You posted:
> Dear list,
> I am looking for literature about critical appraisal of questionnaire
> surveys especially for the problems with non-respondents (nonresponse
> bias).
> I've heard that the JAMA only accepts surveys with a response-rate of >=
> 60%. But I could not find such a minimum rate in the literature
> (searched 3 survey research textbooks and 2 clinical epidemiology
> textbooks).
>
> Three questions:
> Is there any evidence for such a minimum rate or is it "only" a
> convention like a p-value of 0,05?
> If it is a convention is anyone aware of refernces about it?
> Is such a minimum rate reasonable?
The answer to your three questions is yes, yes, and yes. For a good
discussion of the impact of nonresponse rates on width of confidence
intervals, as well as appropriate strategies, see pp. 359-63 in William
Cochran's Sampling Techniques (3rd edition, 1977, John Wiley & Sons).
Surveys often ignore implications of non-response; however, at response
rates below 60-70% there are distinct problems with width of adjusted
confidence intervals becoming excessive relative to precision required for
decisions, as well as increasing potential for self-selection bias to
distort conclusions.
David Birnbaum, PhD, MPH
Clinical Assistant Professor
Dept. of Health Care & Epidemiology
University of British Columbia, Canada
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