Do postage-stamps increase response rates to postal surveys? A randomized controlled trial

Postal health surveys in the general population can provide important information to assist with planning and service provision. 1 High response rates are needed to ensure validity and to minimize costs from following-up non-responders. 2 Only a small number of studies have examined methods to increase response rates in postal surveys. Using a post-office stamp rather than a pre-paid business reply envelope may seem more personal and encourage participants to return the questionnaire. However, results from trials evaluating this are inconsistent and limited to health professionals in North America. 3-5 Consequently there is little evidence to inform the choice of reply envelopes in postal surveys of the general UK population. This was determined in the current study.