Increasing the number of contacts generated during contact tracing interviews

To stem the spread of infectious diseases (e.g., Ebola), epidemiologists conduct contact tracing interviews (CTIs) with infected individuals regarding their contacts who may also be infected. These contact tracing interviews, however, may be vulnerable to deadly errors of omission. A promising technique to maximise recall is the Cognitive Interview (CI), which is grounded in psychological theory. In the present study, participants imagined they were infected with meningococcal meningitis and reported their contacts over the previous three days during either a control interview or a CI. To model the cognitive impairment associated with being sick, half of the participants were interviewed while simultaneously completing a cognitive impairment task. The CI generated more contacts than the control interview. However, when the cognitive impairment task was completed, the CI and the control interview performed similarly. We recommend the CI be considered as an alternative to the control interview, particularly if the interviewee is not temporarily impaired due to distraction or illness.