posting: The use of a checklist. Clin Trials, 1740774520942746. DOI: 10.1177/1740774520942746.
Thorlund, K.; Dron, L.; Park, J.; Hsu, G.; Forrest, J. I.; Mills, E. J. (2020) A real-time dashboard of clinical trials for COVID-19. Lancet Digit Health 2 (6):e286-e287. DOI: 10.1016/S2589-7500(20)30086-8.
Toure, Ahmed; Ghione, Paola; Phillips, Samantha; Klute, Kelsey; Leonard, John P.; Martin, Peter (2020) Lymphoma Study Titles on ClinicalTrials.gov Lack Details Necessary for Study Identification. Clinical Lymphoma Myeloma and Leukemia 20 (2):e82-e86. DOI: 10.1016/j.clml.2019.11.011.
TranspariMED, Pharma-Kampagne B, Test A, Health Action, International. Clinical trial transparency at European universities: mapping unreported drug trials; 2019. Available from: URL: https://haiweb.org/publication/clinical-trials-results/.
Vazquez E, Gouraud H, Naudet F, Gross CP, Krumholz HM, Ross JS et al. Characteristics of available studies and dissemination of research using major clinical data sharing platforms. Clin Trials 2021; 18(6):657–66. dOI: 10.1177/17407745211038524
Wallentin, L.; Gale, C. P.; Maggioni, A.; Bardinet, I.; Casadei, B. (2019) EuroHeart: European Unified Registries On Heart Care Evaluation and Randomized Trials. Eur Heart J 40 (33):2745–2749. DOI: 10.1093/eurheartj/ehz599.
Wilson, Lisa M.; Sharma, Ritu; Dy, Sydney M.; Waldfogel, Julie M.; Robinson, Karen A. (2017):Searching ClinicalTrials.gov did not change the conclusions of a systematic review. J. Clin. Epidemiol. 90:127–135. DOI: 10.1016/j.jclinepi.2017.07.009.
Won, J.; Kim, S.; Bae, I.; Lee, H. (2019) Trial registration as a safeguard against outcome reporting bias and spin? A case study of randomized controlled trials of acupuncture. PLoS One 14 (10):e0223305. DOI: 10.1371/journal.pone.0223305.
Zarin, D. A.; Crown, W. H.; Bierer, B. E. (2020) Issues in the registration of database studies. J Clin Epidemiol 121:29–31. DOI: 10.1016/j.jclinepi.2020.01.007.
Zarin, D. A.; Fain, K. M.; Dobbins, H. D.; Tse, T.; Williams, R. J. (2019) 10-year update on study results submitted to ClinicalTrials.gov. N Engl J Med 381 (20):1966–1974. DOI: 10.1056/NEJMsr1907644.
Zarin, Deborah A.; Tse, Tony; Williams, Rebecca J.; Rajakannan, Thiyagu (2017) Update on Trial Registration 11 Years after the ICMJE Policy Was Established. N. Engl. J. Med. 376 (4):383–391. DOI: 10.1056/NEJMsr1601330.
Zou, C. X.; Becker, J. E.; Phillips, A. T.; Garritano, J. M.; Krumholz, H. M.; Miller, J. E.; Ross, J. S. (2018) Registration, results reporting, and publication bias of clinical trials supporting FDA approval of neuropsychiatric drugs before and after FDAAA: a retrospective cohort study. Trials 19 (1):581. DOI: 10.1186/s13063-018-2957-0.