biostudies-literatureUnknown38(3)Pozo-Martin FRobert Koch-InstitutContact tracing is a non-pharmaceutical intervention (NPI) widely used in the control of the COVID-19 pandemic. Its effectiveness may depend on a number of factors including the proportion of contacts traced, delays in tracing, the mode of contact tracing (e.g. forward, backward or bidirectional contact training), the types of contacts who are traced (e.g. contacts of index cases or contacts of contacts of index cases), or the setting where contacts are traced (e.g. the household or the workplace). We performed a systematic review of the evidence regarding the comparative effectiveness of contact tracing interventions. 78 studies were included in the review, 12 observational (ten ecological studies, one retrospective cohort study and one pre-post study with two patient cohorts) and 66 mathEuropean journal of epidemiology243-266https://www.ebi.ac.uk/biostudies/studies/S-EPMC9932408biostudies-literatureComparative effectiveness of contact tracing interventions in the context of the COVID-19 pandemic: a systematic review.PMC9932408Diaconu VPozo-Martin FEl Bcheraoui CBeltran Sanchez MAMuller SAWeil KfalseComparative effectiveness of contact tracing interventions in the context of the COVID-19 pandemic: a systematic review.Contact tracing is a non-pharmaceutical intervention (NPI) widely used in the control of the COVID-19 pandemic. Its effectiveness may depend on a number of factors including the proportion of contacts traced, delays in tracing, the mode of contact tracing (e.g. forward, backward or bidirectional contact training), the types of contacts who are traced (e.g. contacts of index cases or contacts of contacts of index cases), or the setting where contacts are traced (e.g. the household or the workplace). We performed a systematic review of the evidence regarding the comparative effectiveness of contact tracing interventions. 78 studies were included in the review, 12 observational (ten ecological studies, one retrospective cohort study and one pre-post study with two patient cohorts) and 66 math2023-01-01T00:00:00Z2023 Mar2025-05-29T19:43:33.753Z2025-05-29T19:43:33.753ZS-EPMC99324083679534910.1007/s10654-023-00963-z