Comorbidity and its relationship with health service use and cost in community-living older adults with diabetes: A population-based study in Ontario, Canada.

Aims: This study describes the comorbid conditions in Canadian, community-dwelling older adults with diabetes and the association between the number of comorbidities and health service use and costs.

Methods: This retrospective cohort study used multiple linked administrative data to determine 5-year health service utilization in a population-based cohort of community-living individuals aged 66 and over with a diabetes diagnosis as of April 1, 2008 (baseline). Utilization included physician visits, emergency department visits, hospitalizations, and home care services.

Results: There were 376,421 cohort members at baseline, almost all (95%) of which had at least one comorbidity and half (46%) had 3 or more. The most common comorbidities were hypertension (83%) and arthritis (61%). Service use and associated costs consistently increased as the number of comorbidities increased across all services and follow-up years. Conditions generally regarded as nondiabetes-related were the main driver of service use. Over time, use of most services declined for people with the highest level of comorbidity (3+). Hospitalizations and emergency department visits represented the largest share of costs for those with the highest level of comorbidity (3+), whereas physician visits were the main costs for those with fewer comorbidities.

Conclusions: Comorbidities in community-living older adults with diabetes are common and associated with a high level of health service use and costs. Accordingly, it is important to use a multiple chronic conditions (not single-disease) framework to develop coordinated, comprehensive and patient-centred programs for older adults with diabetes so that all their needs are incorporated into care planning.