ELEMENT | DESCRIPTION |
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Overview | In the study by Cameron et al, the authors sought to clarify the costs and benefits of blood glucose self-monitoring in patients with type 2 diabetes who were not using insulin.9 A meta-analysis of RCTs comparing self-monitoring with no self-monitoring showed that HbA1c was 0.25% (95% CI 0.36% to 0.15%) lower in patients who were randomized to blood glucose self-monitoring.12 Although the difference was statistically significant, it was uncertain whether this would translate into clinically significant health benefits. Moreover, the cost associated with blood glucose test strips was estimated to be more than $370 million in Canada in 2006, more than 50% of which was for patients not taking insulin. In order to better inform decisions regarding prescribing and reimbursement of blood glucose test strips, the authors performed a cost-utility analysis of self-monitoring of blood glucose compared with no self-monitoring for patients with type 2 diabetes who were not using insulin9 |
Target population | Patients with type 2 diabetes who did not use insulin. Baseline characteristics of the population were similar to those of patients enrolled in clinical trials, which excluded patients with impending diabetes-related complications or a history of serious disease. The authors performed subgroup analyses for patients receiving only lifestyle interventions and for patients receiving pharmacotherapy with or without lifestyle interventions |
Comparators | Self-monitoring of blood glucose (in the RCTs this was done an average of 1.29 times per day) compared with a strategy of no self-monitoring |
Perspective | The publicly funded health care system |
Time horizon | Lifetime of patients |
Outcomes | The primary outcome was QALYs. The authors began with an estimate of the effect of self-monitoring on HbA1c and, based on this effect, they used modeling techniques to derive the difference in both diabetes-related end points and life expectancy that would be expected given the achieved difference in HbA1c. The life-years of hypothetical patients were then weighted by the utility associated with the various health states |
Data inputs | Effectiveness data: the clinical effectiveness of self-monitoring of blood glucose compared with no self-monitoring in reducing HbA1c was taken from a systematic review and meta-analysis of 7 RCTs Supplementary clinical data: the effect that the difference in HbA1c had on the occurrence of diabetes-related complications was determined using a mathematical model based on observational clinical data from the UKPDS trial Cost data: the cost of the intervention was determined using data from a Canadian provincial drug program, while resource use and costs for the final health outcomes were determined using administrative data |
Discounting | Health effects and costs were discounted at an annual rate of 5%10 |
Results | Cameron et al detailed the projected effect of glucose self-monitoring on 7 important diabetes-related complications and provided a breakdown of the costs and benefits of both strategies before combining them into a cost-utility ratio. They found that, compared with no self-monitoring, self-monitoring was associated with a cost per QALY gained of $113 643. In the patient subgroup receiving only lifestyle interventions, the cost-utility ratio was less favourable at $292 144 per QALY |
Sensitivity analysis | The cost-effectiveness of self-monitoring for blood glucose was sensitive to the price of test strips and the frequency of monitoring but remained stable when other assumptions were varied |
Conclusion | Compared with other health care interventions, self-monitoring of blood glucose does not appear to be a cost-effective use of health care resources in patients with type 2 diabetes not using insulin |
HbA1c—glycosylated hemoglobin A1c, QALY—quality-adjusted life-year, RCT—randomized controlled trial, UKPDS—United Kingdom Prospective Diabetes Study.