New CaDDI/POLYMOD hybrid instrument for use in the modelling of infection.

Using the original CaDDI instrument we collected 5 waves of time use diary data across the pandemic period in the UK, including during 3 'lockdowns' and 2 periods of relaxation of restrictions, plus a 2016 baseline (data available from the UKDS core collection, study number 8741).  

Since then, inspired by the 'contact' diaries used for modelling purposes by epidemiologists, we have designed a version of the CaDDI which includes more information on crowding while doing particular activities, or in particular venues, and the age/sex and degree of contact with people respondents report as being 'with them' across their diary days.  The idea is to combine the detailed information on activities of the time use diary (as well as information on location and social interaction) with variables of interest in epidemiological studies in respect of crowding and social contact (as in the POLYMOD 'diary').

For example, those reporting using public transport, or at work indoors, or in other indoor venues other than home or work, are asked to estimate how many others were within 3-4 metres of them.  For those reported as being 'with' during activities, sex and age group information is sought, as well as whether contact involved: kissing/hugging; touching hands; no physical contact but within 2 metres; or outside 2 metres.

The end result is data combining the detailed record of the time use diary with the sort of information used by epidemiologists for the modelling of infection, adding information on activities and location to information on social and physical contact.  The data will inform us not just about who people interacted with, but where they met them, and in what activity context.  

In addition, a technological innovation is that the new tool adapts automatically to screen size, changing to a vertical scrolling mode for use on smartphones and tablets.  This new instrument is currently in the field, with 1,000 diaries due to be collected from a quota representative national UK sample.  The data is expected to arrive within the next couple of weeks.

Links to instructional videos: