Lithium point-of-care testing to improve adherence to monitoring guidelines and quality of maintenance therapy for bipolar disorder: a randomised feasibility trial.

Lithium is the first-line treatment for bipolar disorder. Due to its narrow therapeutic window and risk of toxicity, people taking lithium require regular blood testing to monitor lithium serum levels. However, studies within the National Health Service (NHS) have reported that only half of lithium-treated patients receive adequate lithium serum monitoring. The aim of this project is to test feasibility and acceptability of a point-of-care lithium blood testing programme in patients with bipolar disorder on lithium maintenance treatment. The primary objective is to establish whether testing the effectiveness of point-of-care testing is feasible, by assessing recruitment, attrition, adherence to monitoring guidelines compared to participants randomised to testing as usual, and to test whether the programme is acceptable to patients and healthcare professionals. Further objectives are to examine changes in health-related quality of life, use of healthcare services, work absence, and depressive and manic symptoms, to inform on the design of a larger, multi-site randomised controlled trial (RCT). This feasibility RCT will take place between 1st April 2025 and 31st March 2027, lasting 24 months, across two sites in the UK; South London and Maudsley NHS Foundation Trust (SLaM) and Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust (CNTW). Eighty participants with bipolar disorder who are already taking lithium will be recruited and randomised to point-of-care monitoring (n = 40) or monitoring as usual (n = 40). Participants aged 18 and above with a diagnosis of bipolar disorder, who have initiated lithium in the past 6 months will be recruited from secondary care services and consent for contact patient registries. Patients will be followed up over 26 months and attend three research visits within this time (screening and baseline visit, week 13 and week 26). Randomisation will take place on the same day as baseline. The proportion of patients meeting National Institute for Health and Care Excellence (NICE) guidelines for frequency of tests and test readings within the therapeutic range will be summarised between arms over 26 weeks. Recruitment and attrition rates will be summarised with descriptive statistics and evaluated on pre-defined thresholds. Acceptability data from patient and healthcare professional questionnaires will be assessed using descriptive statistics and qualitative analysis. Mean differences between arms in health-related quality of life, health service use costs, and manic and depressive symptoms will be calculated to estimate effect sizes for a substantive RCT. The results of the study will be published in open access peer-reviewed journals and presented at national and international conferences. King s College London and NHS press offices will also publicise the findings, and results will be presented within clinical services. We will also work with our lived experience panel and the charity Bipolar UK to ensure that findings are effectively disseminated to people with bipolar disorder and their families. Depending on the results of the study, an application will be made to conduct a multi-site RCT to examine clinical and cost-effectiveness of point-of-care testing compared to monitoring as usual across multiple NHS services within the UK.