PeerJ Author 170 Points Contributions by role Author 135 Preprint Author 35 Contributions by subject area Bioinformatics Clinical Trials Epidemiology Statistics Data Mining and Machine Learning Patrizia Vivona PeerJ Author Summary PeerJ Contributions Articles 1 Preprints 1 February 1, 2019 Time arrow in published clinical studies/trials indexed in MEDLINE: a systematic analysis of retrospective vs. prospective study design, from 1960 to 2017 Michele M. Ciulla, Patrizia Vivona https://doi.org/10.7717/peerj.6363 PubMed 30723632 November 27, 2018 - Version: 1 Time arrow in published clinical studies/trials indexed in MEDLINE: a systematic analysis of Retrospective vs Prospective study design, from 1960 to 2017. Michele M Ciulla, Patrizia Vivona https://doi.org/10.7287/peerj.preprints.27385v1