Estimating the memory bottleneck for contact tracing

The SARS-CoV-2 pandemic has highlighted the importance and challenges of contact tracing for epidemiological mitigation. One of these challenges is forgetting. Contact tracing interviews (CTIs) typically rely on human memory, which is prone to decline over time. A robust estimate of contact forgetting can inform epidemiological modelling and policies in the context of infectious diseases. Here we aim to quantify the typical contact forgetting function using panel data from age and gender representative participants from Germany and the UK, emulating 15.000 CTIs. We hypothesize that the number of remembered contacts will decline as a power function of recall delay and that this decline is steeper for older participants.

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 this decline for age- and gender-representative samples from the UK 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 diary. We further find that these factors interact with delay: Older subjects and those who made no use of memory aids have steeper memory decline functions. These findings can inform epidemiological modelling and policies in the context of infectious diseases.

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 this decline for age- and gender-representative samples from the UK 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 diary. We further find that these factors interact with delay: Older subjects and those who made no use of memory aids have steeper memory decline functions. These findings can inform epidemiological modelling and policies in the context of infectious diseases