Patient view of treatment burden critical to health gains in T2DM

Although intensive glycemic control has been the standard of care for delaying the onset and slowing the progression of microvascular disease, treatment burden and unwanted effects like weight gain, hypoglycemia, and gastrointestinal side effects do affect patients’ quality of life. Patient preferences and their views of treatment burden need to be considered when making decisions about glycemic treatment, according to a report published online for JAMA Internal Medicine.

Researchers from the Center for Clinical Management Research at Ann Arbor Veterans Affairs Hospital, Ann Arbor, Mich., decided to examine the effect of treatment burden on the benefits of intensive and moderate glycemic control in patients with type 2 diabetes. Using a Markov simulation model, they estimated the effects of hemoglobin A1c (HbA1c) lowering on diabetes outcome and the patients’ overall quality-adjusted life years (QALYs). They used data from randomized and observational studies. Simulated patients were based on adults with diabetes from the National Health and Nutrition Examination Study.

The interventions for glucose lowering were oral agents or insulin therapy and the main health outcomes were QALYs and reduced risk of microvascular and cardiovascular diabetes complications.

Treatment burdens

In the first treatment scenario, a new middle-aged patient is diagnosed with diabetes with a baseline HbA1c level of 8.5% and is started on metformin to achieve an HbA1c level of 7.0%. The patient’s quality of life is measured on a utility scale of 1 for perfect health and 0 for death. In the case of the middle-aged patient, persistent gastrointestinal adverse effects had a disutility of 0.04 for those who experience the side effect (10% of patients based on clinical reports), which translates into a mean loss of 0.004 or 1.46 days of high-quality of life per year, according to the authors. Minor hypoglycemia, which occurs in about 0.4% of patients each year, resulted in a disutility of 0.01. For this patient, the total mean disutility was 0.00404 or about 1.47 days that are lost of high-quality life per year.

In the second treatment scenario, the same patient 10 years later is prescribed insulin if the HbA1c level reaches 8.5%, which occurred in patients in the UK Prospective Diabetes Study. Daily insulin injections had a disutility of about 0.03, weight gain had a disutility of 0.007 per year, minor hypoglycemia had a disutility of 0.01, and major hypoglycemia had a disutility of 0.03. The total mean disutility was 0.0372 or about 13.6 days lost of high-quality life per year. The authors also identified key variables that were important for sensitivity analyses such as age when first diagnosed, baseline HbA1c level before therapy, and treatment disutility.

“We found substantial benefits to lowering HbA1c level, particularly among younger individuals,” with a gain of 0.906 QALYs for the middle-aged patient lowering HbA1c by 1% from a baseline of 8.5%, the authors noted.

“This benefit is smaller in older individuals, declining to a gain of 0.269 QALYs at age 65 years and 0.104 QALYs at age 75 years,” they wrote.

The patient’s perception of the treatment and the accompanying side effects has a significant impact on the benefits of glucose reduction. Even among a middle-aged patient who was in the first treatment scenario, there was a perceived high treatment burden of 0.05 or 18.2 days lost of high-quality life per year, which is reported by individuals taking insulin.

“Indeed, the model predicts that patients will lose between 0.653 and 0.818 QALYs even when treatments improve glycemic control by 1%. The treatment burden at which reducing HbA1c level by 1 point results in net harm ranges between 0.01 and 0.05, depending on other key factors such as patient age and pretreatment HbA1c level ,” the authors explained in their report.

The authors estimated a negative effect on QALYs when switching to insulin in all age groups. They concluded that patient age, pretreatment HbA1c level, and patient view of treatment burden affect the treatment benefit of glycemic therapies.

“Each glycemic treatment decision should be individualized, mostly on the basis of patients’ view of the burdens of therapy, with age and initial level of glycemic control important but secondary considerations,” they said.