| 1. |
- Schmidt, R., et al.
(författare)
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White Matter Lesion Progression in LADIS Frequency, Clinical Effects, and Sample Size Calculations
- 2012
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 43:10, s. 2643-2647
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose-White matter lesion (WML) progression has been advocated as a surrogate marker in intervention trials on cerebral small vessel disease. We assessed the rate of visually rated WML progression, studied correlations between lesion progression and cognition, and estimated sample sizes for clinical trials with pure WML progression vs combined WML progression-cognitive outcomes. Methods-Those 394 participants of the Leukoaraiosis and Disability Study (LADIS) study with magnetic resonance imaging scanning at baseline and 3-year follow-up were analyzed. WML progression rating relied on the modified Rotterdam Progression Scale. The Vascular Dementia Assessment Scale global score and a composite score of specific executive function tests assessed longitudinal change in cognition. Sample size calculations were based on the assumption that treatment reduces WML progression by 1 grade on the Rotterdam Progression Scale. Results-WML progression related to deterioration in cognitive functioning. This relationship was less pronounced in subjects with early confluent and confluent lesions. Consequently, studies in which the outcome is cognitive change resulting from treatment effects on lesion progression will need between 1809 subjects per treatment arm when using executive tests and up to 18 853 subjects when using the Vascular Dementia Assessment Scale score. Studies having WML progression as the sole outcome will need only 58 or 70 individuals per treatment arm. Conclusions-WML progression is an interesting outcome for proof-of-concept studies in cerebral small vessel disease. If cognitive outcome measures are added to protocols, then sample size estimates increase substantially. Our data support the use of an executive test battery rather than the Vascular Dementia Assessment Scale as the primary cognitive outcome measure. (Stroke. 2012; 43:2643-2647.)
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| 2. |
- Firbank, M. J., et al.
(författare)
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Relationship between progression of brain white matter changes and late-life depression: 3-year results from the LADIS study
- 2012
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Ingår i: British Journal of Psychiatry. - : Royal College of Psychiatrists. - 0007-1250 .- 1472-1465. ; 201:1, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- Background Brain white matter changes (WMC) and depressive symptoms are linked, but the directionality of this association remains unclear. Aims To investigate the relationship between baseline and incident depression and progression of white matter changes. Method In a longitudinal multicentre pan-European study (Leukoaraiosis and Disability in the elderly, LADIS), participants aged over 64 underwent baseline magnetic resonance imaging (MRI) and clinical assessments. Repeat scans were obtained at 3 years. Depressive outcomes were assessed in terms of depressive episodes and the Geriatric Depression Scale (GDS). Progression of WMC was measured using the modified Rotterdam Progression scale. Results Progression of WMC was significantly associated with incident depression during year 3 of the study (P = 0.002) and remained significant after controlling for transition to disability, baseline WMC and baseline history of depression. There was no significant association between progression of WMC and GDS score, and no significant relationship between progression of WMC and history of depression at baseline. Conclusions Our results support the vascular depression hypothesis and implicate WMC as causal in the pathogenesis of late-life depression.
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| 3. |
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| 4. |
- Verdelho, A., et al.
(författare)
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Physical Activity Prevents Progression for Cognitive Impairment and Vascular Dementia Results From the LADIS (Leukoaraiosis and Disability) Study
- 2012
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 43:12, s. 3331-3335
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose-We aimed to study if physical activity could interfere with progression for cognitive impairment and dementia in older people with white matter changes living independently. Methods-The LADIS (Leukoaraiosis and Disability) prospective multinational European study evaluates the impact of white matter changes on the transition of independent elderly subjects into disability. Subjects were evaluated yearly during 3 years with a comprehensive clinical protocol and cognitive assessment with classification of cognitive impairment and dementia according to usual clinical criteria. Physical activity was recorded during the clinical interview. MRI was performed at entry and at the end of the study. Results-Six hundred thirty-nine subjects were included (74.1 +/- 5 years old, 55% women, 9.6 +/- 3.8 years of schooling, 64% physically active). At the end of follow-up, 90 patients had dementia (vascular dementia, 54; Alzheimer disease with vascular component, 34; frontotemporal dementia, 2), and 147 had cognitive impairment not dementia. Using Cox regression analysis, physical activity reduced the risk of cognitive impairment (dementia and not dementia: beta=-0.45, P=0.002; hazard ratio, 0.64; 95% CI, 0.48-0.85), dementia (beta=-0.49, P=0.043; hazard ratio, 0.61; 95% CI, 0.38-0.98), and vascular dementia (beta=-0.86, P=0.008; hazard ratio, 0.42; 95% CI, 0.22-0.80), independent of age, education, white matter change severity, medial temporal atrophy, previous and incident stroke, and diabetes. Conclusions-Physical activity reduces the risk of cognitive impairment, mainly vascular dementia, in older people living independently. (Stroke. 2012; 43: 3331-3335.)
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| 5. |
- Russu, A., et al.
(författare)
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Joint Modeling of Efficacy, Dropout, and Tolerability in Flexible-Dose Trials : A Case Study in Depression
- 2012
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Ingår i: Clinical Pharmacology and Therapeutics. - : Springer Science and Business Media LLC. - 0009-9236 .- 1532-6535. ; 91:5, s. 863-871
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Tidskriftsartikel (refereegranskat)abstract
- Many difficulties may arise during the modeling of the time course of Hamilton Rating Scale for Depression (HAM D) scores in clinical trials for the evaluation of antidepressant drugs: (i) flexible designs, used to increase the chance of selecting more efficacious doses, (ii) dropout events, and (iii) adverse effects related to the experimental compound. It is crucial to take into account all these factors when designing an appropriate model of the HAM D time course and to obtain a realistic description of the dropout process. In this work, we propose an integrated approach to the modeling of a double-blind, flexible-dose, placebo-controlled, phase II depression trial that comprises response, tolerability, and dropout. We investigate three different dropout mechanisms in terms of informativeness. Goodness of fit is quantitatively assessed with respect to response (HAM D score) and dropout data. We show that dropout is a complex phenomenon that may be influenced by HAM D evolution, dose changes, and occurrence of drug-related adverse effects.
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