The large scale realignment of individual diagnostic and procedural codes demanded close analysis of the impacts to existing indicators of healthcare delivery. Using data reported in 2001 and 2002, the Canadian Institute for Health Information, an independent organization that works with the federal government, tabulated the input. Rigorous statistical analysis was conducted to evaluate the comparability of ICD-9 codes to ICD-10 codes as they pertained to the Canadian version of diagnostic groups, Case Mix Groups (CMGs), which are used in the patient classification system to group together patients with similar characteristics.