Factors associated with early insulin initiation in Type 2 diabetes: a Canadian cross-sectional study

To examine the patient characteristics associated with early initiation of insulin after a diagnosis of Type 2 diabetes.

We analysed cross-sectional data from the 2012 Canadian Community Health Survey conducted by Statistics Canada. Multivariable logistic regression was used to explore the association between patient sociodemographic and health status characteristics and initiating insulin within 1 year of a diagnosis of Type 2 diabetes (early insulin use).

Weighted estimates for the Canadian population showed that 32% of patients with Type 2 diabetes initiated insulin within 1 year of their diagnosis. Of the insulin initiators, 52% were female and 68% were aged ≥60 years. Factors strongly associated with early initiation of insulin were age (60-69 years: adjusted odds ratio 1.89, 95% CI 1.84-1.94; ≥ 70 years, odds ratio 2.08, 95% CI 2.01-2.15, both vs 40-49 years); smoking (smoker vs never: odds ratio 2.39, 95% CI 2.32-2.46); geography (Western Canada: odds ratio 2.75, 95% CI 2.69-2.81; Quebec: odds ratio 2.20, 95% CI 2.13-2.27, both vs Ontario); mental health (poor vs excellent: odds ratio 1.98, 95% CI 1.92-2.04); BMI (overweight vs normal/underweight: odds ratio 1.63, 95% CI 1.58-1.67); oral antidiabetic medication use (yes vs no: odds ratio 0.66, 95% CI 0.65-0.68); and alcohol use (regular vs non-drinker: odds ratio 0.66, 95% CI 0.65-0.68).

One-third of the study population with Type 2 diabetes initiated insulin within their first year of diagnosis. Age, smoking status, geographical location, mental health, BMI, education, oral antidiabetic medication use, employment, physical activity, language, doctor visits and alcohol consumption were associated with timing of insulin initiation.