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, GB

2 MRC General Practice Research Framework, London, GB

3 MRC Biostatistics Unit, Institute of Public Health, Cambridge, GB

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

5 MRC Biostatistics Unit, Institute of Public Health, London, GB

6 Department of Health Sciences and HYMS, University of York, York, GB

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

Corresponding Author: