Low reporting quality limits the contribution of human organ models to COVID-19 research: a systematic review

BACKGROUND: The COVID-19 pandemic created a unique situation in which researchers repurposed human models of varying complexity to investigate SARS-CoV-2, providing the opportunity to analyse their contribution across organs. METHODS: We conducted a systematic review of 558 studies, divided into pandemic and post-pandemic periods, to assess how human models were applied to investigate host factors, viral replication of SARS-CoV-2, immune responses, and to evaluate reporting quality. FINDINGS: Our analysis revealed substantial limitations that were only partially alleviated in post-pandemic studies. These limitations included heterogeneity of outcome measures, incomplete documentation of model characteristics and experimental procedures, and variable reporting quality, which were associated with reduced cross-study comparability, more difficult risk-of-bias assessment, and limited reliability and interpretability of evidence synthesis and meta-analytical results. INTERPRETATION: Strengthening community-driven reporting standards and methodological transparency is essential to enable robust evidence synthesis and to fully realise the potential of human organ models in future pandemics and translational research.