Controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire.
Mailed questionnaires are an economical method of data collection for epidemiologic studies, but response tends to be lower than for telephone or personal interviews. As part of a follow-up study of volunteers who provided a brief health history and blood sample for a blood specimen bank in 1989, the authors conducted a controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire. Interventions tested included variations on length of the questionnaire, effect of a monetary incentive, and effect of a postcard reminder versus a letter accompanied by a second questionnaire. Response was similar for the short (16-item, 4-page) and long (76-item, 16-page) questionnaire groups. The non-monetary [corrected] incentive did not improve the frequency of response. The second mailing of a questionnaire was significantly better than a postcard reminder in improving responses (23% vs. 10%). It is important to systematically test marketing principles to determine which techniques are effective in increasing response to mailed questionnaires for epidemiologic studies.
Hoffman
S C
SC
Department of Epidemiology, School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, MD, USA.
Burke
A E
AE
Helzlsouer
K J
KJ
Comstock
G W
GW
D000293:Adolescent; D000328:Adult; D000368:Aged; D001782:Blood Donors / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006302:Health Services Research / Q000379:methods*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D009042:Motivation; D010865:Pilot Projects; D011177:Postal Service; D017010:Reminder Systems; D012189:Retrospective Studies; D011795:Surveys and Questionnaires / Q000592:standards