Core outcome measurement instruments for use in clinical and research settings for adults with post-COVID-19 condition: an international Delphi consensus study

Post-COVID-19 condition (also known as long COVID) is a new, complex, and poorly understood disorder. A core outcome set (COS) for post-COVID-19 condition in adults has been developed and agreement is now required on the most appropriate measurement instruments for these core outcomes. We conducted an international consensus study involving multidisciplinary experts and people with lived experience of long COVID. The study comprised a literature review to identify measurement instruments for the core outcomes, a three-round online modified Delphi process, and an online consensus meeting to generate a core outcome measurement set (COMS). 594 individuals from 58 countries participated. The number of potential instruments for the 12 core outcomes was reduced from 319 to 19. Consensus was reached for inclusion of the modified Medical Research Council Dyspnoea Scale for respiratory outcomes. Measures for two relevant outcomes from a previously published COS for acute COVID-19 were also included: time until death, for survival, and the Recovery Scale for COVID-19, for recovery. Instruments were suggested for consideration for the remaining nine core outcomes: fatigue or exhaustion, pain, post-exertion symptoms, work or occupational and study changes, and cardiovascular, nervous system, cognitive, mental health, and physical outcomes; however, consensus was not achieved for instruments for these outcomes. The recommended COMS and instruments for consideration provide a foundation for the evaluation of post-COVID-19 condition in adults, which should help to optimise clinical care and accelerate research worldwide. Further assessment of this COMS is warranted as new data emerge on existing and novel measurement instruments

Core outcome measurement set for research and clinical practice in post COVID-19 condition (long COVID) in children and young people: an international Delphi consensus study "PC-COS Children"

The COVID-19 pandemic substantially impacted different age groups, with children and young people (CYP) not exempted. Many have experienced enduring health consequences. Presently, there is no consensus on the health outcomes to assess in CYP with post COVID-19 condition. Furthermore, it is unclear which measurement instruments are appropriate for use in research and clinical management of CYP with post-COVID-19. To address these unmet needs, we conducted a consensus study, aiming to develop a core outcome set (COS) and an associated core outcome measurement set (COMS) for evaluating post-COVID-19 condition in CYP. Our methodology comprised of two phases. In phase 1 (to create a COS), we performed an extensive literature review and categorisation of outcomes, and prioritised those outcomes in a two-round online modified Delphi process followed by a consensus meeting. In phase 2 (to create the COMS), we performed another modified Delphi consensus process to evaluate measurement instruments for previously defined "core outcomes" from phase 1, followed by an online consensus workshop to finalise recommendations regarding the most appropriate instruments for each core outcome. In phase 1, 214 participants from 37 countries participated, with 154 (72%) contributing to both Delphi rounds. The subsequent online consensus meeting resulted in a final COS which encompassed seven critical outcomes: fatigue; post-exertion symptoms; work/occupational and study changes; as well as functional changes, symptoms, and conditions relating to cardiovascular, neuro-cognitive, gastrointestinal, and physical outcomes. In phase 2, 11 international experts were involved in a modified Delphi process, selecting measurement instruments for a subsequent online consensus workshop where 30 voting participants discussed and independently scored the selected instruments. As a result of this consensus process, four instruments met a priori consensus criteria for inclusion: "PedsQL multidimensional Fatigue scale" for "fatigue"; "PedsQL Gastrointestinal symptom scales" for "gastrointestinal"; "PedsQL Cognitive Functioning Scale" for "Neuro-cognitive" and "EQ5D family" for "physical functioning". Despite proposing outcome measurement instruments for the remaining three core outcomes ("cardiovascular", "post-exertional malaise", "work/occupational and study changes"), a consensus was not achieved. Our international, consensus-based initiative presents a robust framework for evaluating post-COVID-19 condition in CYP in research and clinical practice via a rigorously defined COS and associated COMS. It will aid in the uniform measurement and reporting of relevant health outcomes worldwide

Core Outcome Measurement Set for Research and Clinical Practice in Post COVID-19 Condition (Long COVID) in Children and Young People: An International Delphi Consensus Study "PC-COS Children"

The COVID-19 pandemic substantially impacted different age groups, with children and young people (CYP) not exempted. Many have experienced enduring health consequences. Presently, there is no consensus on the health outcomes to assess in CYP with post COVID-19 condition. Furthermore, it is unclear which measurement instruments are appropriate for use in research and clinical management of CYP with post-COVID-19. To address these unmet needs, we conducted a consensus study, aiming to develop a core outcome set (COS) and an associated core outcome measurement set (COMS) for evaluating post-COVID-19 condition in CYP. Our methodology comprised of two phases. In phase 1 (to create a COS), we performed an extensive literature review and categorisation of outcomes, and prioritised those outcomes in a two-round online modified Delphi process followed by a consensus meeting. In phase 2 (to create the COMS), we performed another modified Delphi consensus process to evaluate measurement instruments for previously defined "core outcomes" from phase 1, followed by an online consensus workshop to finalise recommendations regarding the most appropriate instruments for each core outcome. In phase 1, 214 participants from 37 countries participated, with 154 (72%) contributing to both Delphi rounds. The subsequent online consensus meeting resulted in a final COS which encompassed seven critical outcomes: fatigue; post-exertion symptoms; work/occupational and study changes; as well as functional changes, symptoms, and conditions relating to cardiovascular, neuro-cognitive, gastrointestinal, and physical outcomes. In phase 2, 11 international experts were involved in a modified Delphi process, selecting measurement instruments for a subsequent online consensus workshop where 30 voting participants discussed and independently scored the selected instruments. As a result of this consensus process, four instruments met a priori consensus criteria for inclusion: "PedsQL multidimensional Fatigue scale" for "fatigue"; "PedsQL Gastrointestinal symptom scales" for "gastrointestinal"; "PedsQL Cognitive Functioning Scale" for "Neuro-cognitive" and "EQ5D family" for "physical functioning". Despite proposing outcome measurement instruments for the remaining three core outcomes ("cardiovascular", "post-exertional malaise", "work/occupational and study changes"), a consensus was not achieved. Our international, consensus-based initiative presents a robust framework for evaluating post-COVID-19 condition in CYP in research and clinical practice via a rigorously defined COS and associated COMS. It will aid in the uniform measurement and reporting of relevant health outcomes worldwide