Evaluating quality of overall care among older adults with diabetes with comorbidities in Ontario, Canada: a retrospective cohort study

OBJECTIVES: This study aimed to: (1) explore whether the quality of overall care for older people with diabetes is differentially affected by types and number of comorbid conditions and (2) examine the association between process of care measures and the likelihood of all-cause hospitalisations. DESIGN: A population-based, retrospective cohort study. SETTING: The province of Ontario, Canada. PARTICIPANTS: We identified 673 197 Ontarians aged 65 years and older who had diabetes comorbid with hypertension, chronic ischaemic heart disease, osteoarthritis or depression on 1 April 2010. MAIN OUTCOME MEASURES: The study outcome was the likelihood of having at least one hospital admission in each year, during the study period, from 1 April 2010 to 3 March 2014. Process of care measures specific to older adults with diabetes and these comorbidities, developed by means of a Delphi panel, were used to assess the quality of care. A generalised estimating equations approach was used to examine associations between the process of care measures and the likelihood of hospitalisations. RESULTS: The study findings suggest that patients are at risk of suboptimal care with each additional comorbid condition, while the incidence of hospitalisations and number of prescribed drugs markedly increased in patients with 2 versus 1 selected comorbid condition, especially in those with discordant comorbidities. The median continuity of care score was higher among patients with diabetes-concordant conditions compared with those with diabetes-discordant conditions, and it declined with additional comorbid conditions in both groups. Greater continuity of care was associated with lower hospital utilisation for older diabetes patients with both concordant and discordant conditions. CONCLUSIONS: There is a need for focusing on improving continuity of care and prioritising treatment in older adults with diabetes with any multiple conditions but especially in those with diabetes-discordant conditions (eg, depression).