Response rates to postal questionnaires can be increased

Clinical question: 
How can response rates to postal questionnaires be increased?
Bottom line: 
Response rates to postal questionnaires can be increased by contacting people before they are sent the questionnaire. Questionnaires should be sent by first-class post or recorded delivery, and a stamped-return envelope provided. Questionnaires and letters should be maybe personal, and kept short. Incentives should be offered (preferably a small amount of money), and one or more reminders should be sent with a copy of the questionnaire to people who do not reply.
The odds of response were reduced when the questionnaire included questions of a sensitive nature, when questionnaires began with the most general questions or when participants were offered an opportunity to opt out of the study.
Postal questionnaires are widely used for data collection in epidemiological studies but non-response can reduce effective sample size and can introduce a bias. Finding ways of increasing response rates would improve the quality of health research.
Review CD#: 
May, 2007
Authored by: 
Brian R McAvoy