Cost-effectiveness of self-monitoring of blood glucose in patients with type 2 diabetes mellitus managed without insulin

Background

The benefits of self-monitoring blood glucose levels are unclear in patients with type 2 diabetes mellitus who do not use insulin, but there are considerable costs. We sought to determine the cost effectiveness of self-monitoring for patients with type 2 diabetes not using insulin.

Methods

We performed an incremental cost-effectiveness analysis of the self-monitoring of blood glucose in adults with type 2 diabetes not taking insulin. We used the United Kingdom Prospective Diabetes Study (UKPDS) model to forecast diabetes-related complications, corresponding quality-adjusted life years and costs. Clinical data were obtained from a systematic review comparing self-monitoring with no self-monitoring. Costs and utility decrements were derived from published sources. We performed sensitivity analyses to examine the robustness of the results.

Results

Based on a clinically modest reduction in hemoglobin A_1C of 0.25% (95% confidence interval 0.15–0.36) estimated from the systematic review, the UKPDS model predicted that self-monitoring performed 7 or more times per week reduced the lifetime incidence of diabetes-related complications compared with no self-monitoring, albeit at a higher cost (incremental cost per quality-adjusted life year $113 643). The results were largely unchanged in the sensitivity analysis, although the incremental cost per quality-adjusted life year fell within widely cited cost-effectiveness thresholds when testing frequency or the price per test strip was substantially reduced from the current levels.

Interpretation

For most patients with type 2 diabetes not using insulin, use of blood glucose test strips for frequent self-monitoring (≥ 7 times per week) is unlikely to represent efficient use of finite health care resources, although periodic testing (e.g., 1 or 2 times per week) may be cost-effective. Reduced test strip price would likely also improve cost-effectiveness.Self-monitoring of blood glucose in patients with diabetes who use insulin may contribute to improved glycemic control and reduced hypoglycemia by allowing for self-adjustments in insulin dose to be made based on meter readings.¹ Self-monitoring may also allow for appropriate changes in diet and physical activity to be made. However, the benefits of self-monitoring of blood glucose for patients not using insulin are less clear. Hypoglycemia is less frequent in this population² and is confined mainly to those taking secretagogues. The degree to which patients can adjust the dose of oral antidiabetes drugs in response to readings is limited.Nevertheless, self-monitoring of blood glucose is routinely recommended for patients who are not using insulin.¹ This results in major investments in this technology by patients and payers.³ In 2006, $250 million was spent on blood glucose test strips in 8 publicly funded drugs plans in Newfoundland and Labrador, Nova Scotia, Quebec, Ontario, Manitoba, Saskatchewan and British Columbia, while over $120 million was spent in privately funded drug plans in Canada.⁴ In some publicly funded drug plans in Canada, blood glucose test strips are among the top 5 classes in terms of total expenditure,⁵ with costs exceeding those for all oral antidiabetes drugs combined.^4,6 It is estimated that more than 50% of the total expenditure on blood glucose test strips is for patients with type 2 diabetes who are not using insulin.³ Costs related to test strips are expected to rise steadily^5,7 because of the increasing prevalence of type 2 diabetes.⁸Decisions about the prescribing and reimbursement of blood glucose test strips require consideration of information about the costs and clinical benefits.^9,10 As part of a larger initiative to determine the optimal use of this technology, we sought to determine the cost-effectiveness of self-monitoring of blood glucose for patients with type 2 diabetes who do not use insulin, based on data from our systematic review¹¹ of the available clinical evidence.