title: Prenotification had no additional effect on the response rate and survey quality: a randomized trial.
abstract: OBJECTIVE
  To determine the effect of prenotification package on survey quality, including response rates, response time, percentage of nonresponse items, and cost.
  
  
  METHODS
  Participants were randomized into two groups. In the first round mailing, participants in prenotification group received a prenotification package, whereas direct questionnaire mailing group participants received a questionnaire with prepaid return envelope only. In the second round mailing, both groups received the questionnaires. The trial was integrated into a study among 35-65-year-old female nurses in Hong Kong.
  
  
  RESULTS
  A total of 367 nurses were included in the trial. A total of 362 mails were successfully delivered. The initial response rate in the first round mailing were 8.79% and 8.89% for prenotification and direct questionnaire mailing groups, respectively. After the second round mailing, the final response rate in prenotification and direct questionnaire mailing groups were 17.58% and 17.22%, respectively; no significant difference was found between the groups. There were no differences with respect to percentage of nonresponse items or response time, but the cost of prenotification group was HK$ 15.11 per response higher than direct mailing group.
  
  
  CONCLUSIONS
  Prenotification had no additional effect on the response rate and other survey quality compared with direct questionnaire mailing in a Hong Kong population.
authors.affiliation: Department of Community Medicine, School of Public Health, The University of Hong Kong, 3/F William M.W. Mong Block, 21 Sassoon Road, Pokfulam, Hong Kong. Electronic address: yjxie@hku.hk.
authors.forename: Yaojie
authors.initials: Y
authors.lastname: Xie
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Ho
mesh_terms: D000328:Adult; D000368:Aged; D003256:Community Participation / Q000706:statistics & numerical data*; D003625:Data Collection / Q000379:methods* / Q000592:standards*; D005260:Female; D006723:Hong Kong; D006801:Humans; D008875:Middle Aged; D009726:Nurses; D011177:Postal Service; D011795:Surveys and Questionnaires
keywords: Hong Kong population; Mail survey; Prenotification; Randomized trial; Response rate; Response time