Does "no" mean "sometimes"? How older adults respond to the same depression symptoms with different response formats

In this report we describe problems associated with the administration of binary choice response questionnaires, with particular attention to depression measures given to older adults. A convenience sample of 77 respondents aged 70+ completed two different versions of the 8-item Center for Epidemiologic Studies-Depression (CES-D) scale. Versions were identical except for having either two- or four- response option formats. Within-person responses were compared to determine equivalence across formats. We found that a binary-response option format over- or under-estimated depressive symptomatology. Thus, a four-response option for the CES-D may be a more precise estimate of currently experienced symptoms.