Usability Testing of Insulin Pens and Cartridges

Healthcare Human Factors


Insulin pens and cartridges provide an alternative method to administer insulin to diabetes patients. In comparison to traditional vials and syringes, insulin pens can simplify the administration process and increase dose accuracy through the precise display and selection of dosing units. However, introducing a new process into an already existing workflow may bring new risks and challenges. That was why when Toronto Western Hospital decided to pilot insulin pens for administration to patients by nurses, they looked to Healthcare Human Factors.

To identify safety risks and usability issues with the new workflow and insulin administration process, Healthcare Human Factors conducted usability testing with each of the proposed insulin pen and cartridge systems. The candidate systems were:

  • Humapen® Luxura™
  • NovoPen® 4
  • Humalog® Kwikpen™
  • Lantus® SoloSTAR®

A total of 11 nurses participated in the evaluation. They were asked to prepare and inject the pens into patient mannequins, following their normal workflow including interactions with the electronic medical record. A number of usability issues were identified, some of which introduced safety hazards such as medication mix-ups, dosing errors, and contamination.


Usability testing revealed that implementing an insulin pen and cartridge system in place of the needle and vial system was not without associated risks that could impact patient safety. The team recommended strategies to mitigate these risks, which helped subsequent planning and decision-making by the hospital.