Losses in follow-up that are biased with respect to outcome invalidate the results. There are many ways of dealing with non-response in follow-up studies. Three separate methods were used to investigate a potential bias in a mail survey of 2471 disabled people. At a response rate of 84%, the non-respondents were significantly different from the respondents with respect to the outcome, return to work and vocational training. The success rate in terms of the outcome was negatively related to the number of reminders. Significant differences were found in response rates according to age, social class, impairments, previous employment record, and completion of rehabilitation courses. There is no safe level of response rates below 100%. However small the non-response, a possible bias as a result of it must be investigated.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.