Direct and indirect evidence of efficacy and safety of rapid exercise tests for exertional desaturation in Covid-19: a rapid systematic review

  1. Asli Kalin
  2. Babak Javid
  3. Matthew Knight
  4. Matt Inada-Kim
  5. Trisha Greenhalgh

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Abstract

Background

Even when resting pulse oximetry is normal in the patient with acute Covid-19, hypoxia can manifest on exertion. We summarise the literature on the performance of different rapid tests for exertional desaturation and draw on this evidence base to provide guidance in the context of acute Covid-19.

Main research questions

  • What exercise tests have been used to assess exertional hypoxia at home or in an ambulatory setting in the context of Covid-19 and to what extent have they been validated?

  • What exercise tests have been used to assess exertional hypoxia in other lung conditions, to what extent have they been validated and what is the applicability of these studies to acute Covid-19?

    • Method

    AMED, CINAHL, EMBASE MEDLINE, Cochrane and PubMed using LitCovid, Scholar and Google databases were searched to September 2020. Studies where participants had Covid-19 or another lung disease and underwent any form of exercise test which was compared to a reference standard were eligible. Risk of bias was assessed using QUADAS 2. A protocol for the review was published on the Medrxiv database.

    Results

    Of 47 relevant papers, 15 were empirical studies, of which 11 described an attempt to validate one or more exercise desaturation tests in lung diseases other than Covid-19. In all but one of these, methodological quality was poor or impossible to fully assess. None had been designed as a formal validation study (most used simple tests of correlation). Only one validation study (comparing a 1-min sit-to-stand test [1MSTST] with reference to the 6-min walk test [6MWT] in 107 patients with interstitial lung disease) contained sufficient raw data for us to calculate the sensitivity (88%), specificity (81%) and positive and negative predictive value (79% and 89% respectively) of the 1MSTST. The other 4 empirical studies included two predictive studies on patients with Covid-19, and two on HIV-positive patients with suspected pneumocystis pneumonia. We found no studies on the 40-step walk test (a less demanding test that is widely used in clinical practice to assess Covid-19 patients). Heterogeneity of study design precluded meta-analysis.

    Discussion

    Exertional desaturation tests have not yet been validated in patients with (or suspected of having) Covid-19. A stronger evidence base exists for the diagnostic accuracy of the 1MSTST in chronic long-term pulmonary disease; the relative intensity of this test may raise safety concerns in remote consultations or unstable patients. The less strenuous 40-step walk test should be urgently evaluated.

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    1. Version published to 10.1186/s13643-021-01620-w
    2. ScreenIT

      SciScore for 10.1101/2020.10.31.20223453: (What is this?)

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

      Table 1: Rigor

      NIH rigor criteria are not applicable to paper type.

      Table 2: Resources

      Software and Algorithms
      SentencesResources
      The second search will covered the following databases: AMED, CINAHL, EMBASE MEDLINE, and PubMed using the over-arching question ‘Very short exercise desaturation tests for use in the emergency department’.
      EMBASE
      suggested: (EMBASE, RRID:SCR_001650)
      PubMed
      suggested: (PubMed, RRID:SCR_004846)
      Search terms are: The third search will involve searching the Cochrane Database of Systematic Reviews (CDSR), the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane COVID-19 study register.
      Cochrane Database of Systematic Reviews
      suggested: None
      Cochrane Central Register of Controlled Trials
      suggested: (Cochrane Central Register of Controlled Trials, RRID:SCR_006576)
      Search of Cochrane Library - Issue 10 of 12, October 2020: Search of Cochrane COVID-19 study register: Our inclusion criteria used the PICOS/T frameworks as follows: No other limitations are imposed on the search or study selection process.
      Cochrane Library
      suggested: (Cochrane Library, RRID:SCR_013000)

      Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

      Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

      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.

      About SciScore

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    3. Version published to 10.21203/rs.3.rs-105883/v2 on Research Square
    4. Version published to 10.21203/rs.3.rs-105883/v1 on Research Square
    5. Version published to 10.1101/2020.10.31.20223453v1 on medRxiv