title: A study of mail survey method.
abstract: A major disadvantage of the mail survey in medical research is non-response, which may introduce bias. This study measured the effect of two simple factors on the response rate to a questionnaire concerning headache and migraine in a survey of 2,508 electors. The two factors were the class of postage and the colour of envelopes used; neither was found to have a significant effect. It was concluded that cheaper mailing methods are not likely to jeopardise response.
mesh_terms: D003116:Color; D006261:Headache; D006306:Health Surveys; D006801:Humans; D008881:Migraine Disorders; D010678:Philately; D011177:Postal Service; D012106:Research; D011795:Surveys and Questionnaires; D006113:United Kingdom