Comparison of Premixed Insulin Analogs and Long-Acting Insulin Analogs

San Diego—An analysis of a diabetes simulation model from a US healthcare payer perspective found that patients with type 2 diabetes taking premixed insulin analogs were likely to have increased life expectancy and quality-adjusted life expectancy compared with those taking long-acting insulin analogs (LAIAs). The authors indicated that premixed insulin analogs were associated with higher lifetime and direct medical costs; the incremental cost-effectiveness ratios per quality-adjusted life-year were $28,580 in the premixed insulin analog group compared with $23,150 in the LAIA group. Results were presented at the ADA meeting in a president’s poster session. The poster was titled Estimating the Long-Term Cost-Effectiveness of Premixed Insulin Analog versus Long-Acting Insulin Analog in the United States. An earlier meta-analysis from the Agency for Healthcare Research and Quality concluded that premixed insulin analogs provided more glycemic control than LAIAs. In this trial, the authors were interested in comparing the cost-effectiveness of the drugs because of the substantial cost of insulin, which is approximately $3.7 billion per year, according to a 2007 ADA report cited by the authors. The drugs used were insulin lispro mix 75/25 (75% insulin lispro protamine suspension, 25% insulin lispro), insulin lispro mix 50/50 (50% insulin lispro protamine suspension, 50% insulin lispro), and an LAIA regimen. The model was validated and included simulations of mortality and incidence of diabetes-related complications. The authors assumed patients took an average of 40 insulin units per day. They obtained insulin costs and direct medical costs from published sources and diabetes complication costs from a 2008 study. In addition, they derived baseline cohort characteristics from published sources. The mean age was 62.8 years, patients had diabetes for a mean of 12.0 years, the mean glycated hemoglobin was 8.6%, and the population included 57.5% males. The mean life expectancy was 7.82 years in the LAIA group, 7.89 in the insulin lispro mix 75/25 group, and 7.91 years in the insulin pro mix 50/50 group. Meanwhile, the mean quality-adjusted life expectancy was 4.93 years in the LAIA group, 5.00 in the insulin pro mix 75/25 group, and 5.01 years in the insulin pro mix 50/50 group. Direct costs associated with the groups were $40,128 (LAIA), $41,852 (insulin pro mix 75/25), and $41,848 (insulin pro mix 50/50). The authors also utilized incremental cost-effectiveness scatter plots and acceptability curves. They found that at a willingness to pay of $50,000 per quality-adjusted life-year gained, there was a 58.8% probability that insulin lispro mix 75/25 would be more cost-effective compared with LAIA and a 64.5% probability that insulin pro mix 50/50 would be more cost-effective compared with LAIA. The authors mentioned limitations to the study, including that they did not include hypoglycemia incidence in the base-case analysis because the treatment effects in the published article they used aggregated all premixed insulin analogs instead of recording them separately. They also performed a meta-analysis of short-term clinical trials to make long-term predictions, which could lead to uncertainty. However, the authors said using a validated and published model is among the best and most accurate ways to project long-term cost-effectiveness. This study was sponsored by Eli Lilly and Co.