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Objective: Movement enables animals to complete their life history by responding to changing environmental conditions. Linking movement behaviors to life history characteristics can allow more targeted management applications for declining native fish populations. We identified seasonal movement patterns of Roundtail Chub Gila robusta and Flannelmouth Sucker Catostomus latipinnis, two understudied species that currently occupy only a portion of their historical range in the Colorado River basin. Methods: We coupled passive integrated transponder tag antenna systems with multistate capture–recapture models to quantify juvenile and adult movement between main‐stem and tributary habitats in the Blacks Fork subbasin of southwestern Wyoming during 2019–2021. We also evaluated how flow and temperature may cue the timing of seasonal movements. Result: Adults from both species made spring movements, likely associated with spawning, to reach upstream tributary habitat, though adult Flannelmouth Sucker movements were more common and longer. Roundtail Chub primarily moved into the Hams Fork, while Flannelmouth Sucker primarily moved into Muddy Creek, an intermittent tributary that was also identified as important for juvenile rearing. Juvenile movements occurred primarily during the fall months, with distance traveled comparable between species. Temperature and flow influenced the timing of spring movements for adult Flannelmouth Sucker, with rising temperatures triggering movement and low flow potentially limiting access to preferred spawning habitat. Conclusion: Identified movements likely contribute to Roundtail Chub and Flannelmouth Sucker persistence in this highly altered stream system and ultimately provide insights for management and recovery strategies to prevent further population declines. Impact statementNative fish make seasonal movements into tributary habitats that likely allow them to track habitat suitable for spawning and juvenile rearing. [ABSTRACT FROM AUTHOR]

The function of cellobiose dehydrogenase (CDH) in biosensors, biofuel cells, and as a physiological redox partner of lytic polysaccharide monooxygenase (LPMO) is based on its role as an electron donor. Before donating electrons to LPMO or electrodes, an interdomain electron transfer from the catalytic FAD-containing dehydrogenase domain to the electron shuttling cytochrome domain of CDH is required. This study investigates the role of two crucial amino acids located at the dehydrogenase domain on domain interaction and interdomain electron transfer by structure-based engineering. The electron transfer kinetics of wild-type Myriococcum thermophilum CDH and its variants M309A, R698S, and M309A/R698S were analyzed by stopped-flow spectrophotometry and structural effects were studied by small-angle X-ray scattering. The data show that R698 is essential to pull the cytochrome domain close to the dehydrogenase domain and orient the heme propionate group towards the FAD, while M309 is an integral part of the electron transfer pathway - its mutation reducing the interdomain electron transfer 10-fold. Structural models and molecular dynamics simulations pinpoint the action of these two residues on the domain interaction and interdomain electron transfer.

Abstract The equilibrium theorem provided a fundamental framework for understanding species’ distributions and movement in fragmented ecosystems. Wetland-dependent avian species are model organisms to test insular predictions within protected area networks because their mobility allows surveillance of isolated patches without landscape barriers. We hypothesized size and isolation would influence functional connectivity of sanctuaries by GPS-marked wintering mallards (Anas platyrhynchos) within a mesocosm protected sanctuary area network. We evaluated functional connectivity and sanctuary use, measured by movements between sanctuaries, using a multistate modeling framework. Proximity drove connectivity, underscoring that patch isolation—not size—influenced connectivity, even for an avian species with no ascertainable landscape resistance or barriers. We also found that sanctuary use increased overwintering survival by reducing harvest mortality. Our test of equilibrium theory predictions demonstrated that isolation of protected sanctuary areas supersedes their size in determining functional connectivity for mallards and access to these areas may have direct fitness consequences. Our findings could refine land acquisition, restoration, and management practices with equal or greater emphasis on adjacency in protected area network design, especially for wetland-dependent migratory gamebirds.

Objectives To better understand variations in multimorbidity severity over time, we estimate disability-free and disabling multimorbid life expectancy (MMLE), comparing Costa Rica, Mexico, and the United States (US). We also assess MMLE inequalities by sex and education. Methods Data come from the Costa Rican Study on Longevity and Healthy Aging (2005–2009), the Mexican Health and Aging Study (2012–2018), and the Health and Retirement Study (2004–2018). We apply an incidence-based multistate Markov approach to estimate disability-free and disabling MMLE and stratify models by sex and education to study within-country heterogeneity. Multimorbidity is defined as a count of 2 or more chronic diseases. Disability is defined using limitations in activities of daily living. Results Costa Ricans have the lowest MMLE, followed by Mexicans, then individuals from the US. Individuals from the US spend about twice as long with disability-free multimorbidity compared with individuals from Costa Rica or Mexico. Females generally have longer MMLE than males, with particularly stark differences in disabling MMLE. In the US, higher education was associated with longer disability-free MMLE and shorter disabling MMLE. We identified evidence for cumulative disadvantage in Mexico and the US, where sex differences in MMLE were larger among the lower educated. Discussion Substantial sex and educational inequalities in MMLE exist within and between these countries. Estimating disability-free and disabling MMLE reveals another layer of health inequality not captured when examining disability and multimorbidity separately. MMLE is a flexible population health measure that can be used to better understand the aging process across contexts. [ABSTRACT FROM AUTHOR]

Objective: Associations have been found between five-factor model (FFM) personality traits and risk of developing specific predementia syndromes such as subjective cognitive decline (SCD) and mild cognitive impairment (MCI). The aims of this study were to: 1) Compare baseline FFM traits between participants who transitioned from healthy cognition or SCD to amnestic MCI (aMCI) versus non-amnestic MCI (naMCI); and 2) Determine the relationship between FFM traits and risk of transition between predementia cognitive states. Methods: Participants were 562 older adults from the Einstein Aging Study, 378 of which had at least one follow-up assessment. Baseline data collected included levels of FFM personality traits, anxiety and depressive symptoms, medical history, performance on a cognitive battery, and demographics. Follow-up cognitive diagnoses were also recorded. Results: Mann–Whitney U tests revealed no differences in baseline levels of FFM personality traits between participants who developed aMCI compared to those who developed naMCI. A four-state multistate Markov model revealed that higher levels of conscientiousness were protective against developing SCD while higher levels of neuroticism resulted in an increased risk of developing SCD. Further, higher levels of extraversion were protective against developing naMCI. Conclusions: FFM personality traits may be useful in improving predictions of who is at greatest risk for developing specific predementia syndromes. Information on these personality traits could enrich clinical trials by permitting trials to target individuals who are at greatest risk for developing specific forms of cognitive impairment. These results should be replicated in future studies with larger sample sizes and younger participants. [ABSTRACT FROM AUTHOR]

Objectives: To estimate the working life expectancies (WLE) of men and women with depression, examining depression by symptom trajectories from the late 20s to early 50s, and to estimate WLE by race/ethnicity and educational attainment. Methods: Data from 9206 participants collected from 1979 to 2018 in the US National Longitudinal Survey of Youth 1979 cohort were used. Depression was measured using the Center for Epidemiologic Studies Depression Scale Short Form at four time points (age 28–35, age 30–37, age 40, and age 50). Labor force status was measured monthly starting at age 30 until age 58–62. Depressive symptom trajectories were estimated using growth mixture modeling and multistate modeling estimated WLE from age 30–60 for each gender and depressive symptom trajectory. Results: Five latent symptom trajectories were established: a persistent low symptom trajectory (n = 6838), an episodic trajectory with high symptoms occurring before age 40 (n = 995), an episodic trajectory with high symptoms occurring around age 40 (n = 526), a trajectory with high symptoms occurring around age 50 (n = 570), and a persistent high symptom trajectory (n = 277). The WLE for men at age 30 was 30.3 years for the persistent low symptom trajectory, 22.8 years for the episodic before 40 trajectory, 19.6 years for the episodic around age 40 trajectory, 18.6 years for the episodic around age 50 trajectory, and 13.2 years for the persistent high symptom trajectory. Results were similar for women. WLE disparities between depression trajectories grew when stratified by race/ethnicity and education level. Conclusions: Roughly a quarter of individuals experienced episodic depressive symptoms. However, despite periods of low depressive symptoms, individuals were expected to be employed ~5–17 years less at age 30 compared to those with low symptoms. Accessible employment and mental health disability support policies and programs across the working life course may be effective in maintaining work attachment and improving WLE among those who experience depression. [ABSTRACT FROM AUTHOR]

The population‐attributable fraction (PAF) is commonly interpreted as the proportion of events that can be ascribed to a certain exposure in a certain population. Its estimation is sensitive to common forms of time‐dependent bias in the face of a time‐dependent exposure. Predominant estimation approaches based on multistate modeling fail to fully eliminate such bias and, as a result, do not permit a causal interpretation, even in the absence of confounding. While recently proposed multistate modeling approaches can successfully eliminate residual time‐dependent bias, and moreover succeed to adjust for time‐dependent confounding by means of inverse probability of censoring weighting, inadequate application, and misinterpretation prevails in the medical literature. In this paper, we therefore revisit recent work on previously proposed PAF estimands and estimators in settings with time‐dependent exposures and competing events and extend this work in several ways. First, we critically revisit the interpretation and applied terminology of these estimands. Second, we further formalize the assumptions under which a causally interpretable PAF estimand can be identified and provide analogous weighting‐based representations of the identifying functionals of other proposed estimands. This representation aims to enhance the applied statistician's understanding of different sources of bias that may arise when the aim is to obtain a valid estimate of a causally interpretable PAF. To illustrate and compare these representations, we present a real‐life application to observational data from the Ghent University Hospital ICUs to estimate the fraction of ICU deaths attributable to hospital‐acquired infections. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Inferring the timeline from mild cognitive impairment (MCI) to severe dementia is pivotal for patients, clinicians, and researchers. Literature is sparse and often contains few patients. We aim to determine the time spent in MCI, mild‐, moderate‐, severe dementia, and institutionalization until death. METHODS: Multistate modeling with Cox regression was used to obtain the sojourn time. Covariates were age at baseline, sex, amyloid status, and Alzheimer's disease (AD) or other dementia diagnosis. The sample included a register (SveDem) and memory clinics (Amsterdam Dementia Cohort and Memento). RESULTS: Using 80,543 patients, the sojourn time from clinically identified MCI to death across all patient groups ranged from 6.20 (95% confidence interval [CI]: 5.57–6.98) to 10.08 (8.94–12.18) years. DISCUSSION: Generally, sojourn time was inversely associated with older age at baseline, males, and AD diagnosis. The results provide key estimates for researchers and clinicians to estimate prognosis. [ABSTRACT FROM AUTHOR]

Abstract Objective: The progression of long-term diabetes complications has led to a decreased quality of life. Our objective was to evaluate the adverse outcomes associated with diabetes based on a patient’s clinical profile by utilizing a multistate modeling approach. Methods: This was a retrospective study of diabetes patients seen in primary care practices from 2013 to 2017. We implemented a five-state model to examine the progression of patients transitioning from one complication to having multiple complications. Our model incorporated high dimensional covariates from multisource data to investigate the possible effects of different types of factors that are associated with the progression of diabetes. Results: The cohort consisted of 10,596 patients diagnosed with diabetes and no previous complications associated with the disease. Most of the patients in our study were female, White, and had type 2 diabetes. During our study period, 5928 did not develop complications, 3323 developed microvascular complications, 1313 developed macrovascular complications, and 1129 developed both micro- and macrovascular complications. From our model, we determined that patients had a 0.1334 [0.1284, .1386] rate of developing a microvascular complication compared to 0.0508 [0.0479, .0540] rate of developing a macrovascular complication. The area deprivation index score we incorporated as a proxy for socioeconomic information indicated that patients who reside in more disadvantaged areas have a higher rate of developing a complication compared to those who reside in least disadvantaged areas. Conclusions: Our work demonstrates how a multistate modeling framework is a comprehensive approach to analyzing the progression of long-term complications associated with diabetes.

Protected areas (PAs) have been regarded as a critical strategy to protect natural forest (NF) and biodiversity. Estate‐crop expansion is an important driver of deforestation in Indonesia. Yet, little is known regarding the temporal dynamics of PA effectiveness in preventing estate‐crop expansion into NF. We employ Cox proportional hazard models and their extensions to characterize the dynamics of estate‐crop expansion into NF in Indonesia during 1996–2015. The results show that PA effectiveness in Sumatra decreased over time and became insignificant in 2012–2015. A multistate modeling analysis shows that hopping in land‐cover and land‐use change (LCLUC) trajectories with shrub and/or bare ground as intermediates has decreased PA effectiveness and facilitated the expansion. Preventing LCLUC trajectory hopping becomes crucial to biodiversity conservation because it tends to occur at lowland forest, diminishing natural habitat area and increasing NF isolation. [ABSTRACT FROM AUTHOR]

Abstract Background Prediction of the necessary capacity of beds by ward type (e.g. ICU) is essential for planning purposes during epidemics, such as the COVID− 19 pandemic. The COVID− 19 taskforce within the Ghent University hospital made use of ten-day forecasts on the required number of beds for COVID− 19 patients across different wards. Methods The planning tool combined a Poisson model for the number of newly admitted patients on each day with a multistate model for the transitions of admitted patients to the different wards, discharge or death. These models were used to simulate the required capacity of beds by ward type over the next 10 days, along with worst-case and best-case bounds. Results Overall, the models resulted in good predictions of the required number of beds across different hospital wards. Short-term predictions were especially accurate as these are less sensitive to sudden changes in number of beds on a given ward (e.g. due to referrals). Code snippets and details on the set-up are provided to guide the reader to apply the planning tool on one’s own hospital data. Conclusions We were able to achieve a fast setup of a planning tool useful within the COVID− 19 pandemic, with a fair prediction on the needed capacity by ward type. This methodology can also be applied for other epidemics.

• Thought-shape fusion suggests body dissatisfaction (BD) and preoccupation with thoughts of food (PTF) are connected. • Multi-state modeling analyzed transitions among low BD/low PTF, low BD/high PTF, high BD/low PTF, and high BD/high PTF. • Transitions to states of high BD were self-perpetuating. • Positive affect buffered against maladaptive transitions. • Negative affect, disordered eating were risk factors for maladaptive transitions. Body dissatisfaction (BD) and preoccupation with thoughts of food (PTF) are intertwined and are components of thought-shape fusion. Thought-shape fusion describes the process by which PTF lead to beliefs about weight and shape. To study thought-shape fusion in daily life and explore various transitions between BD and PTF, 30 women with binge eating completed ecological momentary assessment for 14 days. BD and PTF were assessed using continuous rating scales at each prompt. Multi-state modeling, which analyzes micro-temporal transitions between discrete states, was used to examine transitions among four states created with BD and PTF ratings. The four states included low BD/low PTF, low BD/high PTF, high BD/low PTF, and high BD/high PTF. Affect and disordered eating were examined as covariates of state transitions. Results showed high BD states were self-perpetrating, such that when in high BD states, transition to low BD states were less likely. Regarding covariates, positive affect buffered against maladaptive transitions whereas negative affect and disordered eating increased risk. Findings highlighted high BD states as influential, and negative affect and disordered eating as risk factors and positive affect as preventive. This study enhances theory of thought-shape fusion and implicates transitions from BD to PTF as possible underlying transitions. [ABSTRACT FROM AUTHOR]

Background: Prediction of the necessary capacity of beds by ward type (e.g. ICU) is essential for planning purposes during epidemics, such as the COVID- 19 pandemic. The COVID- 19 taskforce within the Ghent University hospital made use of ten-day forecasts on the required number of beds for COVID- 19 patients across different wards.Methods: The planning tool combined a Poisson model for the number of newly admitted patients on each day with a multistate model for the transitions of admitted patients to the different wards, discharge or death. These models were used to simulate the required capacity of beds by ward type over the next 10 days, along with worst-case and best-case bounds.Results: Overall, the models resulted in good predictions of the required number of beds across different hospital wards. Short-term predictions were especially accurate as these are less sensitive to sudden changes in number of beds on a given ward (e.g. due to referrals). Code snippets and details on the set-up are provided to guide the reader to apply the planning tool on one's own hospital data.Conclusions: We were able to achieve a fast setup of a planning tool useful within the COVID- 19 pandemic, with a fair prediction on the needed capacity by ward type. This methodology can also be applied for other epidemics. [ABSTRACT FROM AUTHOR]

Background: Larger, more active social networks are estimated to be associated with lower risks of cognitive decline. However, roles of various social relationships in a broad social network in protecting against cognitive decline remain to be elucidated.Objective: We aimed to investigate how social roles within a social network and number of social network members are associated with cognitive decline.Methods: Six waves of National Health and Aging Trends Study (2011-2016, NHATS) were utilized to examine the development of mild cognitive impairment (MCI) and probable dementia determined using validated criteria. Multivariable-adjusted multi-state survival models were used to model incidences and transitions, jointly with misclassification errors.Results: A total of 6,078 eligible NHATS participants were included (average age: 77.49±7.79 years; female: 58.42%; non-Hispanic white: 68.99%). Multivariable-adjusted analyses revealed that having more social network members was associated with lower hazards of conversion from MCI to probable dementia (adjusted Hazard Ratio; aHR = 0.82; 95%confidence intervals; 95%CI = [0.67-0.99]), meanwhile having at least one college-educated family member within a social network was associated with lower incidence of probable dementia (aHR = 0.37 [0.26-0.51]). Having at least one friend within a social network was associated with a lower hazard of incidence of probable dementia (aHR = 0.48 [0.33-0.71]), but a higher risk of mortality in the MCI group (aHR = 2.58 [1.47-4.51]).Conclusion: Having more social network members, having at least one friend, and having at least one college-educated family member within a social network, were associated with lower risks of incidence of dementia or conversion from MCI to dementia. [ABSTRACT FROM AUTHOR]

Background: Few studies have jointly estimated incidence of MCI, conversion to probable dementia, and mortality in a nationally representatie sample. Methods: We used data from six waves of the National Health and Aging Trends Study (2011-2016). Multivariable-adjusted multi-state survival models (MSMs) were used to model incidence upon accounting for misclassification. Results: A total of 6,078 eligible NHATS participants were included (average age: 77.49 ± 7.79 years; 58.42% females; 68.99% non-Hispanic white). The incidence of MCI was estimated to be 41.0 [35.5, 47.3]/1,000 person-years (PY). Participants converted to probable dementia at a high rate of 241.3 [189.6, 307.0]/1,000 PY, though a small number also reverted from MCI to cognitively normal. Education was associated with lower incidence of MCI and conversion to probable dementia, but increased mortality in those with MCI. There were also substantial racial and ethnic disparities in the incidence of MCI and dementia. Conclusions: Our results underscore the relatively common incidence of and conversions between MCI and dementia in community-dwelling older Americans and uncover the beneficial impact of education to withstand cognitive impairment before death. [ABSTRACT FROM AUTHOR]

Image, graphical abstract Graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) represents complete, ideal recovery after allogeneic hematopoietic cell transplantation (HCT). However, as originally proposed, this composite endpoint does not account for the possibility that HCT complications may improve after treatment. To more accurately estimate survival with response to GVHD and relapse after HCT, we developed a dynamic multistate GRFS (dGRFS) model with outcomes data from 949 patients undergoing their first allogeneic HCT for hematologic malignancy at the University of Minnesota. Because some patients were successfully treated for GVHD and relapse, dGRFS was higher than the originally defined time-to-event GRFS at 1 year (37.0 versus 27.6%) through 4 years (37.4% versus 22.2%). Mean survival without failure events was.52 years (95% confidence interval,.45 to.58 year) greater in dGRFS compared with the originally defined GRFS. Patient age (P <.001), disease risk (P <.001), conditioning intensity (P =.007), and donor type (P =.003) all significantly influenced dGRFS. The multistate model of dGRFS closely estimates the continuing and prevalent severe morbidity and mortality of allogeneic HCT. To serve the greater HCT community in more accurately modeling recovery from transplantation, we provide our R code for determination of dGRFS with annotations in Supplementary Materials. • Because some patients were successfully treated for graft-versus-host disease (GVHD) and relapse, dynamic GVHD-free, relapse-free survival (dGRFS) was approximately 10% higher than the originally defined time-to-event GRFS at 1 year (37.0% versus 27.6%). • Patient age (P <.001), disease risk (P <.001), conditioning intensity (P =.007), and donor type (P =.003) all significantly influenced dGRFS. • To serve the hematopoietic stem cell transplantation community in more accurately modeling recovery from transplantation, we provide our R code for determination of dGRFS with annotations in Supplementary Materials. [ABSTRACT FROM AUTHOR]

Individuals may reduce competition by temporally partitioning their use of a shared resource. Behavioral differences between sexes in ungulates may encourage segregation as individuals attempt to avoid antagonistic interactions. However, dominant sex and age groups may reduce subordinates' access to food resources, regardless of the subordinate's sex. We hypothesized that white-tailed deer Odocoileus virginianus temporally segregated at supplemental feeding sites based on social rank (subordinate: yearling males and adult females; dominant: adult males) and that segregation was affected by phase of the breeding season and diel cycle. If deer temporally segregate according to social rank, we predicted that the resulting activity patterns would manifest in one social class being relatively more susceptible to hunter-induced mortality. We used a multi-state modeling approach to quantify temporal segregation and calculated the probability that a feeding site was in a particular state during diurnal and nocturnal hours for each of the 3 phases of the breeding season. We determined that transition probabilities differed by season and diel cycle and dominant and subordinate social classes clearly avoided each other, with <1% co-occurrence at feeding sites. During the pre-breeding season, the probability of a subordinate being present during diurnal hours was 3.0 × more likely than a dominant being present, but did not differ during nocturnal hours. There was no difference for dominants and subordinates during diurnal or nocturnal hours during the breeding season. In the post-breeding season, subordinates were 1.7 × more likely to occur at the feeding site than a dominant during diurnal hours but they did not differ during nocturnal hours. Our results indicate that dominance status influences temporal segregation at feeding sites and is affected by the phase of the breeding season. Therefore, the resulting activity patterns may increase subordinates' risk to human predation during the pre-breeding and post-breeding seasons. [ABSTRACT FROM AUTHOR]

Introduction: Inferring the timeline from mild cognitive impairment (MCI) to severe dementia is pivotal for patients, clinicians, and researchers. Literature is sparse and often contains few patients. We aim to determine the time spent in MCI, mild-, moderate-, severe dementia, and institutionalization until death., Methods: Multistate modeling with Cox regression was used to obtain the sojourn time. Covariates were age at baseline, sex, amyloid status, and Alzheimer's disease (AD) or other dementia diagnosis. The sample included a register (SveDem) and memory clinics (Amsterdam Dementia Cohort and Memento)., Results: Using 80,543 patients, the sojourn time from clinically identified MCI to death across all patient groups ranged from 6.20 (95% confidence interval [CI]: 5.57-6.98) to 10.08 (8.94-12.18) years., Discussion: Generally, sojourn time was inversely associated with older age at baseline, males, and AD diagnosis. The results provide key estimates for researchers and clinicians to estimate prognosis., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Abstract Objectives Little is known about sex differences in healthy life expectancy among the oldest old, the fastest growing segment of the older population. This study examines sex differences in total, healthy and unhealthy life expectancy among nonagenarians. Methods Longitudinal data of 884 older adults aged 90 and over participating in the Vitality 90+ study (Tampere, Finland) were used, including 2501 observations (health or death states) from 5 measurement waves between 2001 and 2014. Using the MSM and ELECT packages in R, multistate survival models were performed to estimate the transition probabilities of older adults through the different health states and to calculate life expectancies. The analyses were done separately for two health indicators (disability and multimorbidity) to see whether patterns were consistent. Results Women had higher total life expectancies than men (about 8 months), but also higher unhealthy life expectancies. Men had a higher disability-free life expectancy between the age of 90 and 95 compared to women. For multimorbidity, no sex differences in healthy life expectancy were found. Conclusions This study showed that the male-female health-survival paradox remains at very old age. Women aged 90+ live longer than men, and spend more time in poor health. Highlights • The oldest old constitute one of the fastest growing segments of the older population • This study investigates sex differences in healthy life expectancy among nonagenarians. • The results provide evidence for the male-female health-survival paradox at very old age. • Women aged 90+ live longer than men, and spend more time in poor health. [ABSTRACT FROM AUTHOR]

Introduction: This study examines the role of educational attainment, an indicator of cognitive reserve, on transitions in later life between cognitive states (normal Mini‐Mental State Examination (MMSE), mild MMSE impairment, and severe MMSE impairment) and death. Methods: Analysis of six international longitudinal studies was performed using a coordinated approach. Multistate survival models were used to estimate the transition patterns via different cognitive states. Life expectancies were estimated. Results: Across most studies, a higher level of education was associated with a lower risk of transitioning from normal MMSE to mild MMSE impairment but was not associated with other transitions. Those with higher levels of education and socioeconomic status had longer nonimpaired life expectancies. Discussion: This study highlights the importance of education in later life and that early life experiences can delay later compromised cognitive health. This study also demonstrates the feasibility and benefit in conducting coordinated analysis across multiple studies to validate findings. Highlights: There are benefits to coordinated analysis across multiple longitudinal studies.Education and socioeconomic status delays the progression to mild cognitive impairment.Higher education and socioeconomic status increases noncognitively impaired life expectancy. [ABSTRACT FROM AUTHOR]

Objectives: To estimate and compare disability-free life expectancy (DFLE) and current age patterns of disability onset and recovery from disability between the United States and countries in Latin America and the Caribbean. Method: Disability is measured using the activities of daily living scale. Data come from longitudinal surveys of older adult populations in Costa Rica, Mexico, Puerto Rico, and the United States. Age patterns of transitions in and out of disability are modeled with a discrete-time logistic hazard model, and a microsimulation approach is used to estimate DFLE. Results: Overall life expectancy for women aged 65 is 20.11 years in Costa Rica, 19.2 years in Mexico, 20.4 years in Puerto Rico, and 20.5 years in the United States. For men, these figures are 19.0 years in Costa Rica, 18.4 years in Mexico, 18.1 years in Puerto Rico, and 18.1 years in the United States. Proportion of remaining life spent free of disability for women at age 65 is comparable between Mexico, Puerto Rico, and the United States, with Costa Rica trailing slightly. Male estimates of DFLE are similar across the four populations. Discussion: Though the older adult population of Latin America and the Caribbean lived many years exposed to poor epidemiological and public health conditions, their functional health in later life is comparable with the older adult population of the United States. [ABSTRACT FROM AUTHOR]

The invasive annual grass medusahead ( Taeniatherum caput-medusae [L.] Nevski) poses a substantial threat to the health and function of rangelands across the western United States. On rangelands containing other desirable annual grasses, selective control of medusahead is difficult as this invasive species has traits similar to those of desired species. One key trait that differs between medusahead and other annual grasses is the rate and timing of phenological development. In this study we define management states for medusahead on the basis of the patterns of variation of forage palatability and susceptibility of seed production to defoliation over phenological stages. We integrate these management states with field observations to model the rates and timing of phenology-based management states to identify when targeted grazing or mowing treatments are most appropriate using Dirichlet regression and multistate modeling. While defoliation at any phenological stage from V3 (boot) to R8 (milk stage) was effective in reducing medusahead seed head production, clipping after anthesis almost eliminated seed production. However, the observed decline in crude protein at this point (11 − 8%) suggests that the transition from R4 (emergence of awns) to R5 (anthesis) is also the point at which medusahead becomes both unpalatable and not adequately nutritious to livestock. As a consequence there was a window of 10 to 15 days when 90% or more of medusahead reproductive tillers are susceptible to grazing but could also support nutritional needs of cattle and sheep to prevent avoidance in diet selection. In contrast, the window of opportunity for mowing, on average, extended for about 35 days. In a given year, the timing in which different medusahead populations entered each phenological stage varied at both the landscape and pasture scale, which creates both challenges and opportunities in using grazing animals and other defoliation mechanisms to control medusahead. [ABSTRACT FROM AUTHOR]

Background & Aim: Multistate models are systems of multivariate survival data where individuals move through a series of istinct states following certain paths of possible transitions. Such models provide a relevant tool for studying observations of a continuous time process at arbitrary times. The aim of this study was to model the transitions from a healthy (hypertension free) state to an illness (hypertension) state of a hypertensive patient under treatment. Methods & Materials: In this article, the application of multistate modeling using hypertension data is demonstrated. Hospital data were obtained for a cohort of 353 patients from Jimma University Hospital, Ethiopia. Results: Three states of the Markov process are defined based on the WHO guideline of high blood pressure, state 1 (BP < 140/90 mmHg), state 2 (BP ≥ 140/90 mmHg) and state 3 (dropout). The first state is termed as a healthy state, the second an illness state and the third one is an absorbing state. Initially, the state transition intensities and state occupation probabilities are estimated with no covariate. Then, the effect of gender and family history of hypertension on the state transition intensities are evaluated separately and jointly using proportional intensities model. Conclusion: The study indicates that gender has a significant effect on the transition intensities but not family history ofhypertension.

Burning has traditionally been used in the southern French Alps to maintain open lands for grazing. In the context of land use abandonment, prescribed burning may be the only realistic practical tool available to oppose encroachment by woody plants in numerous mountainous landscapes. Although only recently developed as a modern tool for wildfire prevention and management of pastoral grasslands, this practice is now becoming widespread, which raises the issue of its impact on the fauna in general, and on endangered species in particular. We studied the impact of a prescribed fire on the survival and small-scale movements of one of the rarest snakes in Europe, the Orsini's viper Vipera ursinii, in order to evaluate its potential threat to population sustainability. We evaluated the body condition of snakes and the quality of their habitat, more precisely the abundance of grasshoppers as the main food resource, and the vegetation cover as shelter. About 3.6 ha of a 8.8 ha study site was burnt in autumn 2003. Snake population parameters were estimated using multi-state capture–mark–recapture methods. We demonstrate that burning reduced the survival of the vipers by more than half during the first year following the fire. Contrary to what was expected, there was no evidence of emigration from the burned to the unburned area immediately after the fire. Despite the decrease in grasshopper density and vegetation cover in the burned area, there was no evidence of mid-term mortality in snakes that could result from an increased predation rate or from the reduced body condition of snakes. As such high mortality, mainly or entirely due to the direct effect of fire, is likely to have large repercussions on population sustainability, we suggest several improvements of prescribed fire protocols to minimize their impact and strongly emphasize the need for a prescribed fire policy that takes into account specific recommendations for threatened species like Orsini's viper. The case of the Orsini's viper is very typical of conservation problems in open mountain lands, and we believe that our research will help determine the most suitable approach for long-term conservation of biodiversity in such semi-natural ecosystems. [ABSTRACT FROM AUTHOR]

Very few studies looking at slow gait speed as early marker of cognitive decline investigated the competing risk of death. The current study examines associations between slow gait speed and transitions between cognitive states and death in later life. We performed a coordinated analysis of three longitudinal studies with 9 to 25 years of follow-up. Data were used from older adults participating in H70 (Sweden; n = 441; aged ≥70 years), InCHIANTI (Italy; n = 955; aged ≥65 years), and LASA (the Netherlands; n = 2824; aged ≥55 years). Cognitive states were distinguished using the Mini-Mental State Examination. Slow gait speed was defined as the lowest sex-specific quintile at baseline. Multistate models were performed, adjusted for age, sex and education. Most effect estimates pointed in the same direction, with slow gait speed predicting forward transitions. In two cohort studies, slow gait speed predicted transitioning from mild to severe cognitive impairment (InCHIANTI: HR = 2.08, 95%CI = 1.40–3.07; LASA: HR = 1.33, 95%CI = 1.01–1.75) and transitioning from a cognitively healthy state to death (H70: HR = 3.30, 95%CI = 1.74–6.28; LASA: HR = 1.70, 95%CI = 1.30–2.21). Screening for slow gait speed may be useful for identifying older adults at risk of adverse outcomes such as cognitive decline and death. However, once in the stage of more advanced cognitive impairment, slow gait speed does not seem to predict transitioning to death anymore. • There has been an increasing interest in slow gait speed as risk factor for cognitive decline. • Very few studies have investigated the competing risk of death. • This study shows that slow gait speed predicts transitions into cognitive impairment and death. • Once in the stage of more advanced cognitive impairment, slow gait does not predict death anymore. [ABSTRACT FROM AUTHOR]

Multistate modeling methods are well-suited for analysis of some chronic diseases that move through distinct stages. The memoryless or Markov assumptions typically made, however, may be suspect for some diseases, such as hepatitis C, where there is interest in whether prognosis depends on history. This paper describes methods for multistate modeling where transition risk can depend on any property of past progression history, including time spent in the current stage and the time taken to reach the current stage. Analysis of 901 measurements of fibrosis in 401 patients following liver transplantation found decreasing risk of progression as time in the current stage increased, even when controlled for several fixed covariates. Longer time to reach the current stage did not appear associated with lower progression risk. Analysis of simulation scenarios based on the transplant study showed that greater misclassification of fibrosis produced more technical difficulties in fitting the models and poorer estimation of covariate effects than did less misclassification or error-free fibrosis measurement. The higher risk of progression when less time has been spent in the current stage could be due to varying disease activity over time, with recent progression indicating an "active" period and consequent higher risk of further progression.