COVID-19-related morbidity and mortality in people with multiple long-term conditions: a systematic review and meta-analysis of over 4 million people.

Objectives: To describe the direct impact of coronavirus disease 2019 (COVID-19) infection on morbidity and mortality in people with multiple long-term conditions (MLTCs).

Design: A systematic review and meta-analysis including observational studies.

Setting: Studies conducted between 1 January 2020 and 4 May 2023 across 51 countries were identified from five databases.