Investigating people’s lifetime history of suicide attempts: a roadmap for studying interviewer-related error

It is critically important to correctly identify persons with a lifetime history (LTH) of suicide attempts (SA) from both a clinical and research perspective. Face-to-face interviews are often the best available method for researchers to collect data about a complex phenomenon like a LTH of SA. However, extensive survey methodology research has shown that probing sensitive topics like a LTH of SA are sensitive for interviewer-related errors or interviewer effects. Studies investigating these interviewer effects are scarce in the field of suicide studies. This study presents a possible roadmap for study of interviewerrelated measurement error and an exploration of role-dependent behaviour of interviewers by assessing the LTH of SA through an epidemiological design. Data from the baseline assessment of the Netherlands Study of Depression and Anxiety (N = 2981) was used to illustrate the proposed roadmap to study interviewer effects. Results show: : (1) that it was possible to identify the existence of interviewer effects in assessing a LTH of SA; (2) that interviewer effects occurred by probing and clarification activities of the interviewer but not with inadequate formulation of the original question and so give a possible explanation for these effects; and (3) that it was possible to study the impact of these effects on the association between a well-known risk factor and LTH of SA. Applying the Measurement Error framework for systematically examining errors in data collection on suicidality seems a promising method.