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- Jansen, Willemijn J, et al.
(author)
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Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
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In: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
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Journal article (peer-reviewed)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
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- Bergviken Rensfeldt, Annika, 1969, et al.
(author)
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Akademiskt skrivande för doktorander – var och hur kan stödet ges?
- 2015
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In: HKG2015.
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Conference paper (other academic/artistic)abstract
- Doktorandarbetet innebär att brottas med teoretiska och metodologiska utmaningar samtidigt som det egna akademiska skrivandet ska utvecklas. De akademiska färdigheter som krävs för att färdigställa en avhandling och erövra en ”egen akademisk röst”, är därmed ett mödosamt arbete som ofta utmanar doktoranders självbild och självförtroende (Wellington 2010, Cotterall 2011). Trots ett stort behov av guidning ifråga om sin textproduktion, är det inte givet var/när doktorander ges stöd i sitt akademiska skrivande, eller hur stödet bör se ut. Vid detta rundabordssamtal ger vi exempel från två forskarutbildningskurser, en fakultetsgemensam kurs på svenska och en universitetsgemensam på engelska, där doktoranders textproduktion behandlas. Syftet med bidraget är att utifrån konkreta exempel initiera ett erfarenhetsutbyte kring sätt att möta doktorandbehovet av stöttning i sin skrivutveckling. Mer specifikt är frågan vilket pedagogiskt och institutionellt stöd detta kräver, eftersom doktorander förväntas ha kunskap om och behärska akademiskt skrivande inför sin doktorsexamen. Frågan är inte kopplad till handledares insatser i första hand. Snarare intresserar vi oss för hur doktorander kan komma samman i arbetsgrupper utanför vardagssammanhanget med handledare eller den egna forskningsgruppen. Vår erfarenhet är att doktorander genom kollegiala möten och inblick i andras avhandlingsskrivande får syn på sitt eget sätt att föra resonemang i text. Två frågor intresserar oss: •Vilka former av lärandeaktiviteter utmanar och stöttar doktoranders skrivutveckling? •Vilket institutionellt stöd för skrivutveckling behövs på utbildning på forskarnivå (och avancerad nivå)? Vilka för- och nackdelar har fakultets-/universitetsgemensamma kurser och resurser med inriktning mot skrivutveckling? Våra två kurser exemplifierar olika traditioner ifråga om skrivutvecklande pedagogik. Kursen i akademiskt skrivande på engelska vilar på en genrepedagogisk grund och betonar text i form av genrer och textproducerandets språkliga dimensioner (Swales and Feak 2014). Nära förknippat med kunskap om genrer är förståelse av olika discipliners typiska texter (Bruce 2013, Dressen-Hammouda 2008, Hyland 2014). Kursen i akademiskt skrivande på svenska bygger på antagandet om textproduktion som deltagande i social praktik (Kamler & Thomson 2014). Här betonas skrivande som ett sätt att närma sig det vetenskapliga samtalet, och att i ett forskningssammanhang kunna förstå premisser, dra slutsatser och kritiskt förhålla sig till forskningsdiskurser. En återkommande lärandeaktivitet är processkrivande genom kamratrespons (Caffarell & Barnett 2001). Inledningsvis presenteras respektive kurs utifrån lärandemål, lärandeaktiviteter och examinerande moment (20 min). Två pedagogiska utmaningar vi identifierat, bl a. via kursvärderingar, behandlas. Dels balansen mellan lärarintervention och självständighet, dels synliggörandet av det akademiska skrivandets praktik och villkor. Därefter inbjuds till gemensam diskussion kring de två frågorna (25 min). Referenser: Bruce, I. (2013). A role for genre-based pedagogy in academic writing instruction? An EAP perspective. TEXT Special Issue 21: Scores from another ground, 21, 1-15. http://hdl.handle.net/10289/8510 Caffarella, R S., and Barnett, B G. (2000). Teaching doctoral students to become scholarly writers: The importance of giving and receiving critiques. Studies in Higher Education 25, 39-51. Cotterall, S. (2011). Doctoral students writing: where's the pedagogy?, Teaching in Higher Education, 16(4), 413-425. Dressen-Hammouda, D. (2008). From novice to disciplinary expert: Disciplinary identity and genre mastery. English for Specific purposes, 27, 233–252. Hyland, K. (2014). Genre and writing instruction. LEARN Journal: Language Education and Acquisition Research Network, Special Issue 2014 From Research to Practice: New Perspectives in English Language Education, 40-49. Kamler, B., and Thomson, P. (2014, 2nd ed.). Helping doctoral students write: Pedagogies for supervision. London: Routledge. Paltridge, B. (2014). Genre and second-language academic writing. Language Teaching, 47(03), 303-318. Swales, J., and Feak, C. (2012). Academic writing for graduate students: essential tasks and skills. Ann Arbor: The University of Michigan Press. Wellington, J. (2010). More than a matter of cognition: An exploration of affective writing problems of post-graduate students and their possible solutions. Teaching in Higher Education 15, 135-150.
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- Sator, Lea, et al.
(author)
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Overdiagnosis of COPD in Subjects With Unobstructed Spirometry A BOLD Analysis
- 2019
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 156:2, s. 277-288
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Journal article (peer-reviewed)abstract
- BACKGROUND: There are several reports on underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012.METHODS: A false positive diagnosis of COPD was considered when participants reported a doctor's diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC < 0.7).RESULTS: Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a subgroup analysis excluding participants who reported a diagnosis of "chronic bronchitis" or "emphysema" (n = 220), 37.7% had no airflow limitation. The site-specific prevalence of false positive COPD varied greatly, from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education; former and current smoking; the presence of wheeze, cough, and phlegm; and concomitant medical diagnosis of asthma or heart disease. Among the subjects with false positive COPD, 45.7% reported current use of respiratory medication. Excluding patients with reported asthma, 34.4% of those with normal spirometry still used a respiratory medication.CONCLUSIONS: False positive COPD is frequent. This might expose nonobstructed subjects to possible adverse effects of respiratory medication.
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