Increasing the number of contacts generated during contact tracing interviews

Estimating the human bottleneck for contact tracing

The SARS-CoV-2 pandemic has highlighted the importance of contact tracing for epidemiological mitigation. Contact tracing interviews (CTIs) typically rely on episodic memory, which is prone to decline over time. Here, we provide a quantitative estimate of reporting decline for age- and gender-representative samples from the United Kingdom and Germany, emulating >15,000 CTIs. We find that the number of reported contacts declines as a power function of recall delay and is significantly higher for younger subjects and for those who used memory aids, such as a scheduler. We further find that these factors interact with delay: Older subjects and those who made no use of memory aids have steeper decline functions. These findings can inform epidemiological modeling and policies in the context of infectious diseases.

Efficacy of memory protocols in 9- to 89-year-olds' memory for prior contacts

Memory for prior contacts has several important applied implications, including contact tracing (for communicable diseases). Incomplete episodic memory reports, which occur across the developmental lifespan but are particularly relevant for children and older adults, may hamper such efforts. Prior research has shown that cognitively informed memory techniques may bolster recall of contacts in adults, but that work has not addressed the developmental efficacy of these techniques. Here we evaluated the effectiveness of such techniques for familiar and unfamiliar contacts within a sample of 9- to 89-year-olds in the context of an ongoing pandemic. The tested memory techniques bolstered recall across the lifespan, irrespective of whether the interview was conducted live with an interviewer or via a self-led interview. Children, emerging adults, and adults did not reveal any differences in memory productivity, however, older adults recalled fewer contacts. Implications for theory and application are discussed.

Enhancing the effectiveness of contact tracing interviews: A randomized controlled experiment of an enhanced cognitive interview protocol

OBJECTIVES

To compare the efficacy of a psychologically-based contact tracing interview protocol to a control protocol that emulated current practices under both interviewer-led and self-led modalities.

METHODS

This randomized controlled experiment utilized a 2 × 2 factorial design (Enhanced Cognitive protocol vs Control protocol; Interviewer-led call vs Self-led online survey). Data were collected online (n = 200; M_age = 44; 56.5% female; 79.5% White) during the COVID-19 pandemic (July 2, 2020 - September 15, 2020).

RESULTS

The Enhanced Cognitive protocol increased reported close contacts by 51% compared with the Control protocol (d = 0.44 [0.15, 0.71]). This effect was present for both interview modalities and for both identifiable and non-identifiable contacts. The Enhanced Cognitive protocol also increased both the quantity of person descriptors (d = 1.36 [0.87, 1.85]) and the utility of descriptions (r = 0.35 [0.13, 0.53]).

CONCLUSIONS

The application of cognitive principles in contact tracing interviews can significantly enhance the quantity and quality of information provided by respondents. Epidemiologists and public health investigators could benefit from utilizing cognitive principles and self-led modalities in contact tracing interviews.