Personality disorders in older adults: expert opinion as a first step toward evaluating the criterion validity of an informant questionnaire (HAP)

There is a lack of questionnaires for screening personality disorders (PD) in older adults. The development of measurement instruments is hampered because the criteria of DSM-IV-TR PD are not age-neutral which might lead to over- and underdiagnosis. The HAP is specifically developed for use in geriatric settings. In this Delphi-study, a panel of experts examined two research questions: (1) To what extend are the items of the HAP age-neutral?; (2) Does the HAP detect PD's of DSM-IV-TR, based on qualitative research?
At first the experts judged both the age neutrality of every HAP item and the semantic resemblance with the criteria of PD's. Next the results and the individual explanations were anonymously presented. Agreement with an HAP item and the proposed DSM criterion was rated on a scale from 0 (full rejection) to 10 (full acceptance).
The experts labeled all items as age neutral and the HAP represented sufficient criteria for 9 of the 10 DSM-IV-TR PD's. Only schizotypal PD was not represented. These initial results are promising, however the potential of the HAP to screen for PDs in young and older adults should be further empirically explored. The age neutrality of the HAP items is a hypothesis to be tested in follow-up research by for instance differential item functioning (DIF) analysis, followed by research regarding the criterion validity in (non) clinical samples of older adults.