Stuart J McGurnaghan, Amanda Weir, Jen Bishop, Sharon Kennedy, Luke A K Blackbourn, David A McAllister, Sharon Hutchinson, Thomas M Caparrotta, Joseph Mellor, Anita Jeyam, Joseph E O'Reilly, Sarah H Wild, Sara Hatam, Andreas Höhn, Marco Colombo, Chris Robertson, Nazir Lone, Janet Murray, Elaine Butterly, John Petrie, Brian Kennon, Rory McCrimmon, Robert Lindsay, Ewan Pearson, Naveed Sattar, John McKnight, Sam Philip, Andrew Collier, Jim McMenamin, Alison Smith-Palmer, David Goldberg, Paul M McKeigue, Helen M Colhoun, Alice Whettlock, Allan McLeod, Andrew Gasiorowski, Andrew Merrick, Andy McAuley, April Went, Calum Purdie, Colin Fischbacher, Colin Ramsey, David Bailey, David Henderson, Eisin McDonald, Genna Drennan, Graeme Gowans, Graeme Reid, Heather Murdoch, Jade Carruthers, Josie Murray, Karen Heatlie, Lorraine Donaldson, Martin Paton, Martin Reid, Melissa Llano, Michelle Murphy-Hall, Ross Hall, Ross Cameron, Susan Brownlie, Adam Gaffney, Aynsley Milne, Christopher Sullivan, Edward McArdle, Elaine Glass, Johanna Young, William Malcolm, Jodie McCoubrey, University of St Andrews. School of Geography & Sustainable Development, and University of St Andrews. School of Medicine
SHu reports grants from Health Protection Scotland during the conduct of the study. TMC reports grants from Diabetes UK (18/0005786). CR reports grants from Public Health Scotland and UK Research and Innovation. Background We aimed to ascertain the cumulative risk of fatal or critical care unit-treated COVID-19 in people with diabetes and compare it with that of people without diabetes, and to investigate risk factors for and build a cross-validated predictive model of fatal or critical care unit-treated COVID-19 among people with diabetes. Methods In this cohort study, we captured the data encompassing the first wave of the pandemic in Scotland, from March 1, 2020, when the first case was identified, to July 31, 2020, when infection rates had dropped sufficiently that shielding measures were officially terminated. The participants were the total population of Scotland, including all people with diabetes who were alive 3 weeks before the start of the pandemic in Scotland (estimated Feb 7, 2020). We ascertained how many people developed fatal or critical care unit-treated COVID-19 in this period from the Electronic Communication of Surveillance in Scotland database (on virology), the RAPID database of daily hospitalisations, the Scottish Morbidity Records-01 of hospital discharges, the National Records of Scotland death registrations data, and the Scottish Intensive Care Society and Audit Group database (on critical care). Among people with fatal or critical care unit-treated COVID-19, diabetes status was ascertained by linkage to the national diabetes register, Scottish Care Information Diabetes. We compared the cumulative incidence of fatal or critical care unit-treated COVID-19 in people with and without diabetes using logistic regression. For people with diabetes, we obtained data on potential risk factors for fatal or critical care unit-treated COVID-19 from the national diabetes register and other linked health administrative databases. We tested the association of these factors with fatal or critical care unit-treated COVID-19 in people with diabetes, and constructed a prediction model using stepwise regression and 20-fold cross-validation. Findings Of the total Scottish population on March 1, 2020 (n=5 463 300), the population with diabetes was 319 349 (5·8%), 1082 (0·3%) of whom developed fatal or critical care unit-treated COVID-19 by July 31, 2020, of whom 972 (89·8%) were aged 60 years or older. In the population without diabetes, 4081 (0·1%) of 5 143 951 people developed fatal or critical care unit-treated COVID-19. As of July 31, the overall odds ratio (OR) for diabetes, adjusted for age and sex, was 1·395 (95% CI 1·304–1·494; p