Commentary Explores the Construction of a Clinical Indicator for the Risk of Over-Treatment among Elderly Patients with Diabetes
Microvascular complications of diabetes have been attributed to poor glycemic control, which led to an increasing emphasis on tight glucose control. However, the publication of three major trials, including the VA Diabetes Trial (VADT), prompted greater attention to the potential harms of overly tight control, especially in the elderly and those with cardiovascular disease. In response, the National Committee for Quality Assurance Healthcare Effectiveness Data and Information Set (HEDIS) modified its glycohemoglobin goal to less than 7% for individuals younger than 65 years without cardiovascular disease or end-stage complications and diabetes — and established a new goal of less than 8% for individuals 65 to 74 years of age. Another important factor is the increasing recognition that although glycohemoglobin tests are standardized, measurements may vary as much as 0.5% due to measurement error. The high frequency of risk factors for hypoglycemia and its adverse impact, the marginal benefits of tight control in individuals with short life expectancy, and potential for inaccurate measures suggest a need for a quality measure to reduce over-treatment, particularly among elderly patients. This Commentary discusses these issues and explores the construction of a clinical indicator for the risk of over-treatment.
Sponsored by the Association for Healthcare Research and Quality, a conference on diabetes performance measures resulted in several recommendations to improve measures; for example, performance measures should:
- Be constructed so that the credit for achieving the measure is commensurate with the likelihood of benefit to the patient;
- Be constructed so that the eligible population reflects the population(s) that will receive the benefit; and
- Motivate improvements in quality, while minimizing problems with patient safety and unintended consequences.
With these principles in mind, the authors propose a glycohemoglobin concentration of less than 7.0% as a threshold measure of potential over-treatment of individuals older than 65 years who are at high risk for hypoglycemia. They also suggest patients aged 75 years and older be evaluated by this proposed measure because the risk of serious adverse events is greater with increased age. They further suggest that a measure for over-treatment would be most appropriate as an indicator to prompt clinician re-evaluation of the appropriateness of glycemic treatment; however, it would not be appropriate as an accountability measure without further refinement, including incorporating glomerular filtration rates and life expectancy, among other variables.
This study was partly funded by VA/HSR&D Quality Enhancement Research Initiative (QUERI). Drs. Pogach (Clinical Coordinator) and Aron are both part of Diabetes-QUERI.
Pogach L and Aron D. The Other Side of Quality Improvement in Diabetes for Seniors. A Proposal for an Over-Treatment Glycemic Measure. Archives of Internal Medicine, Commentary September 10, 2012; Epub ahead of print.