Differences in HbA 1C at the time of diabetes diagnosis in the adult population of Ontario, Canada.

AIMS: To determine the proportion of adults with HbA1c ≥8.0% (64mmol/mol) at diabetes diagnosis, as an indicator of delayed diagnosis or less intensive screening.

METHODS: We conducted a cross-sectional population-level study using clinical, administrative and immigration data from Ontario, Canada. We identified all individuals diagnosed with diabetes between June 2012 and June 2015, and determined the HbA1c between 60days prior to and 30days after diagnosis. Individuals were stratified based on many sociodemographic, clinical and primary care characteristics, and the proportion with HbA1c ≥8.0% (64mmol/mol) was determined.

RESULTS: Mean HbA1c at diabetes diagnosis in the population was 7.3±1.9% (56±21mmol/mol), and 21.1% had HbA1c ≥8.0% (64mmol/mol) at diagnosis. Factors for which there were important differences in the proportion with HbA1c ≥8.0% (64mmol/mol) included age, sex, ethnicity, comorbidities, frequency of primary care and primary care rostering.

CONCLUSIONS: In a real-world population-level setting, more than one-fifth of individuals diagnosed with diabetes have HbA1c levels ≥8.0% (64mmol/mol), suggesting a delay in diagnosis due to inadequate screening. Differences were found based on age, sex and clinical factors, but not based on socioeconomic or immigration factors.