The purpose of this study was to assess changes in diabetes management and healthcare utilisation among First Nations with diabetes in Alberta before and during the COVID-19 pandemic.

This analysis used a retrospective cohort in a case–control design. Individual-level administrative health datasets (1 April 2018 to 31 March 2022) were linked and data were formatted as a segmented interrupted time series.

This study took place in Alberta, Canada using administrative data.

Adult First Nations and non-First Nations (matched 1:1) with diabetes and living in Alberta were included (n=28 101; 53% female, 47% male).

The primary outcome was the change in incidence rate of general practitioner (GP) visits, emergency department (ED) visits, hospitalisations and diabetes-related drug dispenses during-COVID-19 versus pre-COVID-19, quantified using generalised linear regressions. The secondary outcome was to report the reasons for non-drug outcomes pre-COVID-19 and during-COVID-19, based on primary diagnosis International Statistical Classification of Diseases and Related Health Problems codes.

Pre-COVID-19, baseline rates of GP visits, ED visits, hospitalisations and drug dispenses were significantly higher among First Nations compared with non-First Nations (rate differences 398.32 (391.97–404.67), 100.58 (98.32–102.84), 14.49 (13.56–15.43), 876.98 (868.72–885.24) per 100 person-years (PY); p

Healthcare utilisation was substantially elevated among First Nations compared with non-First Nations peoples before and during COVID-19. While the generalisability of our findings to other health systems and populations may be limited, our findings are clinically applicable among First Nations across Alberta in order to help direct public health programming post-COVID-19.