Table 1 Search Terms and Boolean Combinations for Each Database

PubMed

(“COVID-19” OR “SARS-CoV-2” OR “coronavirus disease 2019”) AND (“Type 2 Diabetes Mellitus” OR “T2DM” OR “diabetes”) AND (“mortality” OR “severity” OR “ICU admission” OR “mechanical ventilation” OR “complications”)

January 18, 2024

Scopus

TITLE-ABS-KEY (“COVID-19” OR “SARS-CoV-2”) AND (“Type 2 Diabetes Mellitus” OR “T2DM”) AND (“mortality” OR “severity” OR “critical illness” OR “hospitalization”)

February 5, 2024

Web of Science

TS = (“COVID-19” OR “SARS-CoV-2”) AND TS = (“Type 2 Diabetes Mellitus” OR “T2DM”) AND TS = (“mortality” OR “mechanical ventilation” OR “ARDS”)

November 22, 2023

Embase

(‘COVID-19’/exp OR ‘SARS-CoV-2’/exp) AND (‘Type 2 diabetes mellitus’/exp OR ‘T2DM’/exp) AND (‘mortality’/exp OR ‘hospitalization’/exp OR ‘mechanical ventilation’/exp)

December 14, 2023

Cochrane Library

(“COVID-19” OR “SARS-CoV-2”) AND (“Type 2 Diabetes Mellitus” OR “T2DM”) AND (“mortality” OR “ICU admission” OR “disease severity”)

October 3, 2023

Google Scholar

(“COVID-19” AND “Type 2 Diabetes Mellitus” AND “mortality”) OR (“SARS-CoV-2” AND “T2DM” AND “complications”) – Limited to title and first 200 results

March 1, 2024

ClinicalTrials.gov

(“COVID-19” OR “SARS-CoV-2”) AND (“Type 2 Diabetes Mellitus” OR “T2DM”) – Filtered for completed and ongoing studies

January 30, 2024

MEDLINE

(“COVID-19”[MeSH] OR “SARS-CoV-2”[MeSH]) AND (“Type 2 Diabetes Mellitus”[MeSH] OR “T2DM”[MeSH]) AND (“mortality”[MeSH] OR “severity”[MeSH] OR “hospitalization”[MeSH])

February 12, 2024