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.