Significant Bidirectional Associations Research Articles

Bi-directional association between outdoor or social activities and cognitive function: do the PM2.5 exposure catalyze the detrimental inactivity-poor cognition cycle?

BackgroundPrevious research has shown that lack of leisure activities, either outdoor or social activities, impedes cognitive function. However, the interrelationship between poor cognition and deficient activities is understudied. In addition, whether exposure to air pollution, such as PM2.5, can accelerate the detrimental ‘inactivity-poor cognition’ cycle, is worthy of investigation. MethodsWe used data from the 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). We assessed the frequency of outdoor or social activities at each wave. The cognitive function was examined using a China-Modified Mini-mental State Examination. We estimated the residential exposure to fine particular matter (PM2.5) via a satellite-based model. We applied cross-lagged panel (CLP) model to examine the bi-directional relationship between outdoor or social activities and cognitive function. We then examined the effect of PM2.5 exposure with sequent cognitive function and activities using generalized estimation equation (GEE) model. FindingsOverall, we observed significant bi-directional associations between outdoor or social activities and cognitive function. Participants with better cognitive function in the last wave were more likely to engage in outdoor or social activities in the following wave (outdoor activities: β = 0.37, 95% CI [0.27,0.48], P < 0.01; social activities: β = 0.05, 95% CI [0.02,0.09] P < 0.01). Meanwhile, higher engagement in outdoor or social activities in the last wave was associated with more favorable cognitive function in the following wave (outdoor activities: β = 0.06, 95% CI [0.03,0.09], P < 0.01; social activities: β = 0.10, 95% CI [0.03,0.18], P < 0.01). Notably, an increase in PM2.5 exposure during the preceding year was significantly associated with a declining cognitive function (β = −0.05, 95% CI [−0.08,−0.03], P < 0.01), outdoor activities (β = −0.02, 95% CI [−0.04, −0.01], P < 0.01) and social activities (β = −0.02, 95% CI [−0.02, −0.01], P < 0.01) in the current year; the lagged effects of the PM2.5 exposure in the past year of the last wave on activities and cognitive function of the following wave were also observed. InterpretationOur findings not only indicate the bi-directional links between the frequency of outdoor or social activities and cognitive function, but also report that PM2.5 exposure plays a role in catalyzing the detrimental inactivity-poor cognition cycle. Future research should investigate whether the policy-driven interventions, such as clean air policies, can break the unfavorable activity-cognition cycle, and thereby promoting health from the dual gains in leisure activities and cognition.

The interplay of depression symptoms and physical activity: Bidirectional insights from 25-years of the Americans' changing lives panel

BackgroundDepression symptomology (DSx) and insufficient Physical Activity (PA) are among the leading causes of illness, and major contributors to global public health burden. Reviews and meta-analyses indicate that DSx and PA cause each other, yet most studies conducted use data and analyses which cannot specify their bidirectional associations across the life course. MethodThe present study estimates dynamic panel models with fixed effects through structural equation models with full-information maximum likelihood estimation (ML-SEM) based on 5 waves (1986–2011) of the Americans' Changing Lives (ACL) panel. This is a nationally representative probability sample of 3499 non-institutionalized U.S. adults ages 25 and older in 1986. Respondents participated in an average of 3.29 waves, with 67.84% participating in at least 3 waves, and 27.26% participating in all 5 waves. Models adjust for age, partner status, social integration, activity limitations, and serious financial problems. Data are available from the ICPSR (4690). ResultsEstimates from ML-SEM reveal negative and significant bidirectional cross-sectional associations between DSx and PA. Models also indicate a negative and significant cross-lagged association from DSx to PA, but not from cross-lagged PA to DSx. On both sides, earlier levels are significantly associated with future levels of PA and DSx. ConclusionsThis study is the first to use a causal inference technique which adjusts for all time-invariant confounders while modelling the bidirectional linkages between depression symptoms and physical activity over 25-years of adulthood. It supports literature showing a consistent cross-sectional relationship, and advances understanding on how DSx earlier in the adult life course may influence PA as people age.

Exploration of the biomarkers of comorbidity of psoriasis with inflammatory bowel disease and their association with immune infiltration.

There was evidence that significant bidirectional associations between psoriasis and inflammatory bowel diseases (IBDs), which influences management strategy of the patients, so the investigation on the mechanisms by which these two diseases co-occur is important. The Gene Expression Omnibus (GEO) database was used to download gene expression profiles of psoriasis and IBD. The differentially expressed genes (DEGs) between disease and health control groups for each data set were calculated, and Venn diagram was used to obtain for intersection. We performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the intersection, followed by developing a protein-protein interaction network and module construction, and identified hub genes by cytoHubba. Thereafter, least absolute shrinkage and selection operator algorithms was used to identify the co-biomarkers of psoriasis and IBD from the top 50 hub genes. The biomarkers were used to construct a screening model, the discriminatory capacity of which was verified by receiver operating characteristic (ROC) curves. CIBERSORT algorithm was utilized to estimate the compositional patterns of immune cell infiltration in biomarkers of psoriasis and IBD. Spearman rank correlation analysis was used to further evaluate the correlation between the identified biomarkers and immune cells. A total of 271 shared DEGs were screened. The GO and KEGG enrichment analysis indicated that the shared DEGs were mainly enriched in response to lipopolysaccharide, secretory granule lumen, cytokine activity, and interleukin (IL)-17 signaling pathway. Fifty genes such as IL1B, IL6, were identified as hub genes, based on which, FOS, IFI44, MMP9, MNDA, PTGS2, S100A9, and STAT1 were identified as biomarkers of psoriasis. CCL20, CD274, CTGF, CXCL1, CXCL10, CXCL2, CXCL9, FCGR3B, FOS, GBP1, GZMB, IFI27, IFI6, IL1RN, ISG15, ISG20, LCN2, LILRB2, MMP12, MMP7, S100A8, TLR8, and TNFSF13B were identified as biomarkers of IBD. FOS was the common biomarker of psoriasis and IBD. Screening models were validated in the validation data set (Psoriasis: area under the curve (AUC)=1.000, IBD: AUC=0.870). Immunocyte infiltration analysis showed the macrophages cells, mast cells resting, and T cells CD4 memory activated have the common characteristics in psoriasis and IBD. FOS may play a key role in the occurrence and development of psoriasis complicated with IBD and macrophages cells may be an entrance for treating this comorbidity.

Revealing associations between spatial time series trends of COVID-19 incidence and human mobility: an analysis of bidirectionality and spatiotemporal heterogeneity

BackgroundUsing human mobility as a proxy for social interaction, previous studies revealed bidirectional associations between COVID-19 incidence and human mobility. For example, while an increase in COVID-19 cases may affect mobility to decrease due to lockdowns or fear, conversely, an increase in mobility can potentially amplify social interactions, thereby contributing to an upsurge in COVID-19 cases. Nevertheless, these bidirectional relationships exhibit variations in their nature, evolve over time, and lack generalizability across different geographical contexts. Consequently, a systematic approach is required to detect functional, spatial, and temporal variations within the intricate relationship between disease incidence and mobility.MethodsWe introduce a spatial time series workflow to investigate the bidirectional associations between human mobility and disease incidence, examining how these associations differ across geographic space and throughout different waves of a pandemic. By utilizing daily COVID-19 cases and mobility flows at the county level during three pandemic waves in the US, we conduct bidirectional Granger causality tests for each county and wave. Furthermore, we employ dynamic time warping to quantify the similarity between the trends of disease incidence and mobility, enabling us to map the spatial distribution of trends that are either similar or dissimilar.ResultsOur analysis reveals significant bidirectional associations between COVID-19 incidence and mobility, and we develop a typology to explain the variations in these associations across waves and counties. Overall, COVID-19 incidence exerts a greater influence on mobility than vice versa, but the correlation between the two variables exhibits a stronger connection during the initial wave and weakens over time. Additionally, the relationship between COVID-19 incidence and mobility undergoes changes in direction and significance for certain counties across different waves. These shifts can be attributed to alterations in disease control measures and the presence of evolving confounding factors that differ both spatially and temporally.ConclusionsThis study provides insights into the spatial and temporal dynamics of the relationship between COVID-19 incidence and human mobility across different waves. Understanding these variations is crucial for informing the development of more targeted and effective healthcare policies and interventions, particularly at the city or county level where such policies must be implemented. Although we study the association between mobility and COVID-19 incidence, our workflow can be applied to investigate the associations between the time series trends of various infectious diseases and relevant contributing factors, which play a role in disease transmission.

Longitudinal relations between theory of mind and academic achievement among deaf and hard-of-hearing school-aged children

This 2-year longitudinal study investigated the bidirectional relations between the development of theory of mind (ToM) and academic competences in a sample of 270 deaf and hard-of-hearing (DHH) children (Mage at Wave 1 = 7.52 years, SD = 0.99; 58.5% boys and 41.5% girls). Across three waves (10 months apart), children were assessed for their ToM abilities, using the ToM scale and a second-order false belief task, as well as for their language and mathematics skills. Cross-lagged correlational analysis revealed significant bidirectional associations between ToM and academic achievement (language and mathematics). That is, ToM predicted academic achievement with similar strength as ToM development itself was predicted by academic achievement. Our results highlight the bidirectional nature of the association between ToM and academic achievement, and they show that ToM development plays a crucial role in DHH children’s school functioning.

Bidirectional and dynamic relationships between social isolation and frailty among older adults in China

ObjectiveThis study aimed to investigate the bidirectional and dynamic relationships between Social Isolation (SI) and frailty among older adults in China. MethodsUsing data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), this study utilized a Generalized Cross-Lagged Model (GCLM) to examine the temporal interrelationships between SI and frailty among individuals aged 65 years and older. ResultsThe findings revealed significant bidirectional associations between SI and frailty among older adults in China. The GCLM identified strong temporal dynamics in the relationships between SI and frailty, with both effects increasing and showing a "cumulative disadvantage" effect as older adults aged. ConclusionThis study underscores the significance of tailored interventions aimed at mitigating both SI and frailty among older adults in China, thus addressing the bidirectional impact. The findings emphasize the necessity for early intervention strategies to counteract the cumulative disadvantages associated with SI and frailty in later-life outcomes.

A longitudinal model of sleep problems and classroom self-regulation across elementary school

This study explored longitudinal and bidirectional associations among behavioral sleep problems and self-regulation difficulties across the elementary school years. Analyses drew data from the Kindergarten Cohort (N = 4983) of the Longitudinal Study of Australian Children (LSAC) across five data waves, when children were aged 4–13 years (49% female, 86% English-speaking). Cross-lagged structural equation models revealed significant bidirectional associations, with greater sleep problems consistently predicting classroom self-regulation two years later, while poorer self-regulation predicted later sleep problems only at certain time points. Greater behavioral sleep problems were associated with poorer post-elementary achievement and social-emotional wellbeing, while stronger classroom self-regulation skills supported more positive outcomes in these constructs. Findings indicate strong developmental associations among sleep problems and dysregulation.

Bidirectional association between handgrip strength and ADLs disability: a prospective cohort study.

Decreased handgrip strength (HGS) and activities of daily living (ADL) disability are common in aging populations. No studies have evaluated the bidirectional associations between HGS and ADL disability. This study aimed to explore the bidirectional effects of HGS and ADL disability. This study analyzed data from two waves (2011 and 2015) of China Health and Retirement Longitudinal Study (CHARLS). Low HGS is defined by the Asian Working Group for Sarcopenia criteria. Meanwhile, disability was assessed by ADLs scale. The prospective bidirectional association between HGS and ADL disability was examined using binary logistic regression. Subgroup analysis were performed according to age and gender. A total of 4,902 and 5,243 participants were included in the Stage I and Stage II analyses, respectively. On the one hand, low HGS was significantly associated with subsequent ADL disability. The odds ratio (OR) value of developing BADL disability and IADL disability were 1.60 (95% confidence interval (CI): 1.23-2.08) and 1.40 (95% CI: 1.15-1.70), respectively, in participants with low HGS. On the other hand, baseline ADL disability was associated with an increased risk of developing low HGS. The OR value of developing low HGS were 1.84 (95% CI: 1.34-2.51) and 1.46 (95% CI: 1.19-1.79) for participants with BADL disability and participants with IADL disability, respectively. Lastly, the strength of the bidirectional associations varied among subgroups. A significant bidirectional associations were identified between HGS and ADL disability. Interventions should be developed to prevent the development or progression of both low HGS and ADL disability.

Examining the Bidirectional Nature of Loneliness and Anxiety Among Older Adults in Daily Life.

Loneliness in later life increases the risk for adverse health outcomes; however, less is known about how loneliness is maintained. Anxiety may play an important role in maintaining loneliness, but little is known about how this connection plays out over time in daily life. This study thus focused on the within-person associations between momentary loneliness and anxiety among older adults. Participants were 317 diverse older adults (40% Black; 13% Hispanic, mean age = 77.45 years, 67% women) systematically recruited from the Bronx, NY, who completed ecological momentary assessments 5 times daily for 14 consecutive days. Multilevel models tested bidirectional contemporaneous, momentary cross-lagged (t - 1), day-level cross-lagged (average day to end of day), and day-to-day cross-lagged associations between loneliness and anxiety. Separate sensitivity analyses controlled for concurrent overall mood valence or depressed state. Gender and mild cognitive impairment (MCI) status were tested as moderators at all timescales. Significant bidirectional associations between loneliness and anxiety were found at the contemporaneous and momentary cross-lagged (t - 1) timescales. Higher average daily loneliness predicted higher end-of-day anxiety, but not vice versa. Loneliness and anxiety were not significantly associated from day to day. Sensitivity analyses revealed some associations varied depending on inclusion of either concurrent mood valence or depressed state. Neither gender nor MCI status moderated associations at any timescale. Findings shed light on the complex temporal ordering of loneliness and anxiety in daily life and extend contemporary theoretical notions of loneliness, including the possibility of interventions that target key moments in daily life.

Bidirectional Mendelian Randomization Study of Personality Traits Reveals a Positive Feedback Loop Between Neuroticism and Back Pain

We conducted a bidirectional Mendelian randomization study to examine the causal effects of six personality traits (anxiety, neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness) on back pain associated with health care use and the causal effect of back pain on the same risk factors. Genetic instruments for the personality traits and back pain were obtained from the largest published genome-wide association studies conducted in individuals of European ancestry. We used inverse weighted variance meta-analysis and Causal Analysis Using Summary Effect for primary analyses and sensitivity analyses to examine evidence for causal associations. We interpreted exposure-outcome associations as being consistent with a causal relationship if results of at least one primary analysis were statistically significant after accounting for multiple statistical testing (P-value < .0042), and the direction and magnitude of effect estimates were concordant between primary and sensitivity analyses. We found evidence for statistically significant bidirectional causal associations between neuroticism and back pain, with odds ratio 1.51 (95% confidence interval 1.37; 1.67) of back pain per neuroticism sum score standard deviation, P-value = 7.80e-16; and beta = .12, se = .04 of neuroticism sum score standard deviation per log odds of back pain, P-value = 2.48e-03. Other relationships did not meet our predefined criteria for causal association. PerspectiveThe significant positive feedback loop between neuroticism and back pain highlights the importance of considering neuroticism in the management of patients with back pain.

Bidirectional associations between psoriasis and migraine: A systematic review and meta-analysis.

To evaluate the association between psoriasis and migraine. MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for relevant observational studies from their respective inception to May 1, 2022. A random-effects model meta-analysis was performed to calculate the risk estimates quantifying the associations between psoriasis and migraine. We also performed a sensitivity analysis by including only studies with adjusted risk estimates and a subgroup analysis according to the severity of psoriasis. We included 9 studies with 6,742,075 participants. The meta-analysis illustrated increased odds for prevalent migraine among patients with psoriasis (pooled OR: 1.69, 95% CI: 1.26-2.28) and increased odds for prevalent psoriasis among those with migraine (OR: 1.88, 95% CI: 1.32-3.67). A subgroup analysis of cohort studies demonstrated an increasingly higher risk of incident migraine in patients with mild psoriasis and severe psoriasis (IRR being 1.37 (95% CI 1.30-1.44) and 1.55 (95% CI 1.29-1.86), respectively). This meta-analysis revealed significant bidirectional associations between migraine and psoriasis. Greater severity of psoriasis appears to be associated with a higher risk of developing migraine. Clinicians should evaluate symptoms of migraine in patients with psoriasis and provide proper treatments.

Depressive symptoms and falls among Chinese older adults: A bidirectional relationship.

Falls and depressive symptoms are prevalent and costly. Although they are frequently interrelated, the nature of interrelationships between them was not well understood. Therefore, using longitudinal data, we aimed to explore whether there is a longitudinal bidirectional relationship between falls and depressive symptoms among older Chinese and whether this is different for men and women. Older adults aged 60 years+ who completed all 2011, 2013, 2015 waves of data from the China Health and Retirement Longitudinal Study on falls and depressive symptoms were included (N=2,203). Random intercept multilevel models were used to analyze data. Significant bidirectional associations at between-person (b=0.09, SE=0.01, p<0.001) and within-person levels (b=0.05, SE=0.02, p=0.005) were observed between depressive symptoms and falls. When participants reported falls, they reported higher levels of depressive symptoms. However, no gender differs in these relationships. Regardless of gender, there are significant bidirectional associations between falls and depressive symptoms.

It goes both ways: The relationship between anxiety and mild cognitive impairment.

To investigate the relationship between anxiety and mild cognitive impairment (MCI), and whether it is mediated by perceived stress, at the population level. In a longitudinal study of 368 adults aged 65+ from a population-based cohort, we annually assessed anxiety symptoms (GAD-7), perceived stress (PSS-4), and ratings on the Clinical Dementia Rating (CDR®), where CDR=0.5 was operationalized as MCI. Examining data from three consecutive assessment waves, we first determined the associations between anxiety at the first wave with MCI at the third wave, and vice versa. We then used mediation analyses to determine whether the pathways in both directions were mediated by perceived stress at the second wave, adjusting for demographics and other relevant covariates. We confirmed significant bidirectional longitudinal associations between anxiety and MCI. Perceived stress was detected as a significant mediator for both pathways between anxiety and MCI, explaining 37.1% of the total effect of anxiety on incident MCI while conversely explaining 27.1% of the total effect of MCI on anxiety. A bidirectional relationship with a two-year lag between anxiety and MCI was mediated through perceived stress. Clinicians should be sensitive both to potential consequent anxiety when patients present with cognitive impairment, and to potential incipient MCI when the presenting complaint is anxiety. Managing stress may help mitigate adverse outcomes. This article is protected by copyright. All rights reserved.

LONGITUDINAL ASSOCIATIONS BETWEEN FALLS AND DEPRESSIVE SYMPTOMS AMONG CHINESE OLDER ADULTS

Abstract Falls and depressive symptoms are prevalent and costly to Chinese older adults. Although falls and depressive symptoms are frequently interrelated, previous studies were mainly based on cross-sectional data, and the nature of interrelationships between them were not well understood. In this study, we aimed to examine the longitudinal bidirectional relationship between falls and depressive symptoms among Chinese older adults, and whether this bidirectional relationship is different for males and females, given that females are found to suffer from falls and depressive symptoms significantly more than males. Older adults aged 60 years+ who completed all three waves of data from the China Health and Retirement Longitudinal Study on falls and depressive symptoms between 2011 (wave 1), 2013 (wave 2), and 2015 (wave 3) were included in the current analysis (Nf2,203). Data were analyzed using random intercept multilevel models that adjusted for demographic information (e.g., age, education, and marital status). Overall, there is a relatively stable rates of comorbid falls and depression (about 10%) over time among Chinese older adults. Significant bidirectional associations at between-person and within-person levels were observed between depressive symptoms and falls over time, with greater depressive symptoms associated with higher risk for falls and vice versa. However, such associations were not different between males and females. Taken together, these findings indicate the importance of addressing both depression and falls at the same time to prevent falls in the clinical practice for both males and females.

Bidirectional Associations between Daytime Napping Duration and Metabolic Syndrome: A Nationally Representative Cohort Study.

We aimed to examine the bidirectional associations between daytime napping duration and metabolic syndrome (MetS). Using data from the China Health and Retirement Longitudinal Study from 2011 to 2015, modified Poisson regression models were performed to explore the longitudinal associations of baseline napping duration with the occurrence and remission of MetS. Generalized estimating equation was conducted to explore the association between baseline MetS status with subsequent changes in daytime napping duration. Cross-lagged panel analysis was performed to further verify their bidirectional relationships. During the four-year follow-up, among 5041 participants without MetS at baseline, extended naps were significantly associated with MetS occurrence, compared with non-napping. This association was only significant in individuals with adequate night-time sleep duration or good sleep quality of the 2898 participants with MetS at baseline. Excessive napping duration may be not favorable for MetS remission especially for adequate night-time sleepers. With respect to reverse associations, baseline MetS status significantly increased the napping duration during the subsequent follow-up period. Finally, there were significant bidirectional cross-lagged associations between napping duration and MetS severity score after adjusting for all covariates. Our study indicates bidirectional relationships exist between daytime napping duration and MetS. Interestingly, longer napping duration was detrimental to cardiometabolic health only in those with sufficient night-time sleep duration or good sleep quality.

The association between and development of school enjoyment and general knowledge.

Learning environments can support the development of foundational knowledge and promote children's attitudes toward learning and school. This study explores the relation between school enjoyment and general knowledge from preschool (2016-2017) to kindergarten (2017-2018) in 1359 children (Mage = 55, 61 months, female=50%; 58.5% Hispanic, 17% Black, 10% Asian, 10% White, 5% multiracial/other; linguistically diverse). Cross-lagged panel models showed significant bidirectional associations between preschool enjoyment and change in general knowledge from preschool to kindergarten with a standardized coefficient of β= .21 (p< .001) and associations between preschool general knowledge and change in enjoyment, β= .09 (p= .015). Exploratory analyses with teacher characteristics and demographic subgroup comparisons are discussed. These associations suggest the potential intervention strategy of promoting early school enjoyment to support broader academic development.

Testing Bidirectional, Longitudinal Associations Between Disturbed Sleep and Depressive Symptoms in Children and Adolescents Using Cross-Lagged Models

Understanding the longitudinal, bidirectional associations between disturbed sleep and depression in childhood and adolescence is crucial for the development of prevention and intervention programs. To test for bidirectional associations and cascade processes between disturbed sleep and depressive symptoms covering both childhood and adolescence and to test for the moderating processes of sex and pubertal status in adolescence. A prospective cohort study using the Québec Longitudinal Study of Child Development (QLSCD; 1997-ongoing). QLSCD's objective is to identify early childhood factors associated with long-term psychosocial and academic adjustment. Data were collected across 8 waves between ages 5 years (2003) and 17 years (2015). Associations were tested through cross-lagged models in childhood (5, 7, and 8 years), and in adolescence (10, 12, 13, 15, and 17 years). Data were analyzed from February to October 2021. Primary outcomes were disturbed sleep and depressive symptoms. Disturbed sleep was parent-reported and included sleep duration, time awake in bed, daytime sleepiness, sleep talking, sleepwalking, night terrors, and nightmares. Depressive symptoms were parent-reported in childhood (Child Behavior Checklist and Revised Ontario Child Health Study Scales), and self-reported in adolescence (Mental Health and Social Inadaptation Assessment for Adolescents). Data on 1689 children (852 female [50.4%]) and 1113 adolescents (595 female [53.5%]) were included in the analyses. In childhood, significant bidirectional associations between depressive symptoms and disturbed sleep at all time points were found, indicating cascade processes (range β = 0.07; 95% CI, 0.02-012 to β = 0.15; 95% CI, 0.10-0.19). In adolescence, significant bidirectional associations from depressive symptoms to disturbed sleep (β = 0.09; 95% CI, 0.04-0.14) and vice versa (β = 0.10; 95% CI, 0.04-0.16) between 10 and 12 years were found. Between 12 and 13 years, depressive symptoms were modestly associated with disturbed sleep (β = 0.05; 95% CI, 0.001-0.10) but the reverse association was not significant. Cross-lagged estimates were nonsignificant after 13 years. The associations did not vary as a function of either sex or puberty-by-sex. These findings suggest that disturbed sleep is associated with the consolidation of depressive symptoms starting in childhood, which, in turn, is associated with ongoing sleep problems. It is possible that timely and appropriate interventions for incipient disturbed sleep and depression prevent spiraling effects on both domains.

Cross-Lag Model of Medical Responsibility and Skills in Youth With Spina Bifida.

This study examined bidirectional associations between mother- and father-reported medical responsibility and medical skill mastery in youth with spina bifida (SB). Participants were 140 youth with SB and their parents who participated in three waves of a longitudinal study across four years (ages 8-15 years at Time 1). Mother- and father-report of both medical responsibility and medical skill mastery were used, and age and estimated intelligence quotient were included as covariates, in cross-lagged models. The cross-lagged model provided evidence for significant bidirectional associations between mother-reported medical responsibility and skill mastery across time (root mean square error of approximation=0.09, comparative fix index=0.97). These paths showed that higher levels of child responsibility predicted an increase in skill mastery and that higher levels of mastery predicted an increase in child responsibility across time. Moreover, based on mother-report, sharing of responsibility had stronger effects on increases in skill mastery (Time 1 to Time 2 β=.25, Time 2 to Time 3 β=.27) than skill mastery had on increases in child responsibility (Time 1 to Time 2 β=.08, Time 2 to Time 3 β=.07). The only significant cross-lagged path for father-report was from Time 1 skill mastery to Time 2 responsibility (β=.34). Mothers perceive a bidirectional relationship between responsibility and skill mastery across time, whereas fathers appear to mainly consider how skills might affect a subsequent increase in responsibility sharing. Thus, it is important to consider both parents' perspectives when working to increase medical autonomy in youth with SB.

Bidirectional and Dynamic Relationships Between Social Isolation and Physical Functioning Among Older Adults: A Cross-Lagged Panel Model of US National Survey Data.

Previous studies examining unidirectional relationships between social isolation and physical functioning among older adults may be biased due to reverse causality. This study leveraged data from a US national sample of older adults and a novel estimation method to identify bidirectional associations between these 2 phenomena and their associated temporal dynamics. The analyses were based on 9 waves of panel data from a sample of adults aged 65 and older from the US National Health and Aging Trends Study (n = 12 427 individuals) and a cross-lagged panel model. Social isolation was measured using the Social Isolation Index (SII) and physical functioning through the Short Physical Performance Battery (SPPB). One SD increase in the SPPB was associated with a -0.013 SD decrease (95% confidence interval [CI]: -0.023 to -0.004) in the SII a year later, whereas 1 SD increase in the SII was associated with a larger -0.058 SD decrease (95% CI: -0.069 to -0.046) in the SPPB a year later. The SII→SPPB effect lasted for approximately 5 years, whereas the SPPB→SII lasted for approximately 3 years. This study confirmed the existence of statistically significant bidirectional associations between social isolation and physical functioning among older adults in the United States, net of reverse causation. Because the effect of social isolation dominates, the findings indicate that public health strategies to promote successful aging should prioritize interventions that enrich older adults' social networks. Furthermore, the effect time horizons yielded by the model point to the optimal timing for the re-delivery of interventions.

Impaired recovery is associated with increased injury and illness: A retrospective study of 536 female netball athletes.

Sport science and medicine practitioners are interested in the relationships between training load, injury, and illness. The extent to which training preparedness is associated with workload-related injury and illness risk is debated. Therefore, this study applied multi-level mixed effect logistic regression to investigate time-dependent (±7- and ±28-day) relationships between training preparedness (fatigue, mood, motivation, soreness, stress, sleep duration, and quality), training load, injury, and illness in 536 elite and pre-elite female netball athletes. Absolute risk (AR±95% CI) of sustaining an injury (0.98±0.06%, n=1122 injuries, N=254 athletes) or illness (1.09±0.10%, n=2881, N=432 athletes) was calculated. All training preparedness variables combined resulted in an absolute risk of 0.88%-5.88% and 0.87%-20% for injury and illness, respectively. Injury and illness had significant (P<.05) bidirectional (ie, both increased and decreased) associations with physical (soreness) and physiological (sleep duration and quality), while illness also had negative (mood, motivation) and positive (stress) associations with psychological training preparedness variables. Low sleep duration in the 48-h period prior was associated (P=.005) with increased injury risk (OR=0.91±0.03; AR=4.00%), while "very poor" sleep quality (OR=0.59±0.02; AR=7.83%) or extremes of too little (<5 hours, OR=1.01±0.03; AR=3.13%-14.29%) and too much (>10 hours, OR=1.01±0.03; AR=2.61%-10.98%) sleep had bidirectional associations (P<.001) with an increased illness risk. Changes in training preparedness variables demonstrated bidirectional associations with injury and illness. These outcomes suggest that sport science and medicine practitioners should monitor sleep, physical, and psychological recovery status, to aid early detection and intervention regarding injury and illness symptomology.