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1.
BMC Psychiatry ; 24(1): 223, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38515091

RESUMEN

BACKGROUND: Somatisation is a highly prevalent psychiatric syndrome in both women and men, in which psychological distress is manifested in physical symptoms without a medical explanation. Many patients with somatisation disorder are high healthcare utilisers, particularly at emergency departments. Unnecessary investigations and diagnostic operations occur frequently, which cause both patient suffering and a significant burden on the healthcare system. Emergency department physicians' awareness of somatisation and its manifestations has not previously been studied. This study aimed to investigate awareness about somatisation disorder among physicians working at emergency departments in western Sweden, and to explore differences between gender, specialty, and work experience. METHODS: A web-based, cross-sectional survey consisting of six dichotomous questions about somatisation disorder was conducted, in December 2021 - January 2022, among licensed physicians of various specialties working at emergency departments in western Sweden. Descriptive analyses and comparative analyses were performed to investigate differences between gender, type of specialty, and years of practice. Data were analysed using chi2 tests and Fisher's exact test. RESULTS: Of the 526 eligible physicians who received the survey, 241 responded; response rate 45.8%. The majority of the respondents (56.4%) were women, and most (35.3%) were specialised in obstetrics/gynaecology. Average years of work experience was 11.1 (SD 8.7) years. Although 71% of respondents were aware of the diagnosis, only 7% knew the diagnostic criteria and only 6% had ever diagnosed a patient with somatisation disorder. Female physicians were more aware of underlying factors than their male colleagues (55.7% vs. 38.2%; p = .010). Type of specialty or years of practice did not affect awareness. CONCLUSIONS: Awareness of somatisation disorder is low among physicians working at emergency departments in western Sweden. The findings suggest a need to increase awareness and knowledge and provide training in diagnosing the condition, to ensure correct decisions and optimal patient management. Clinical guidelines need to be developed to support diagnosis, investigation, and treatment, in Sweden as well as internationally.


Asunto(s)
Medicina , Médicos , Humanos , Masculino , Femenino , Estudios Transversales , Suecia , Servicio de Urgencia en Hospital , Encuestas y Cuestionarios , Médicos/psicología
2.
Scand J Public Health ; 52(3): 354-359, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38516905

RESUMEN

AIM: The aim of this study was to investigate a cohort of Swedish eighth graders' mental health and experiences during the COVID-19 pandemic. METHODS: Participants were 157 eighth graders recruited in junior high schools during 2020 who completed a depression questionnaire and a survey about their psychosocial health in relation to the COVID-19 pandemic, alongside a follow-up assessment in 2021. Analyses were conducted using latent change score and cross-lagged models. RESULTS: Participants' depressive symptoms did not substantially increase during the COVID-19 pandemic. The level of depressive symptoms in 2020 was significantly associated with participants' perceptions of the pandemic in 2020 and spring 2021. Participants with higher depression scores reported worse experiences of the pandemic. CONCLUSIONS: The stable level of depressive symptoms among this cohort of eighth graders suggested that keeping schools open during a nationwide lockdown could mitigate some mental health consequences. Adolescents in this study with higher self-assessed depressive symptoms were more likely to experience increased depression after 6 months and had worse experiences during the pandemic than others. This suggests that the pandemic may not immediately affect mental well-being, but those at risk may be affected over time.


Asunto(s)
COVID-19 , Depresión , Salud Mental , Humanos , COVID-19/prevención & control , COVID-19/epidemiología , Suecia/epidemiología , Adolescente , Masculino , Femenino , Estudios Longitudinales , Depresión/epidemiología , Estudios de Cohortes , Pandemias/prevención & control , Encuestas y Cuestionarios
3.
Scand J Prim Health Care ; 42(1): 61-71, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38047631

RESUMEN

INTRODUCTION: Swedish Physical Activity on Prescription (PAP) has been shown to increase physical activity levels, which is known to lead to positive health effects. PAP is being implemented in Swedish healthcare to various extents. However, there is a lack of knowledge about how Swedish general practitioners (GPs) work with PAP and what hinders and facilitates wider implementation. AIMS: This study aimed to survey GPs' use and views of PAP, identify barriers and facilitators for implementing PAP, and explore associations to gender, practice location, and experience. METHODS: The study was framed by the Normalization Process Theory. A survey was sent to 463 GPs at 69 different healthcare centres in Region Västra Götaland. Data were analysed using multiple logistic and linear regressions. RESULTS: A total of 143 GPs completed the survey (response rate 31%). Views on PAP were generally positive amongst respondents, but only 27% reported using PAP regularly. The most prominent reported barriers were insufficient training and resources. Positive views and willingness to collaborate in using PAP were identified as facilitators. Responding GPs in Gothenburg used PAP more often (OR 6.4; 95% CI 2.7-14.8) and were significantly more positive to the method than GPs in other areas of the region. GPs with more than 10 years of practice used PAP more often (OR 2.5; 95% CI 1.1-6.0) than less experienced GPs. Few of the investigated variables were associated with gender. CONCLUSIONS: The positive views amongst responding GPs are helpful, but more education, training and resources are needed for successful implementation of PAP in Swedish primary health care.


Implementation of physical activity on prescription (PAP) in Swedish healthcare has been ongoing for many years, but is implemented to various extents across and within regions.Views on PAP are generally positive, but use is not widespread amongst general practitioners in Region Västra Götaland who responded to the survey.The method is more frequently used in Gothenburg, where the most extensive implementation work has been done, and amongst more experienced general practitioners.Education and training in using PAP need to increase for successful implementation.


Asunto(s)
Médicos Generales , Humanos , Suecia , Actitud del Personal de Salud , Encuestas y Cuestionarios , Ejercicio Físico , Atención Primaria de Salud , Prescripciones
4.
Acta Psychiatr Scand ; 148(4): 327-337, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37415523

RESUMEN

OBJECTIVE: Mental illness is increasing among young people and likewise the request for health care services. At the same time, somatic comorbidity is common in children and adolescents with psychiatric disorders. There is a lack of studies on health care use in children and adolescents, and the hypothesis was that children and adolescents with psychiatric disorders use more primary-, and specialized somatic health care compared to children without psychiatric disorders. METHODS: In this retrospective population-based register study, all individuals aged 3-17 years living in Västra Götaland region in Sweden in 2017 were included (n = 298,877). Linear and Poisson regression were used to compare health care use during 2016-2018 between children with and without psychiatric diagnoses, controlling for age and gender. The results were reported as unstandardised beta coefficient (ß) and adjusted prevalence ratio (aPR) respectively. RESULTS: Having a psychiatric diagnosis was associated with more primary care visits (ß 2.35, 95% CI 2.30-2.40). This applied to most diagnoses investigated. Girls had more primary care visits than boys. Likewise, individuals with psychiatric diagnoses had more specialized somatic outpatient care (ß 1.70, 95% CI 1.67-1.73), both planned and unplanned (ß 1.23, 95% CI 1.21-1.25; ß 0.18, 95% CI 0.17-0.19). Somatic inpatient care was more common in those having a psychiatric diagnosis (aPR 1.65, 95% CI 1.58-1.72), with the diagnoses of psychosis and substance use exerting the greatest risk. CONCLUSIONS: Psychiatric diagnoses were associated with increased primary-, somatic outpatient- as well as somatic inpatient care. Increased awareness of comorbidity and easy access to relevant health care could be beneficial for patients and caregivers. The results call for a review of current health care systems with distinct division between medical disciplines and levels of health care.


Asunto(s)
Trastornos Mentales , Trastornos Psicóticos , Adolescente , Niño , Femenino , Humanos , Masculino , Comorbilidad , Atención a la Salud , Trastornos Mentales/epidemiología , Trastornos Mentales/terapia , Trastornos Mentales/diagnóstico , Aceptación de la Atención de Salud , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/terapia , Estudios Retrospectivos
5.
Int Psychogeriatr ; 30(7): 981-990, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29108523

RESUMEN

ABSTRACTBackground:A recently published study suggests that Gamma-Glutamyltransferase (GGT) in midlife is related to an increased risk of dementia. In the present longitudinal study, we explore the effects of serum GGT on cognitive decline and dementia also in more advanced ages. METHODS: We analyzed GGT in a sample of 452 individuals, aged 80 years and older at baseline, with the purpose to explore subsequent effects on cognitive performance. We specifically modeled GGT to cognitive change, time to death, and dementia. RESULTS: Our main finding is that a higher level of GGT is associated with cognitive decline prior to death and vascular dementia in late life. These findings were evident across cognitive domains. CONCLUSIONS: This is the first longitudinal study to report on significant associations in late life between GGT, cognitive performance and dementia. Further research is needed to examine the underlying mechanisms of GGT as a marker of age-related cognitive decline.


Asunto(s)
Cognición/fisiología , Disfunción Cognitiva , Demencia Vascular , gamma-Glutamiltransferasa/sangre , Anciano de 80 o más Años , Biomarcadores/sangre , Disfunción Cognitiva/sangre , Disfunción Cognitiva/diagnóstico , Correlación de Datos , Demencia Vascular/sangre , Demencia Vascular/diagnóstico , Femenino , Humanos , Estudios Longitudinales , Masculino , Pruebas Neuropsicológicas , Factores de Riesgo , Suecia/epidemiología , Cuidado Terminal
6.
Magn Reson Med ; 75(1): 390-402, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25604436

RESUMEN

PURPOSE: Models based on a sum of damped exponentials occur in many applications, particularly in multicomponent T2 relaxometry. The problem of estimating the relaxation parameters and the corresponding amplitudes is known to be difficult, especially as the number of components increases. In this article, the commonly used non-negative least squares spectrum approach is compared to a recently published estimation algorithm abbreviated as Exponential Analysis via System Identification using Steiglitz-McBride. METHODS: The two algorithms are evaluated via simulation, and their performance is compared to a statistical benchmark on precision given by the Cramér-Rao bound. By applying the algorithms to an in vivo brain multi-echo spin-echo dataset, containing 32 images, estimates of the myelin water fraction are computed. RESULTS: Exponential Analysis via System Identification using Steiglitz-McBride is shown to have superior performance when applied to simulated T2 relaxation data. For the in vivo brain, Exponential Analysis via System Identification using Steiglitz-McBride gives an myelin water fraction map with a more concentrated distribution of myelin water and less noise, compared to non-negative least squares. CONCLUSION: The Exponential Analysis via System Identification using Steiglitz-McBride algorithm provides an efficient and user-parameter-free alternative to non-negative least squares for estimating the parameters of multiple relaxation components and gives a new way of estimating the spatial variations of myelin in the brain.


Asunto(s)
Algoritmos , Agua Corporal/metabolismo , Encéfalo/metabolismo , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Vaina de Mielina/metabolismo , Adulto , Encéfalo/ultraestructura , Femenino , Humanos , Vaina de Mielina/ultraestructura , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
Magn Reson Med ; 72(3): 880-92, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24166591

RESUMEN

PURPOSE: The balanced steady-state free precession (bSSFP) pulse sequence has shown to be of great interest due to its high signal-to-noise ratio efficiency. However, bSSFP images often suffer from banding artifacts due to off-resonance effects, which we aim to minimize in this article. METHODS: We present a general and fast two-step algorithm for 1) estimating the unknowns in the bSSFP signal model from multiple phase-cycled acquisitions, and 2) reconstructing band-free images. The first step, linearization for off-resonance estimation (LORE), solves the nonlinear problem approximately by a robust linear approach. The second step applies a Gauss-Newton algorithm, initialized by LORE, to minimize the nonlinear least squares criterion. We name the full algorithm LORE-GN. RESULTS: We derive the Cramér-Rao bound, a theoretical lower bound of the variance for any unbiased estimator, and show that LORE-GN is statistically efficient. Furthermore, we show that simultaneous estimation of T1 and T2 from phase-cycled bSSFP is difficult, since the Cramér-Rao bound is high at common signal-to-noise ratio. Using simulated, phantom, and in vivo data, we illustrate the band-reduction capabilities of LORE-GN compared to other techniques, such as sum-of-squares. CONCLUSION: Using LORE-GN we can successfully minimize banding artifacts in bSSFP.


Asunto(s)
Artefactos , Mapeo Encefálico/métodos , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Algoritmos , Simulación por Computador , Humanos , Método de Montecarlo , Fantasmas de Imagen
8.
Gerontologist ; 63(2): 274-284, 2023 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-35876786

RESUMEN

BACKGROUND AND OBJECTIVES: Although interest in sexuality in older age has increased over the last decades, few studies have focused on longitudinal change in sexual satisfaction around retirement age. In the present study, we studied change in sexual satisfaction across retirement in a sample of Swedish older adults with a partner. RESEARCH DESIGN AND METHODS: Our analyses were based on n = 759 participants (359 male, 400 female) from the longitudinal Health, Aging, and Retirement Transitions in Sweden study. For this study, we used 5 waves spanning over a period of 4 years. RESULTS: On average, sexual satisfaction did not change significantly before retirement, but decreased after retirement. Interestingly, women showed higher sexual satisfaction than men, as well as a more positive development of both pre- and postretirement sexual satisfaction. Individuals with higher relationship satisfaction had a higher sexual satisfaction until retirement, but their sexual satisfaction also decreased faster after retirement, whereas those with lower relationship satisfaction showed a stable but lower sexual satisfaction. DISCUSSION AND IMPLICATIONS: Sexual satisfaction can change in the retirement transition in several important ways and further studies on the impact of retirement and other late-life stage transitions are warranted.


Asunto(s)
Orgasmo , Jubilación , Humanos , Masculino , Femenino , Anciano , Conducta Sexual , Envejecimiento , Sexualidad , Satisfacción Personal
9.
Phys Ther ; 103(1)2022 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-36326139

RESUMEN

OBJECTIVE: The purpose of this study was to evaluate whether the clinical assessment of pelvic floor muscles and the diastasis recti abdominis could predict the severity of pelvic girdle pain during the first year postpartum. METHODS: Between 2018 and 2020, 504 women were recruited to this prospective longitudinal cohort study. At 2 to 3 months postpartum, their pelvic floor muscles and diastasis recti abdominis were assessed using vaginal palpation, observation, and caliper measurement. The participants completed the Pelvic Girdle Questionnaire (PGQ) at 2 to 3, 6, 9, and 12 months postpartum. Mixed-effect models were used to determine how the results of pelvic floor muscle and diastasis recti abdominis assessments predicted the PGQ score. A sub-analysis for middle to high PGQ scores was conducted. RESULTS: Maximal voluntary pelvic floor muscle contractions ≥3 (Modified Oxford Scale, scored from 0 to 5) predicted a decreased PGQ score (ß = -3.13 [95% CI = -5.77 to -0.48]) at 2 to 3 months postpartum, with a higher prediction of a middle to high PGQ score (ß = -6.39). Diastasis recti abdominis width did not have any significant correlation with the PGQ score. A sub-analysis showed that a diastasis recti abdominis width ≥35 mm predicted an increased PGQ score (ß = 5.38 [95% CI = 1.21 to 9.55]) in women with pelvic girdle pain. CONCLUSION: The distinction between weak and strong maximal voluntary pelvic floor muscle contractions is an important clinical assessment in women with postpartum pelvic girdle pain. The exact diastasis recti abdominis width, measured in millimeters, showed no clinical relevance. However, a diastasis recti abdominis width ≥35 mm was associated with a higher PGQ score, and further research about this cutoff point in relation to pain is needed. IMPACT: This study highlights the importance of clinical assessment of pelvic floor muscles in patients with postpartum pelvic girdle pain. A better understanding of the role of this muscle group will enable more effective physical therapist treatment of pelvic girdle pain.


Asunto(s)
Diástasis Muscular , Dolor de Cintura Pélvica , Humanos , Femenino , Dolor de Cintura Pélvica/diagnóstico , Estudios Prospectivos , Estudios Longitudinales , Periodo Posparto , Diafragma Pélvico
10.
PLoS One ; 17(10): e0276868, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36315564

RESUMEN

BACKGROUND: Increased physical activity (PA) has positive effects on health and longevity. In Swedish healthcare, the physical activity on prescription (PAP) method reportedly increases patients' PA levels for up to 12 months, but long-term follow ups are lacking. As it remains difficult to maintain lifestyle changes, our aim was to evaluate adherence and clinical effects at a 5-year follow-up of PAP treatment in primary healthcare. METHODS: This longitudinal, prospective cohort study included 444 patients, (56% female), aged 27-85 years, with at least one metabolic risk factor. Participants were offered PAP by nurses or physiotherapists. The PAP intervention included an individualised dialogue, a PA recommendation by written prescription, and individually adjusted follow-up over 5 years, according to the Swedish PAP model. Patient PA level, metabolic risk factors, and health related quality of life (HRQoL) were measured at baseline and at the 6-month, 1.5-year, 2.5-year, 3.5-year, and 5-year follow-ups. Estimated latent growth curves were used to examine levels and rates of change in the outcomes. RESULTS: The study dropout rate was 52%, with 215 of 444 patients completing the 5-year follow-up. At follow-up, the mean PA level had increased by 730 MET-minutes per week or 3 hours of moderate-intensity PA/week when compared to baseline. During the 5-year intervention, we observed significant positive changes (p ≤ 0.05) in 9 of 11 metabolic risk factors and HRQoL parameters: body mass index, waist circumference, systolic and diastolic blood pressure, fasting plasma glucose, triglycerides, cholesterol, high-density lipoprotein, and mental component summary. CONCLUSION: This first evaluation of a 5-year PAP intervention in primary care demonstrated positive long-term (5 years) effects regarding PA level, metabolic health, and HRQoL. The recorded long-term adherence was ~50%, which is in line with medical treatment. Despite limitations, PAP can have long-term effects in an ordinary primary care setting.


Asunto(s)
Ejercicio Físico , Calidad de Vida , Humanos , Femenino , Masculino , Estudios Prospectivos , Prescripciones , Factores de Riesgo
11.
J Gerontol B Psychol Sci Soc Sci ; 76(2): 229-241, 2021 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-31187137

RESUMEN

OBJECTIVE: Handgrip strength, an indicator of overall muscle strength, has been found to be associated with slower rate of cognitive decline and decreased risk for cognitive impairment and dementia. However, evaluating the replicability of associations between aging-related changes in physical and cognitive functioning is challenging due to differences in study designs and analytical models. A multiple-study coordinated analysis approach was used to generate new longitudinal results based on comparable construct-level measurements and identical statistical models and to facilitate replication and research synthesis. METHODS: We performed coordinated analysis on 9 cohort studies affiliated with the Integrative Analysis of Longitudinal Studies of Aging and Dementia (IALSA) research network. Bivariate linear mixed models were used to examine associations among individual differences in baseline level, rate of change, and occasion-specific variation across grip strength and indicators of cognitive function, including mental status, processing speed, attention and working memory, perceptual reasoning, verbal ability, and learning and memory. Results were summarized using meta-analysis. RESULTS: After adjustment for covariates, we found an overall moderate association between change in grip strength and change in each cognitive domain for both males and females: Average correlation coefficient was 0.55 (95% CI = 0.44-0.56). We also found a high level of heterogeneity in this association across studies. DISCUSSION: Meta-analytic results from nine longitudinal studies showed consistently positive associations between linear rates of change in grip strength and changes in cognitive functioning. Future work will benefit from the examination of individual patterns of change to understand the heterogeneity in rates of aging and health-related changes across physical and cognitive biomarkers.


Asunto(s)
Envejecimiento , Cognición/fisiología , Disfunción Cognitiva , Evaluación Geriátrica/métodos , Fuerza de la Mano , Anciano , Envejecimiento/fisiología , Envejecimiento/psicología , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/psicología , Femenino , Humanos , Pruebas de Inteligencia , Estudios Longitudinales , Masculino , Medición de Riesgo/métodos
12.
J Gerontol A Biol Sci Med Sci ; 74(11): 1793-1804, 2019 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-30825374

RESUMEN

BACKGROUND: Substantial research is dedicated to understanding the aging-related dynamics among individual differences in level, change, and variation across physical and cognitive abilities. Evaluating replicability and synthesizing these findings has been limited by differences in measurements and samples, and by study design and statistical analyses confounding between-person differences with within-person changes. In this article, we conducted a coordinated analysis and summary meta-analysis of new results on the aging-related dynamics linking pulmonary function and cognitive performance. METHODS: We performed coordinated analysis of bivariate growth models in data from 20,586 participants across eight longitudinal studies to examine individual differences in baseline level, rate of change, and occasion-specific variability in pulmonary and cognitive functioning. Results were summarized using meta-analysis. RESULTS: We found consistent but weak baseline and longitudinal associations in levels of pulmonary and cognitive functioning, but no associations in occasion-specific variability. CONCLUSIONS: Results provide limited evidence for a consistent link between simultaneous changes in pulmonary and cognitive function in a normal aging population. Further research is required to understand patterns of onset of decline and differences in rates of change within and across physical and cognitive functioning domains, both within-individuals and across countries and birth cohorts. Coordinated analysis provides an efficient and rigorous approach for replicating and comparing results across independent longitudinal studies.


Asunto(s)
Envejecimiento/fisiología , Envejecimiento/psicología , Trastornos del Conocimiento/epidemiología , Enfermedades Pulmonares/epidemiología , Pruebas de Función Respiratoria , Factores de Edad , Anciano , Anciano de 80 o más Años , Trastornos del Conocimiento/fisiopatología , Comorbilidad , Femenino , Humanos , Estudios Longitudinales , Enfermedades Pulmonares/fisiopatología , Mediciones del Volumen Pulmonar , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Prevalencia , Pronóstico , Medición de Riesgo , Factores Sexuales , Capacidad Vital
13.
IEEE Trans Med Imaging ; 37(11): 2414-2427, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29993537

RESUMEN

In quantitative magnetic resonance mapping, the variable flip angle (VFA) steady state spoiled gradient recalled echo (SPGR) imaging technique is popular as it provides a series of high resolution weighted images in a clinically feasible time. Fast, linear methods that estimate maps from these weighted images have been proposed, such as DESPOT1 and iterative re-weighted linear least squares. More accurate, non-linear least squares (NLLS) estimators are in play, but these are generally much slower and require careful initialization. In this paper, we present NOVIFAST, a novel NLLS-based algorithm specifically tailored to VFA SPGR mapping. By exploiting the particular structure of the SPGR model, a computationally efficient, yet accurate and precise map estimator is derived. Simulation and in vivo human brain experiments demonstrate a twenty-fold speed gain of NOVIFAST compared with conventional gradient-based NLLS estimators while maintaining a high precision and accuracy. Moreover, NOVIFAST is eight times faster than the efficient implementations of the variable projection (VARPRO) method. Furthermore, NOVIFAST is shown to be robust against initialization.


Asunto(s)
Algoritmos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Encéfalo/diagnóstico por imagen , Humanos , Masculino , Fantasmas de Imagen
14.
Neurobiol Aging ; 38: 68-72, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26827644

RESUMEN

An association between level of cognitive function and grip strength is well established, whereas evidence for longitudinal associations of change in the 2 functions is still unclear. We examined associations between cognition and grip strength in levels of performance and in longitudinal change in late life in a population-based sample, aged ≥80 years at baseline, followed until death. The sample consisted of 449 nondemented individuals drawn from the OCTO-Twin Study. A test battery assessing 6 cognitive domains and grip strength was administered at 5 occasions with measurements intervals of 2 years. We fitted time to death bivariate growth curve models, adjusted for age, education, and sex which resulted in associations between grip strength and cognition in both levels of performance (across all cognitive domains) and rates of change (in 4 of 6 domains). These results show that cognition and grip strength change conjointly in later life and that the association between cognition and grip strength is stronger before death than earlier in life.


Asunto(s)
Envejecimiento/fisiología , Envejecimiento/psicología , Cognición/fisiología , Muerte , Fuerza de la Mano/fisiología , Anciano de 80 o más Años , Femenino , Humanos , Estudios Longitudinales , Masculino , Factores de Tiempo
15.
J Magn Reson ; 249: 100-107, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25462953

RESUMEN

Estimation of the transverse relaxation time, T2, from multi-echo spin-echo images is usually performed using the magnitude of the noisy data, and a least squares (LS) approach. The noise in these magnitude images is Rice distributed, which can lead to a considerable bias in the LS-based T2 estimates. One way to avoid this bias problem is to estimate a real-valued and Gaussian distributed dataset from the complex data, rather than using the magnitude. In this paper, we propose two algorithms for phase correction which can be used to generate real-valued data suitable for LS-based parameter estimation approaches. The first is a Weighted Linear Phase Estimation algorithm, abbreviated as WELPE. This method provides an improvement over a previously published algorithm, while simplifying the estimation procedure and extending it to support multi-coil input. The algorithm fits a linearly parameterized function to the multi-echo phase-data in each voxel and, based on this estimated phase, projects the data onto the real axis. The second method is a maximum likelihood estimator of the true decaying signal magnitude, which can be efficiently implemented when the phase variation is linear in time. The performance of the algorithms is demonstrated via Monte Carlo simulations, by comparing the accuracy of the estimates. Furthermore, it is shown that using one of the proposed algorithms enables more accurate T2 estimates; in particular, phase corrected data significantly reduces the estimation bias in multi-component T2 relaxometry example, compared to when using magnitude data. WELPE is also applied to a 32-echo in vivo brain dataset, to show its practical feasibility.

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