Impact of Length or Relevance of Questionnaires on Attrition in Online Trials: Randomized Controlled Trial

Impact of Length or Relevance of Questionnaires on Attrition in Online Trials: Randomized Controlled Trial

Impact of Length or Relevance of Questionnaires on Attrition in Online Trials: Randomized Controlled Trial

Jim McCambridge   1 ;   Eleftheria Kalaitzaki   2 ;   Ian R. White   3 ;   Zarnie Khadjesari   4 ;   Elizabeth Murray   4 ;   Stuart Linke   4 ;   Simon G. Thompson   5 ;   Christine Godfrey   6 ;   Paul Wallace   7

1 Faculty of Public Health & Policy, London School of Hygiene & Tropical Medicine, London, United Kingdom

2 MRC General Practice Research Framework, London, United Kingdom

3 MRC Biostatistics Unit, Institute of Public Health, Cambridge, United Kingdom

4 E-health Unit, Research Department of Primary Care and Population Health, University College London, London, United Kingdom

5 MRC Biostatistics Unit, Institute of Public Health, London, United Kingdom

6 Department of Health Sciences and HYMS, University of York, York, United Kingdom

7 E-health Unit, Research Department of Primary Care & Population Health, University College London, London, United Kingdom

†deceased

Corresponding Author:

  • Jim McCambridge
  • Faculty of Public Health & Policy
  • London School of Hygiene & Tropical Medicine
  • 15 - 17 Tavistock Place
  • London, WC1H 9SH
  • United Kingdom
  • Phone: 44 (0)20 7927 2945
  • Fax: 44 (0)20 7927 7958
  • Email: Jim.McCambridge@lshtm.ac.uk