Feasibility of eLi12 in a Clinical Setting

Hypothesis The main hypotheses are that 1) the majority (>80%) of patients will register the time since the last lithium dose, 2) there will be a difference between eLi12 and Se-Li among participants who got the lithium blood test at a different time point than 12 hours after the last dose, 3) eLi12 will show less variation compared to the measured lithium concentration, 4) patients will be satisfied with a solution that gives more flexibility regarding blood test timing and will have slightly fewer self-reported symptoms and better quality of life, and 5) clinicians will be satisfied with the eLi12 solution.

Study design Quality assurance study testing the feasibility of eLi12. Patients Patients with a bipolar disorder diagnosis (ICD-10: F30-31) treated with lithium (ATC-code: N05AN01) aged ≥18 years and followed at the bipolar disorder outpatient clinic at AUHP, the outpatient clinic for affective disorders at Randers Psychiatric Hospital, or the outpatient clinic for affective disorders at Gødstrup Psychiatric Hospital.

Procedures The lithium treatment and all blood tests are based on clinical indication prescribed by a clinician independent of the present study with the time for the blood test being booked by the patient (i.e., all independent of the present study protocol representing real-world clinical practice). eLi12 is a new method to estimate the 12-hour Se-Li level when the lithium blood test is not taken 12 hours after the most recent lithium dose. Implementation of eLi12 requires that lithium-treated patients register the time for the most recent lithium intake (i.e., the time when they took their last lithium dose the evening before the blood test) at the time of their lithium blood test. Using the already available data on 1) the Se-Li concentration measured at 2) the time-point of the blood test, the patient-reported time since the last lithium dose can then be used to calculate the eLi12 value. Participants in the present study will be randomized to have their eLi12 value presented in the electronic patient journal MidtEPJ. This means that the measured Se-Li will always be presented (i.e., standard clinical practice will continue as usual), and for 50% of participants, the eLi12 value will also be presented. Hence, during participation in this study, patients will be randomized to either have eLi12 shown together with their usual Se-Li measurement or to only have the Se-Li measurement presented (i.e., treatment-as-usual without the eLi12 estimation). This means that all participants will follow treatment-as-usual with 50% receiving additional information via eLi12. The present study will investigate the feasibility of eLi12 implementation and acquire new data about eLi12, but not acquire new knowledge about lithium as a drug.

Follow-up The study will be conducted from Q4 2025 until December 31, 2027. Individual participation will occur from the date of inclusion until the end of the study. The proposed study period is deemed necessary in order to ensure sufficient time for recruitment and to ensure several blood tests from the same individual to allow for testing the individual variation in Se-Li and eLi12. Patients will be treated and followed according to normal clinical treatment guidelines at the clinic. It will always be up to the attending clinician to evaluate whether a new dose (i.e., increase or decrease of the present lithium dose) is necessary and relevant.

Endpoints The study will evaluate three co-primary outcomes: 1) The percentage of patients registering the time since the last lithium dose, 2) the difference between eLi12 and Se-Li, and 3) for those periods of time where participants have no change in their lithium dose, the variation in eLi12 compared to the actual measured lithium concentrations at ≤10 hours or ≥14 hours from the last dose.