The Adherence and Outcomes Benefits of Using a Connected, Reusable Auto-Injector for Self-Injecting Biologics: A Narrative Review

Many biologics are now self-administered by patients at home. A variety of self-injection devices are available, including vials and syringes, prefilled syringes, and spring-driven prefilled pens or auto-injectors. Each has advantages and drawbacks, and different devices suit different patients. For example, some patients have difficulty achieving consistent and successful self-injection due to poor manual dexterity, or experience anxiety at the prospect of self-injection or injection-site pain. These factors can reduce patients' medication adherence and overall experience. Furthermore, while self-injection brings patients many benefits, the proliferation of single-use injection devices has implications for environmental sustainability, including the reliance on single-use plastics, repeated freighting requirements, and need for incineration as hazardous waste. Recently developed, innovative electromechanical auto-injector devices offer technological enhancements over existing devices to overcome some of these issues. Features include customisable injection speeds or durations, consistent rate of injection, electronic injection logs and reminders, and step-by-step, real-time instructions. Indeed, a growing body of evidence points to higher adherence rates among patients using electromechanical devices compared with other devices. Further, with time, the reusability of electromechanical devices may prove to lighten the environmental impact compared with disposable devices, especially as research continues to optimise their sustainability, driven by increased consumer demands for environmental responsibility. This narrative review discusses the differences between prefilled syringes, spring-driven prefilled pens, and electromechanical devices. It also explores how these features may help reduce injection-associated pain and anxiety, improve patient experience, connectivity and adherence, and drive sustainability of biologic drugs in future. Biologics are a type of medicine becoming widespread in the treatment of many diverse diseases. Biologics are injected under the skin and can sometimes be injected by patients themselves at home. Many injection devices are available to help patients with this self-injection, and fall into three broad categories: prefilled syringes, prefilled pens, and electromechanical devices. Each has its own advantages and disadvantages, and different devices suit different patients. For example, some patients have difficulty achieving consistent and successful self-injection because of limited hand movement or become anxious at the prospect of self-injection or injection-site pain. These factors can reduce patients' ability and willingness to take medication as prescribed and may worsen their overall experience. Further, many disposable devices involve single-use plastics and may pose an environmental toll. Reusable electromechanical devices are the newest of the available devices and offer enhanced features over some earlier devices. These include customisable injection speeds or durations, consistent rates of injection, electronic injection logs, reminders, and real-time instructions. Evidence suggests that patients using electromechanical devices may have higher rates of adherence (i.e. more patients take their medication as prescribed) than those using other devices. Additionally, with time and further research, the reusability of electromechanical devices may prove to lighten the environmental impact compared with disposable devices. Here we discuss the differences between prefilled pens, prefilled syringes, and electromechanical devices, and explore the features that may help reduce injection-associated pain and anxiety, improve patient experience, connectivity, and adherence, and drive greater sustainability.