BackgroundFrench health authorities recommend the testing of HbA1c every 3 to 6 months in patients with diabetes. The successive containments linked to the SARSCoV-2 pandemic may have had a profound impact on the follow-up of diabetic patients in primary care. The objective of this study was to investigate the effect of containments on the volume of HbA1c assays and on HbA1c values of type 2 diabetic patients monitored in primary care in Northern France compared to usual seasonal variations. MethodsEpidemiological study of a multicentre retrospective cohort, collecting the number and the value of HbA1c assays from type 2 diabetic patients, carried out in 73 private medical analysis laboratories in Northern France region between October 1, 2018 and October 31, 2022. ResultsA total of 196,744 patients and 828,037 tests were included. The first and third containments were associated with a significant decrease in the mean number of performed HbA1c tests, the decrease in the 2nd containment did not reach significance. We observed a significant decrease in HbA1c testing during the winter holiday season and the summer months. The variations in HbA1c values were not substantial compared to seasonal variations.