title: Electronic reminders did not improve postal questionnaire response rates or response times: a randomized controlled trial.
abstract: OBJECTIVE
  We aim to evaluate the effectiveness of electronic reminders (ERs) to improve the response rates and time to response of postal questionnaires in a health research setting.
  
  
  METHODS
  This pragmatic randomized controlled trial (RCT) was nested within a multicenter RCT of yoga for lower back pain. Participants who provided an electronic mail address and/or mobile phone number were randomized to receive an ER or no reminder (controls) on the day they were due to receive a follow-up questionnaire.
  
  
  RESULTS
  One hundred twenty-five participants (32 males and 93 females) mean age 46 (standard deviation: 11, range: 20-65) were randomized to ER (n=62) or controls (n=63). Overall 85.6% of participants returned postal questionnaires (87.1% ER group and 84.1% from controls). No significant differences were found between the two groups for response rate (difference between groups=3.0%, 95% confidence interval [CI]=-10, 16; P=0.64) or time to response after adjusting for age, gender, and treatment allocation (χ(2) ([3df])=7.10; P=0.07).
  
  
  CONCLUSIONS
  In the present RCT, we found little evidence for the effectiveness of ERs to increase response rates or time to respond for the return of questionnaires in this study population group.
authors.affiliation: Department of Health Sciences, York Trials Unit, The University of York, Heslington, York YO10 5DD, UK. mm714@york.ac.uk
authors.forename: Mei-See
authors.initials: MS
authors.lastname: Man
authors.forename: Helen E
authors.initials: HE
authors.lastname: Tilbrook
authors.forename: Shalmini
authors.initials: S
authors.lastname: Jayakody
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Hewitt
authors.forename: Helen
authors.initials: H
authors.lastname: Cox
authors.forename: Ben
authors.initials: B
authors.lastname: Cross
authors.forename: David J
authors.initials: DJ
authors.lastname: Torgerson
mesh_terms: D000328:Adult; D000368:Aged; D040421:Cell Phone; D034742:Electronic Mail; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D017116:Low Back Pain / Q000517:prevention & control / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009042:Motivation; D011177:Postal Service; D017010:Reminder Systems / Q000706:statistics & numerical data*; D035842:Research Subjects / Q000523:psychology; D011795:Surveys and Questionnaires; D006113:United Kingdom; D015013:Yoga; D055815:Young Adult