Media type: E-Article Title: Impact of Length or Relevance of Questionnaires on Attrition in Online Trials: Randomized Controlled Trial Contributor: McCambridge, Jim; Kalaitzaki, Eleftheria; White, Ian R; Khadjesari, Zarnie; Murray, Elizabeth; Linke, Stuart; Thompson, Simon G; Godfrey, Christine; Wallace, Paul imprint: JMIR Publications Inc., 2011 Published in: Journal of Medical Internet Research Language: English DOI: 10.2196/jmir.1733 ISSN: 1438-8871 Keywords: Health Informatics Origination: Footnote: Access State: Open Access