title: Towards socially inclusive research: an evaluation of telephone questionnaire administration in a multilingual population.
abstract: BACKGROUND
  Missing data may bias the results of clinical trials and other studies. This study describes the response rate, questionnaire responses and financial costs associated with offering participants from a multilingual population the option to complete questionnaires over the telephone.
  
  
  METHODS
  
  
  
  METHODS
  Before and after study of two methods of questionnaire completion.
  
  
  METHODS
  Seven hundred and sixty five pregnant women from 25 general practices in two UK inner city Primary Care Trusts (PCTs) taking part in a cluster randomised controlled trial of offering antenatal sickle cell and thalassaemia screening in primary care. Two hundred and four participants did not speak English. Sixty one women were offered postal questionnaire completion only and 714 women were offered a choice of telephone or postal questionnaire completion.
  
  
  METHODS
  (i) Proportion of completed questionnaires, (ii) attitude and knowledge responses obtained from a questionnaire assessing informed choice.
  
  
  RESULTS
  The response rate from women offered postal completion was 26% compared with 67% for women offered a choice of telephone or postal completion (41% difference 95% CI Diff 30 to 52). For non-English speakers offered a choice of completion methods the response rate was 56% compared with 71% for English speakers (95% CI Diff 7 to 23). No difference was found for knowledge by completion method, but telephone completion was associated with more positive attitude classifications than postal completion (87 vs 96%, 95% CI diff 0.006 to 15). Compared with postal administration the additional costs associated with telephone administration were pound3.90 per questionnaire for English speakers and pound71.60 per questionnaire for non English speakers.
  
  
  CONCLUSIONS
  Studies requiring data to be collected by questionnaire may obtain higher response rates from both English and non-English speakers when a choice of telephone or postal administration (and where necessary, an interpreter)is offered compared to offering postal administration only. This approach will, however, incur additional research costs and uncertainty remains about the equivalence of responses obtained from the two methods.
authors.affiliation: Department of Psychology (at Guy's), Health Psychology Section Institute of Psychiatry, King's College London, London, UK. elizabeth.dormandy@kcl.ac.uk
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dormandy
authors.forename: Katrina
authors.initials: K
authors.lastname: Brown
authors.forename: Erin P
authors.initials: EP
authors.lastname: Reid
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Marteau
mesh_terms: D002755:Choice Behavior; D003625:Data Collection / Q000379:methods*; D005260:Female; D005820:Genetic Testing; D007722:Health Knowledge, Attitudes, Practice; D006302:Health Services Research; D006801:Humans; D019303:Multilingualism; D011177:Postal Service; D011296:Prenatal Diagnosis; D011320:Primary Health Care; D012805:Sickle Cell Trait / Q000175:diagnosis; D011795:Surveys and Questionnaires; D013689:Telephone; D013789:Thalassemia / Q000175:diagnosis; D006113:United Kingdom; D014505:Urban Population