Improving the diagnosis and management of Lewy body dementia: the DIAMOND-Lewy research programme including pilot cluster RCT

Abstract

Background Lewy body dementia (LBD), comprising both dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD), is the second commonest cause of neurodegenerative dementia. Existing evidence suggests it is under-diagnosed and without a consistent approach to management. Objectives To improve the diagnosis and management of LBD by: a) understanding current diagnostic practice for DLB and PDD; b) identifying barriers and facilitators to diagnosis and management; c) developing evidence-based assessment toolkits to improve diagnosis of DLB and PDD; d) producing a management toolkit to facilitate management; e) undertaking a pilot cluster randomised clinical trial. Design Work package 1 (WP1) assessed clinical diagnostic rates from casenotes for DLB and PDD before and after (WP1R) introduction of an assessment toolkit. In WP2, we developed a management toolkit for LBD. In WP3 we developed assessment toolkits for DLB and PDD and piloted these and the management toolkit in a clinical service. In WP4 we undertook a pilot study of 23 services in nine NHS trusts who were cluster randomised to receiving and using the management toolkit or standard care. WP5 comprised a series of qualitative studies examining barriers and facilitators to diagnosis and management. Setting Secondary care memory assessment and movement disorder services in England. Interventions Assessment toolkits for LBD consisted of questions for diagnostic symptoms, management toolkits comprised 161 guidance statements grouped under 5 symptom domains. Review methods The systematic reviews of pharmacological and non-pharmacological management were based on published literature, with meta-analysis when possible, following search of several electronic 10 databases and the grey literature using terms related to Lewy Body Dementia, without restriction on time or language. Participants Participants aged over 50 diagnosed with DLB or PDD and, for WP1 and WP1R, non-DLB and nonPDD controls. The qualitative studies included people with LBD, carers and professionals. Main outcome measures For WP1 and 1R, diagnostic rates for DLB and PDD as a proportion of all dementia or PD. For WP2 and WP3 the production of diagnostic and management toolkits. For WP4 feasibility of undertaking a cluster randomised trial of the toolkits, measured by number of participants recruited and use of the toolkits, assessed qualitatively. Results WP1: 4.6% of dementia cases in secondary care received a DLB diagnosis, with significant differences in diagnostic rates between services and 9.7% of those with Parkinson’s disease had a diagnosis of PDD. There was evidence of delays in diagnosis for both DLB and PDD compared to controls, and costs of DLB and PDD were also greater than those for matched controls (p <0.01 for both). WP2: We produced 252 statements regarding LBD management and, following a Delphi process, 161 statements were included in a management toolkit. WP3: Piloting indicated that separate assessment toolkits for use in memory clinic and movement disorder services were preferred, but a single toolkit for LBD management was suitable. WP4: We were able to recruit LBD subjects to target, and recruited 131 patients within 6 months (target 120), of whom over 80% were retained in the study at 6 months. WP5: Barriers to diagnosis and management of LBD were complex. Managing LBD often requires input from a range of specialties, and therefore care pathways may be fragmented. Positive attitudes to diagnosing LBD, working with a team with expertise in LBD and opportunities for cross-specialty 11 discussion of patients with complex needs facilitated diagnosis and management. The toolkits were generally well received, particularly the management toolkit. Implementation, however, varied reflecting differences in attitudes, skills, time and local leadership. WP1R: Following introduction of the assessment toolkit we found that 9.7% of dementia cases had DLB (a significant increase from baseline, p=0.0019) but PDD rates were similar (8.2%) to baseline. Limitations We only included two geographical regions and evidence informing the management toolkit was limited. WP4 was a pilot study, and therefore we did not set out to assess the extent to which use of the management toolkit altered outcomes at the individual patient level. We noted implementation of the toolkits was variable. The increase in diagnostic rates in DLB following introduction of the assessment toolkits cannot be necessarily be causally attributed to them. Conclusions DLB and PDD were diagnosed in secondary care NHS services with a lower frequency (around half) than that expected from known prevalence rates. The introduction of assessment toolkits for DLB and PDD was associated with increased diagnostic rates of DLB but not PDD. Qualitative studies indicated inherent complexities of the disease itself, requiring input from different specialties with the potential for fragmented services, a workforce with variable training and confidence in LBD and negative attitudes towards diagnosis. The cluster randomised pilot trial demonstrated that patients could be successfully recruited and provided preliminary evidence that the toolkits could be implemented in clinical services. Future Work The evidence base informing the management of LBD is limited, especially for non-pharmacological interventions. More well designed randomised controlled trials for both cognitive and non-cognitive symptoms are needed.