Tight control for older adults offers only modest benefits?…
Vijan and colleagues have provided an insightful summary of the complexity of patient care and the potential risk of simply chasing HbA1c in the management of diabetes. They reviewed the data of the potential benefit of lowering HbA1c at different age groups while also bringing into the equation the burden and potential harm of treatment. With an estimate of a 15% reduction in CV events with a 1% reduction in HbA1c, the authors used quality-adjusted life years (QALY) to determine potential benefit of aggressive treatment in those with a HbA1c <9%.
The graphic shows that the longer blood sugar is kept under control, the more benefit the patient obtains. The older a patient gets, the more burden of treatment may offset the gains.
The purpose of the study was to examine how treatment burden affects the benefits of intensive vs moderate glycemic control in patients with type 2 diabetes.
The researchers estimated the effects of hemoglobin A1c (HbA1c) reduction on diabetes outcomes and overall quality-adjusted life years (QALYs) using a Markov simulation model. Model probabilities were based on estimates from randomized trials and observational studies. Simulated patients were based on adult patients with type 2 diabetes drawn from the National Health and Nutrition Examination Study.
The treatments consisted of glucose lowering with oral agents or insulin in type 2 diabetes. Main outcomes were QALYs and reduction in risk of microvascular and cardiovascular diabetes complications.
Assuming a low treatment burden (0.001, or 0.4 lost days per year), treatment that lowered HbA1c level by 1 percentage point provided benefits ranging from 0.77 to 0.91 QALYs for simulated patients who received a diagnosis at age 45 years to 0.08 to 0.10 QALYs for those who received a diagnosis at age 75 years. An increase in treatment burden (0.01, or 3.7 days lost per year) resulted in HbA1c level lowering being associated with more harm than benefit in those aged 75 years. Across all ages, patients who viewed treatment as more burdensome (0.025-0.05 disutility) experienced a net loss in QALYs from treatments to lower HbA1c level.
In conclusion, improving glycemic control can provide substantial benefits, especially for younger patients; however, for most patients older than 50 years with an HbA1c level less than 9% receiving metformin therapy, additional glycemic treatment usually offers at most modest benefits. Furthermore, the magnitude of benefit is sensitive to patients’ views of the treatment burden, and even small treatment adverse effects result in net harm in older patients. The current approach of broadly advocating intensive glycemic control should be reconsidered; instead, treating patients with HbA1c levels less than 9% should be individualized on the basis of estimates of benefit weighed against the patient’s views of the burdens of treatment.
- The younger the adult patient, the more benefit obtained from aggressive control
- With an increase in treatment burden, HbA1c level lowering was associated with more harm than benefit in those aged 75 years.
- Although improving glycemic control can provide substantial benefits for younger patients, only modest benefits may be seen in patients older than 50 years with an HbA1c less than 9%.
JAMA Intern Med 2014 Jun 30;[EPub Ahead of Print], S Vijan, JB Sussman, JS Yudkin, RA Hayward