Potential diabetes overtreatment and risk of adverse events among older adults in Ontario: a population-based study



More than 25% of older adults (age ≥75 years) have diabetes and may be at risk of adverse events related to treatment. The aim of this study was to assess the prevalence of intensive glycaemic control in this group, potential overtreatment among older adults and the impact of overtreatment on the risk of serious events.


We conducted a retrospective, population-based cohort study of community-dwelling older adults in Ontario using administrative data. Participants were ≥75 years of age with diagnosed diabetes treated with at least one anti-hyperglycaemic agent between 2014 and 2015. Individuals were categorised as having intensive or conservative glycaemic control (HbA1c <53 mmol/mol [<7%] or 54–69 mmol/mol [7.1–8.5%], respectively), and as undergoing treatment with high-risk (i.e. insulin, sulfonylureas) or low-risk (other) agents. We measured the composite risk of emergency department visits, hospitalisations, or death within 30 days of reaching intensive glycaemic control with high-risk agents.


Among 108,620 older adults with diagnosed diabetes in Ontario, the mean (± SD) age was 80.6 (±4.5) years, 49.7% were female, and mean (± SD) diabetes duration was 13.7 (±6.3) years. Overall, 61% of individuals were treated to intensive glycaemic control and 21.6% were treated to intensive control using high-risk agents. Using inverse probability treatment weighting with propensity scores, intensive control with high-risk agents was associated with nearly 50% increased risk of the composite outcome compared with conservative glycaemic control with low-risk agents (RR 1.49, 95% CI 1.08, 2.05).


Our findings underscore the need to re-evaluate glycaemic targets in older adults and to reconsider the use of anti-hyperglycaemic medications that may lead to hypoglycaemia, especially in setting of intensive glycaemic control.

Graphical abstract

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Fig. 1

Data availability

The dataset from this study is held securely in coded form at ICES. While data sharing agreements prohibit ICES from making the dataset publicly available, access may be granted to those who meet pre-specified criteria for confidential access, available at www.ices.on.ca/DAS. The full dataset creation plan and underlying analytic code are available from the authors upon request, understanding that the computer programs may rely upon coding templates or macros that are unique to ICES and are therefore either inaccessible or may require modification.



Emergency department


Inverse probability of treatment weighting


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Parts of this material are based on data and/or information compiled and provided by the Canadian Institute for Health Information (CIHI). However, the analyses, conclusions, opinions and statements expressed in the material are those of the authors, and not necessarily those of CIHI. In addition, we thank IMS Brogan Inc. for use of their Drug Information Database.

The authors wish to acknowledge the assistance of Vaidehi Misra (Women’s College Research Institute, Toronto, ON, Canada) for her assistance with editing and formatting the manuscript.

Authors’ relationships and activities

The authors declare that there are no relationships or activities that might bias, or be perceived to bias, their work.


This study was supported by a grant from the Canadian Institutes of Health Research (CIHR) (1018890). LLL is supported by a Diabetes Investigator Award from Diabetes Canada. PCA is supported by a Mid-Career Investigator Award from the Heart and Stroke Foundation. PAR holds the RTO/ERO Chair in Geriatric Medicine from the University of Toronto. This study was supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). ICES is an independent, non-profit research institute, the legal status of which under Ontario’s health information privacy law allows it to collect and analyse healthcare and demographic data, without consent, for health system evaluation and improvement. The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred.

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ICL conceived the objective of the study. ICL and LLL wrote and edited the manuscript. YN analysed the data. ICL, MAC, PCA, SEB, PAR and LLL contributed to the study design and interpretation of the data, and reviewed/edited the manuscript. AZ, FL and CY contributed to the interpretation of the data and reviewed/edited the manuscript. All authors provided final approval of the manuscript version published. ICL is the guarantor and accepts full responsibility for the work and/or the conduct of the study, had access to the data and controlled the decision to publish.

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Correspondence to Iliana C. Lega.

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Lega, I.C., Campitelli, M.A., Austin, P.C. et al. Potential diabetes overtreatment and risk of adverse events among older adults in Ontario: a population-based study. Diabetologia (2021). https://doi.org/10.1007/s00125-020-05370-7

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  • Diabetes overtreatment
  • Healthcare delivery
  • Hypoglycaemia
  • Insulin secretagogues
  • Insulin therapy
  • Intensive glycaemic control
  • Older adults