Safety and usability evaluation of a web-based insulin self-titration system for patients with type 2 diabetes mellitus

The rising incidence of type 2 diabetes mellitus (T2DM) induces severe challenges for the health care system. Our research group developed a web-based system named PANDIT that provides T2DM patients with insulin dosing advice using state of the art clinical decision support technology. The PANDIT interface resembles a glucose diary and provides advice through pop-up messages. Diabetes nurses (DNs) also have access to the system, allowing them to intervene when needed. The objective of this study was to establish whether T2DM patients can safely use PANDIT at home. To this end, we assessed whether patients experience usability problems with a high risk of compromising patient safety when interacting with the system, and whether PANDIT's insulin dosing advice are clinically safe. The study population consisted of patients with T2DM (aged 18-80) who used a once daily basal insulin as well as DNs from a university hospital. The usability evaluation consisted of think-aloud sessions with four patients and three DNs. Video data, audio data and verbal utterances were analyzed for usability problems encountered during PANDIT interactions. Usability problems were rated by a physician and a usability expert according to their potential impact on patient safety. The usability evaluation was followed by an implementation with a duration of four weeks. This implementation took place at the patients' homes with ten patients to evaluate clinical safety of PANDIT advice. PANDIT advice were systematically compared with DN advice. Deviating advice were evaluated with respect to patient safety by a panel of experienced physicians, which specialized in diabetes care. We detected seventeen unique usability problems, none of which was judged to have a high risk of compromising patient safety. Most usability problems concerned the lay-out of the diary, which did not clearly indicate which data entry fields had to be entered in order to obtain an advice. 27 out of 74 (36.5%) PANDIT advice differed from those provided by DNs. However, only one of these (1.4%) was considered unsafe by the panel. T2DM patients with no prior experience with the web-based self-management system were capable of consulting the system without encountering significant usability problems. Furthermore, the large majority of PANDIT advice were considered clinically safe according to the expert panel. One advice was considered unsafe. This could however easily be corrected by implementing a small modification to the system's knowledge base