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INTRODUCTION: In the Investigating the Impact of Alzheimers Disease Diagnostics in British Columbia (IMPACT-AD BC) study, we aimed to understand how Alzheimers disease (AD) cerebrospinal fluid (CSF) biomarker testing-used in medical care-impacted medical decision-making (medical utility), personal decision-making (personal utility), and health system economics. METHODS: The study was designed as an observational, longitudinal cohort study. A total of 149 patients were enrolled between February 2019 and July 2021. Patients referred to memory clinics were approached to participate if their dementia specialist ordered AD CSF biomarker testing as part of their routine medical care, and the clinical scenario met the appropriate use criteria for lumbar puncture and AD CSF biomarker testing. For the medical utility pillar, detailed clinical management plans were collected via physician questionnaires pre- and post-biomarker disclosure. RESULTS: Patients with completed management questionnaires (n = 142) had a median age of 64 (interquartile range: 59-69) years, 48% were female, and 60% had CSF biomarker profiles on the AD continuum. Clinical management changed in 89.4% of cases. AD biomarker testing was associated with decreased need for other diagnostic procedures, including brain imaging (-52.0%) and detailed neuropsychological assessments (-63.2%), increased referrals and counseling (57.0%), and guided AD-related drug prescriptions (+88.4% and -50.0% in biomarker-positive and -negative cases, respectively). DISCUSSION: AD biomarker testing was associated with significant and positive changes in clinical management, including decreased health care resource use, therapy optimization, and increased patient and family member counseling. While certain changes in management were linked to the AD biomarker profile (e.g., referral to clinical trials), the majority of changes were independent of baseline clinical presentation and level of cognitive impairment, demonstrating a broad value for AD biomarker testing in individuals meeting the appropriate use criteria for testing.

Abstract Background The New Zealand (NZ) cicada fauna contains two co-distributed lineages that independently colonized the isolated continental fragment in the Miocene. One extensively studied lineage includes 90% of the extant species (Kikihia + Maoricicada + Rhodopsalta; ca 51 spp.), while the other contains just four extant species (Amphipsalta – 3 spp. + Notopsalta – 1 sp.) and has been little studied. We examined mitochondrial and nuclear-gene phylogenies and phylogeography, Bayesian relaxed-clock divergence timing (incorporating literature-based uncertainty of molecular clock estimates) and ecological niche models of the species from the smaller radiation. Results Mitochondrial and nuclear-gene trees supported the monophyly of Amphipsalta. Most interspecific diversification within Amphipsalta-Notopsalta occurred from the mid-Miocene to the Pliocene. However, interspecific divergence time estimates had large confidence intervals and were highly dependent on the assumed tree prior, and comparisons of uncorrected and patristic distances suggested difficulty in estimation of branch lengths. In contrast, intraspecific divergence times varied little across analyses, and all appear to have occurred during the Pleistocene. Two large-bodied forest taxa (A. cingulata, A. zelandica) showed minimal phylogeographic structure, with intraspecific diversification dating to ca. 0.16 and 0.37 Ma, respectively. Mid-Pleistocene-age phylogeographic structure was found within two smaller-bodied species (A. strepitans – 1.16 Ma, N. sericea – 1.36 Ma] inhabiting dry open habitats. Branches separating independently evolving species were long compared to intraspecific branches. Ecological niche models hindcast to the Last Glacial Maximum (LGM) matched expectations from the genetic datasets for A. zelandica and A. strepitans, suggesting that the range of A. zelandica was greatly reduced while A. strepitans refugia were more extensive. However, no LGM habitat could be reconstructed for A. cingulata and N. sericea, suggesting survival in microhabitats not detectable with our downscaled climate data. Conclusions Unlike the large and continuous diversification exhibited by the Kikihia-Maoricicada-Rhodopsalta clade, the contemporaneous Amphipsalta-Notopsalta lineage contains four comparatively old (early branching) species that show only recent diversification. This indicates either a long period of stasis with no speciation, or one or more bouts of extinction that have pruned the radiation. Within Amphipsalta-Notopsalta, greater population structure is found in dry-open-habitat species versus forest specialists. We attribute this difference to the fact that NZ lowland forests were repeatedly reduced in extent during glacial periods, while steep, open habitats likely became more available during late Pleistocene uplift.

Background: While previous studies have demonstrated the effect of Alzheimer's disease (AD) CSF testing in changing diagnosis, we lack an understanding of how this testing affects clinical management. Therefore, we assessed changes in clinical management associated with AD CSF biomarker testing when ordered as part of routine clinical management. Method: The 'Investigating the Impact of Alzheimer's Disease Diagnostics in British Columbia' (IMPACT‐AD BC) study (NCT05002699) is a longitudinal study examining the impact of AD CSF testing on clinical management, personal utility and health care economics in British Columbia, Canada. After AD CSF testing was ordered as part of routine care (where the clinical scenario met the appropriate use criteria), the patient and their physician were eligible to participate in the study. The primary outcome was the change in management (pre‐ v. post‐biomarker results) in a composite measure including 1) AD drug therapy, 2) other relevant drug therapy, 3) other diagnostic procedures, and 4) referral or counselling. Result: Participants (n = 129) had a median age of 63 (IQR:58‐68); 49% were female. Cognitive impairment at baseline consisted of 7% with subjective cognitive impairment, 53% with mild cognitive impairment, and 40% with dementia. CSF biomarker profiles were consistent with an amyloid‐beta pathology (i.e., A+) in 72% of cases. Changes in clinical management because of testing occurred in 83% of cases including: referrals and counseling (57%), imaging (47%) and other diagnostic procedures (e.g., neuropsychological testing) (42%), and use of AD drug therapies (40%). For those with a non‐AD pre‐biomarkers diagnosis, 42% were changed to AD post‐biomarkers; for those with an AD pre‐biomarkers diagnosis, 18% were changed to non‐AD post‐biomarkers. Conclusion: This study has revealed substantial changes in clinical management as a direct result of AD CSF biomarker testing in routine care. An understanding of the implications of biomarker testing will in turn help us: improve appropriate utilization, understand the broader impacts on persons living with dementia and on the health care system, and prepare for expanded use of this testing with the availability of disease‐modifying therapeutics. [ABSTRACT FROM AUTHOR]

Introduction: In the Investigating the Impact of Alzheimer's Disease Diagnostics in British Columbia (IMPACT-AD BC) study, we aimed to understand how Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarker testing-used in medical care-impacted medical decision-making (medical utility), personal decision-making (personal utility), and health system economics., Methods: The study was designed as an observational, longitudinal cohort study. A total of 149 patients were enrolled between February 2019 and July 2021. Patients referred to memory clinics were approached to participate if their dementia specialist ordered AD CSF biomarker testing as part of their routine medical care, and the clinical scenario met the appropriate use criteria for lumbar puncture and AD CSF biomarker testing. For the medical utility pillar, detailed clinical management plans were collected via physician questionnaires pre- and post-biomarker disclosure., Results: Patients with completed management questionnaires ( n = 142) had a median age of 64 (interquartile range: 59-69) years, 48% were female, and 60% had CSF biomarker profiles on the AD continuum. Clinical management changed in 89.4% of cases. AD biomarker testing was associated with decreased need for other diagnostic procedures, including brain imaging (-52.0%) and detailed neuropsychological assessments (-63.2%), increased referrals and counseling (57.0%), and guided AD-related drug prescriptions (+88.4% and -50.0% in biomarker-positive and -negative cases, respectively)., Discussion: AD biomarker testing was associated with significant and positive changes in clinical management, including decreased health care resource use, therapy optimization, and increased patient and family member counseling. While certain changes in management were linked to the AD biomarker profile (e.g., referral to clinical trials), the majority of changes were independent of baseline clinical presentation and level of cognitive impairment, demonstrating a broad value for AD biomarker testing in individuals meeting the appropriate use criteria for testing., Competing Interests: DY, JRB, CC, and CRF declare no conflicts of interest. Outside of the submitted work, the authors report the following disclosures. KJP reports speaker fees from Roche. PEL reports payment from Eli Lilly for presentation at an advisory board, and participation on an advisory board for Eisai. AHB reports grant funding from Green Valley (Shanghai), Intelgenx, ANAVEX, Cerevel, CABHI, and Victoria Hospitals Foundation; grant funding and personal fees from NovoNordisk and Roche; personal fees from Boehringer Ingelheim, Cowan Conference, and WestCoast Conference on Aging. DJF serves on the board of directors of the Canadians for Leading Edge Alzheimer Research (CLEAR) foundation. JAP reports an honorarium from Eisai for participation in a scientific advisory board meeting. HHF reports grant funding from Annovis, Vivoryon, AC Immune, Biohaven Pharmaceuticals, and LuMind; consulting with all payments made to the University of California San Diego (UCSD) with LuMind, Axon Neuroscience, Genentech, Roche/Banner, Tau Consortium, Biosplice Therapeutics, Novo Nordisk, Janssen Research & Development, and Arrowhead Pharmaceuticals; an issued patent with royalties paid (Detecting and Treating Dementia, PCT/US2007/07008); and a philanthropic donation to UCSD from the Epstein Family Alzheimer's Disease Collaboration. HBN reports consulting for Roche. GRH reports grant funding from Biogen, Roche, Cassava Sciences, and Eisai; consulting for Biogen, Roche, Novo Nordisk, Eisai, and Eli Lilly; GRH serves as President of the Consortium of Canadian Centres for Clinical Cognitive Research. MLD reports consulting for Siemens and Eisai, and consulting and lecturing fees from Roche. Author disclosures are available in the Supporting Information., (© 2024 The Authors. Alzheimer's & Dementia: Translational Research & Clinical Interventions published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)