LAS VEGAS – Insulin pump therapy may be cost saving, compared with multiple daily injections for patients with type 2 diabetes who have high insulin dose requirements, according to the results of a small study.
Among high insulin users – those using more than 150 units daily – pump delivery saved more than $12,000 over 4 years because basal rates dropped dramatically owing to better insulin absorption, said certified diabetes educator Phyllis Wolff-McDonagh, DNP, at the annual meeting of the American Association of Diabetes Educators.
Although insulin pump therapy has been well studied and is widely used among patients with type 1 diabetes, evidence backing its use in type 2 diabetes is limited. However, in the few studies that have been done, insulin pumps have been found at least as effective as multiple daily injections at improving hemoglobin A1c levels, and in some cases they did a better job. None of those studies looked at cost.
In this retrospective feasibility study, Dr. Wolff-McDonagh and her associates analyzed the medical records of 15 adults aged 40-64 years. All 15 patients had started insulin pump therapy within the previous 7 years after failing to achieve HbA1c levels below 8% despite multiple daily injection (MDI) therapy for at least 1 year (Diabetes Educ. 2010;36:657-65).
At baseline, the mean HbA 1c level was 9.4%. There was a significant 10% decline in HbA 1c level at 3 months, which was maintained at 6 months, but the HbA 1c level was no longer significantly different from baseline at 1 year (9.8%). However, with the removal of a single outlier patient whose HbA 1c had actually increased by 22%, the 1-year 8.2% drop in HbA 1c was significant, compared with baseline, reported Dr. Wolff-McDonagh of the Diabetes and Endocrinology Center of Suffolk, Patchogue, N.Y.
As is often observed in both type 1 and type 2 diabetes patients, the improved glycemic control was associated with a significant increase in body mass index, from 38.6 kg/m2 at baseline to 40.0 kg/m2 at 1 year, with a leveling off at 6 months. This weight gain is believed to result from a reduction in glycosuria with improved glycemic control, she noted.
There was no significant change from baseline in bolus insulin doses at 3, 6, or 12 months, but basal insulin use was significantly lower than baseline at all three time points. The delivery of continual small amounts of basal insulin – as opposed to a single injection of long-acting basal insulin with MDI – appears to reduce insulin resistance and improve absorption, resulting in a substantial decrease in basal insulin use, she noted.
For the cost analysis, patients were divided into three groups according to the level of basal insulin use prior to pump initiation: a low-dose group (less than 100 units/day), a moderate-dose group (100-150 units/day), and a heavy-use group (more than 150 units/day). Cost calculations included both supplies (syringes or pen needles, pump plus pump supplies) and the insulin.
The cost of MDI, assuming four injections per day, totaled $525/year or $2,100 for 4 years, the length of an insulin pump warranty. Costs of pump therapy were a one-time $5,250 charge for the pump, plus $1,500 per year for supplies, totaling $11,250 for 4 years. For the low-dose patients, MDI was less expensive than pump delivery over the 4 years: $9,172 vs. $14,994. For the moderate-use group, the costs were about equal: $22,380 for MDI and $23,002 for pump therapy.
However, for the heavy-use group, MDI was significantly more expensive than pump therapy: $41,100 vs. $28,826. With the potential cost savings from improved glycemic control factored in, insulin pumps could also prove cost savings even for the moderate-use group, Dr. Wolff-McDonagh pointed out.
Moreover, for patients taking extremely large doses of insulin, using U-500 insulin in the pump – currently an off-label use – offers further potential cost savings: A 20-mL vial of U-500 insulin is about $337, and a 10-mL vial of insulin analogue is about $120. Because U-500 insulin is five times as concentrated, the cost is approximately one-quarter that of U-100 insulin per unit, she noted.
The lack of reimbursement for insulin pump use in patients with type 2 diabetes is a major obstacle to its wider use. Medicare uses C-peptide level to determine pump eligibility, a policy that is not evidence based. "Medicare needs to re-look at this, but before that can happen, large randomized controlled studies need to be done to see what happens over long periods of time," Dr. Wolff-McDonagh said.
Dr. Wolff-McDonagh stated that she had no financial disclosures.