1
|
Banerjee S, Farina N, Henderson C, High J, Stirling S, Shepstone L, Fountain J, Ballard C, Bentham P, Burns A, Fox C, Francis P, Howard R, Knapp M, Leroi I, Livingston G, Nilforooshan R, Nurock S, O'Brien J, Price A, Thomas AJ, Swart AM, Telling T, Tabet N. A pragmatic, multicentre, double-blind, placebo-controlled randomised trial to assess the safety, clinical and cost-effectiveness of mirtazapine and carbamazepine in people with Alzheimer's disease and agitated behaviours: the HTA-SYMBAD trial. Health Technol Assess 2023; 27:1-108. [PMID: 37929672 PMCID: PMC10641860 DOI: 10.3310/vpdt7105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023] Open
Abstract
Background Agitation is common and impacts negatively on people with dementia and carers. Non-drug patient-centred care is first-line treatment, but we need other treatment when this fails. Current evidence is sparse on safer and effective alternatives to antipsychotics. Objectives To assess clinical and cost-effectiveness and safety of mirtazapine and carbamazepine in treating agitation in dementia. Design Pragmatic, phase III, multicentre, double-blind, superiority, randomised, placebo-controlled trial of the clinical effectiveness of mirtazapine over 12 weeks (carbamazepine arm discontinued). Setting Twenty-six UK secondary care centres. Participants Eligibility: probable or possible Alzheimer's disease, agitation unresponsive to non-drug treatment, Cohen-Mansfield Agitation Inventory score ≥ 45. Interventions Mirtazapine (target 45 mg), carbamazepine (target 300 mg) and placebo. Outcome measures Primary: Cohen-Mansfield Agitation Inventory score 12 weeks post randomisation. Main economic outcome evaluation: incremental cost per six-point difference in Cohen-Mansfield Agitation Inventory score at 12 weeks, from health and social care system perspective. Data from participants and informants at baseline, 6 and 12 weeks. Long-term follow-up Cohen-Mansfield Agitation Inventory data collected by telephone from informants at 6 and 12 months. Randomisation and blinding Participants allocated 1 : 1 : 1 ratio (to discontinuation of the carbamazepine arm, 1 : 1 thereafter) to receive placebo or carbamazepine or mirtazapine, with treatment as usual. Random allocation was block stratified by centre and residence type with random block lengths of three or six (after discontinuation of carbamazepine, two or four). Double-blind, with drug and placebo identically encapsulated. Referring clinicians, participants, trial management team and research workers who did assessments were masked to group allocation. Results Two hundred and forty-four participants recruited and randomised (102 mirtazapine, 102 placebo, 40 carbamazepine). The carbamazepine arm was discontinued due to slow overall recruitment; carbamazepine/placebo analyses are therefore statistically underpowered and not detailed in the abstract. Mean difference placebo-mirtazapine (-1.74, 95% confidence interval -7.17 to 3.69; p = 0.53). Harms: The number of controls with adverse events (65/102, 64%) was similar to the mirtazapine group (67/102, 66%). However, there were more deaths in the mirtazapine group (n = 7) by week 16 than in the control group (n = 1). Post hoc analysis suggests this was of marginal statistical significance (p = 0.065); this difference did not persist at 6- and 12-month assessments. At 12 weeks, the costs of unpaid care by the dyadic carer were significantly higher in the mirtazapine than placebo group [difference: £1120 (95% confidence interval £56 to £2184)]. In the cost-effectiveness analyses, mean raw and adjusted outcome scores and costs of the complete cases samples showed no differences between groups. Limitations Our study has four important potential limitations: (1) we dropped the proposed carbamazepine group; (2) the trial was not powered to investigate a mortality difference between the groups; (3) recruitment beyond February 2020, was constrained by the COVID-19 pandemic; and (4) generalisability is limited by recruitment of participants from old-age psychiatry services and care homes. Conclusions The data suggest mirtazapine is not clinically or cost-effective (compared to placebo) for agitation in dementia. There is little reason to recommend mirtazapine for people with dementia with agitation. Future work Effective and cost-effective management strategies for agitation in dementia are needed where non-pharmacological approaches are unsuccessful. Study registration This trial is registered as ISRCTN17411897/NCT03031184. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 23. See the NIHR Journals Library website for further project information.
Collapse
Affiliation(s)
- Sube Banerjee
- Faculty of Health, University of Plymouth, Plymouth, UK
| | - Nicolas Farina
- Faculty of Health, University of Plymouth, Plymouth, UK
- Centre for Dementia Studies, Brighton and Sussex Medical School, University of Sussex, Brighton and Hove, UK
| | - Catherine Henderson
- Care Policy and Evaluation Centre, London School of Economics and Political Science, London, UK
| | - Juliet High
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Susan Stirling
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Lee Shepstone
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Julia Fountain
- Coordinator for Service User and Carer Involvement in Research, Sussex Partnership NHS Foundation Trust, Brighton and Hove, UK
| | - Clive Ballard
- College of Medicine and Health, University of Exeter, Exeter, UK
| | - Peter Bentham
- Birmingham and Solihull Mental Health Foundation NHS Trust, Birmingham, UK
| | - Alistair Burns
- Department of Psychiatry, University of Manchester, Manchester, UK
| | - Chris Fox
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Paul Francis
- College of Medicine and Health, University of Exeter, Exeter, UK
| | - Robert Howard
- Division of Psychiatry, University College London, London, UK
| | - Martin Knapp
- Care Policy and Evaluation Centre, London School of Economics and Political Science, London, UK
| | - Iracema Leroi
- Department of Psychiatry, Global Brain Health Institute, Trinity College Dublin, Dublin, Ireland
| | - Gill Livingston
- Division of Psychiatry, University College London, London, UK
| | - Ramin Nilforooshan
- Research and Development, Surrey and Borders Partnership NHS Foundation Trust, Leatherhead, UK
| | - Shirley Nurock
- Former Carer, Alzheimer's Society Research Network, London, UK
| | - John O'Brien
- Department of Psychiatry, University of Cambridge School of Medicine, Cambridge, UK
| | - Annabel Price
- Cambridgeshire and Peterborough Foundation Trust, Cambridge, UK
| | - Alan J Thomas
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Ann Marie Swart
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, UK
| | - Tanya Telling
- Joint Clinical Research Office, University of Sussex, Brighton, UK
| | - Naji Tabet
- Centre for Dementia Studies, Brighton and Sussex Medical School, University of Sussex, Brighton and Hove, UK
| |
Collapse
|