Coverage of insulin delivery devices and basal insulin analogs by US managed care organizations.

Objective: The perception in the US is that insulin formulations prescribed for type 1 and type 2 diabetes and delivered via insulin pens are more costly to patients than the same or similar products provided in vials, and that basal insulin analogs offered either in pens or vials are likewise more costly to patients than human insulin formulations. This study compares levels of coverage and copays by private and Medicare Part D plans for insulin pens and vials containing basal insulin analogs and for NPH formulations in vials.

Methods: A commercially available formulary database (Access Point, Pinsonault Associates; updated quarterly) was analyzed as of January 2010 for private insurance plans and as of March 2010 for Medicare Part D plans. Analyses were performed for Tier-level coverage and copays per prescription for basal insulin analogs in pens and vials, and NPH in vials.

Results: Basal insulin analogs in pens were covered by >91% of private and Part D plans. NPH coverage was reported by >92% of private plans and 69-95% of Part D plans, depending on brand. Irrespective of delivery mode, copays in the majority of private plans for basal insulin analogs and NPH were in the >$10-35 range. Copays were higher in Part D plans, with the majority of plans and subscribers in a >$35-50 range. Prior authorization was required by <10% of insurance plans for insulin analog pen prescriptions, and <3% of plans for insulin analog or NPH prescriptions in vials.

Limitations: This analysis was descriptive, copay stratification was not based on a statistical model but on copay ranges typically used by the plans, and there were no direct correlations performed on the numbers of subscribers per plan vs copay or Tier level.

Conclusion: These results counter the widely held perception that insurance coverage is less extensive for insulin pens vs vials. Medicare Part D plans often had higher copay requirements than private plans for the same product at the same copay Tier.