We evaluated the long-term efficacy of CSII in a cohort of adult patients with type 1 diabetes. SUBJECTS AND METHODS: This was a retrospective observational study of 200 patients with type 1 diabetes who initiated CSII at a single outpatient clinic in Kingston, ON, Canada between January 1998 and December 2012. Data were collected from 3 months prior to and up to 15 years after initiation of CSII and included glycated hemoglobin (HbA1c) level and demographic factors potentially associated with glycemic control. RESULTS: Mean age and duration of diabetes at CSII initiation were 35.4 years and 22.4 years, respectively.