Prenotification had no additional effect on the response rate and survey quality: a randomized trial

ObjectivesTo determine the effect of prenotification package on survey quality, including response rates, response time, percentage of nonresponse items, and cost.Study Design and SettingParticipants 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.ResultsA 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.ConclusionPrenotification had no additional effect on the response rate and other survey quality compared with direct questionnaire mailing in a Hong Kong population.