Defining a Childhood Type 1 Diabetes Cohort, Clinical Practice Measures, and Outcomes Within Administrative Data in British Columbia.

OBJECTIVE:We used administrative data to 1) establish a cohort of individuals with childhood-onset type 1 diabetes (T1D) in British Columbia (BC), and 2) define T1D-related clinical practice measures. METHODS:We applied a validated diabetes case-finding definition and differentiating algorithm to linked administrative data (1992-1993 to 2019-2020). Cases were removed when they did not meet inclusion criteria for childhood-onset T1D. Clinical practice measures were defined based on clinical practice guidelines. RESULTS:We developed an administrative cohort that included 5,901 individuals with childhood-diagnosed T1D between April 1, 1996, and March 31, 2020. The mean age was 22.31 (standard deviation 8.21) years. Clinical practice measures derived included diabetes outpatient visits (N=4,935) and glycated hemoglobin tests (N=4,935), and screening for thyroid function (N=4,457), retinopathy (N=1,602), and nephropathy (N=2,369). CONCLUSIONS:We established an administrative cohort of ∼6,000 individuals with childhood-onset T1D with 20+ years of follow-up data that can be used to describe the association between clinical practice measures and clinical outcomes.