Contact tracing indicators for COVID-19: Rapid scoping review and conceptual framework

  1. Florian Vogt
  2. Karishma Krishna Kurup
  3. Paul Mussleman
  4. Caroline Habrun
  5. Madeleine Crowe
  6. Alexandra Woodward
  7. Giovanna Jaramillo-Gutierrez
  8. John Kaldor
  9. Sirenda Vong
  10. Victor del Rio Vilas

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Abstract

Contact tracing is one of the key interventions in response to the COVID-19 pandemic but its implementation varies widely across countries. There is little guidance on how to monitor contact tracing performance, and no systematic overview of indicators to assess contact tracing systems or conceptual framework for such indicators exists to date.

Methods

We conducted a rapid scoping review using a systematic literature search strategy in the peer-reviewed and grey literature as well as open source online documents. We developed a conceptual framework to map indicators by type (input, process, output, outcome, impact) and thematic area (human resources, financial resources, case investigation, contact identification, contact testing, contact follow up, case isolation, contact quarantine, transmission chain interruption, incidence reduction).

Results

We identified a total of 153 contact tracing indicators from 1,555 peer-reviewed studies, 894 studies from grey literature sources, and 15 sources from internet searches. Two-thirds of indicators were process indicators (102; 67%), while 48 (31%) indicators were output indicators. Only three (2%) indicators were input indicators. Indicators covered seven out of ten conceptualized thematic areas, with more than half being related to either case investigation (37; 24%) or contact identification (44; 29%). There were no indicators for the input area “financial resources”, the outcome area “transmission chain interruption”, and the impact area “incidence reduction”.

Conclusions

Almost all identified indicators were either process or output indicators focusing on case investigation, contact identification, case isolation or contact quarantine. We identified important gaps in input, outcome and impact indicators, which constrains evidence-based assessment of contact tracing systems. A universally agreed set of indicators is needed to allow for cross-system comparisons and to improve the performance of contact tracing systems.

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  1. Version published to 10.1371/journal.pone.0264433
  2. ScreenIT

    SciScore for 10.1101/2021.05.13.21257067: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    While the search process included locating literature in the three core health sciences databases PubMed, Embase, and Cochrane Library, our search also relied heavily on grey literature sources.
    PubMed
    suggested: (PubMed, RRID:SCR_004846)
    Cochrane Library
    suggested: (Cochrane Library, RRID:SCR_013000)
    In addition, we searched the internet using various combinations of relevant search terms in the Google search engine.
    Google
    suggested: (Google, RRID:SCR_017097)
    The searches in PubMed, Cochrane, and Embase employed the use of both subject headings and natural language keywords.
    Cochrane
    suggested: (Cochrane Library, RRID:SCR_013000)
    The full search strings used in the PubMed, Embase, and Cochrane Library databases can be found in Supporting Information File 2.
    Embase
    suggested: (EMBASE, RRID:SCR_001650)
    Citations arising from all of searches were compiled in the citation management software EndNote v.X9 (11), and said software was used for detecting and removing duplicate citations.
    EndNote
    suggested: (EndNote, RRID:SCR_014001)

    Results from OddPub: Thank you for sharing your data.

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study was subject to several limitations. First, our search was restricted to English, thus documents in any other language would have been missed. Second, we restricted our search to the three known human coronaviruses with epidemic potential due to their similar epidemiological profiles. Contact tracing indicators for other epidemic-prone infectious diseases were thus missed. Third, we did not assess system-wide indicators, e.g. those relating to coordination across units and/or levels, or governance. Fourth, we were not able to record the total number of websites searched during our internet search, and could therefore only report the number of websites from which indicators were included for this study (see Figure 1). Fifth, it is possible that there is publication bias across indicator categories, with input indicators being underrepresented in published or online documents compared to process and output indicators due to perceived lower operational relevance by public health officials in charge of contact tracing systems. This might be particularly the case for indicators that are more relevant at peripheral levels of health systems compared to priorities at central levels. Sixth, though we applied a very systematic search strategy for the peer-reviewed and grey literature, this was not a full systematic review and therefore did not include or adhere to all items recommended for full systematic reviews (21). We did, however, follow existing guidance for the rapid co...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  3. Version published to 10.1101/2021.05.13.21257067v1 on medRxiv