Significant Linear Change Research Articles

Shear bands and interface-affected-zone enabled high strength and ductility in heterogeneous laminate-Cu

The rapid development of shear bands (SBs) in nanocrystalline Cu is prone to lead to structural failure, while coarse crystalline Cu with high strain hardening capacity can effectively inhibit the growth of SBs. Heterogeneous laminate (HL) has a structure of alternating soft and hard domains, which dramatically increases ductility while reducing strength loss. In this work, molecular dynamics (MD) simulations revealed how SBs in the HL-Cu during the stable plastic flow stage (the applied strain of 10 ∼ 20 %) strengthen the material. It is suggested that when SBs are uniformly and densely distributed in the structure, the strain gradient strengthening effect in the neighboring regions is significantly increased. Moreover, the efficiency of strain hardening can be maximized when the width of the interface-affected-zone (Defined as the region where a significant linear change in strain occurs, i.e., a strain gradient exists, located at the junction of the soft and hard domains.) caused by the uneven distribution of geometrically necessary dislocations (GNDs) is exactly the same as the layer thickness. The results show that the strength of HL can be increased by more than 14 % by reducing the layer thickness by half.

Trajectories of actigraphy-derived sleep duration, quality, and variability from childhood to adolescence: downstream effects on mental health.

We examined growth trajectories of four actigraphy-derived sleep parameters (sleep minutes, sleep efficiency, and variability in sleep minutes and efficiency across a week of assessments) across childhood and adolescence and examined individual differences in trajectories according to participants' race/ethnicity and sex. We also assessed the predictive effect of growth trajectories of sleep parameters on growth trajectories of mental health outcomes and moderation by race and sex. Youth (N = 199, 49% female, 65% white, 32% black, 3% biracial) and their parents participated in five waves of data (M ages were 9, 10, 11, 17, and 18 across waves). Participants were from a diverse range of socioeconomic backgrounds. Across participants, sleep minutes, sleep efficiency, and variability in sleep minutes and efficiency demonstrated significant linear change across childhood and adolescence. Whereas sleep duration shortened over time, sleep efficiency improved. Youth exhibited increases in night-to-night variability in sleep minutes and reductions in night-to-night variability in sleep efficiency. Highlighting the importance of individual differences, some race- and sex-related effects emerged. Black youth and male youth experienced steeper declines in their sleep duration across development relative to their respective counterparts. Black youth also demonstrated smaller improvements in sleep efficiency and greater variability in sleep efficiency compared to white youth. Finally, trajectories of sleep efficiency and variability in sleep minutes predicted trajectories of internalizing symptoms and externalizing behaviors. Findings showed significant changes in developmental trajectories of four sleep parameters across childhood and adolescence. We discuss the empirical and translational implications of the findings.

MAINTAINING BRAIN HEALTH VIA TELEHEALTH-BASED CHAIR YOGA FOR RURAL UNDERSERVED OLDER ADULTS

Abstract We conducted a randomized control pilot trial in an underserved, racially/ethnically diverse community, to examine the efficacy of (1) computer literacy training provided by high school students meeting rural older adults in their homes, followed by 2) telehealth-based online chair yoga (OCY) or computer brain games (CBG). First, high school students engaged in a “train the trainer” computer skills course using a previously-tested curriculum designed for the target population. Students mentored the older adults in learning computer skills and to access either the OCY (n = 15) or CBG (n=15), which were randomly assigned. Outcomes measured at pre, post, and three months following the 12-week intervention included computer proficiency, cognitive function, pain levels, and psychosocial well-being. In a linear mixed growth model with random intercepts, there was a significant linear trend in computer-based competency, t(50, 19) = 2.56, p = .013. Computer proficiency (computer basics, Internet and email use, communication, and calendaring) increased significantly in both the OCY and CBG groups. Importantly, there was a significant linear change in pain by group, controlling for age and living alone, F(1, 14) = 6.64, p = .022, η2 = .32 (large effect size). Chronic pain in the OCY group decreased significantly from baseline to 3-month follow-up (18.89 to 11.35) but increased in the CBG group (14.27 to 17.28). Increases in cognitive function increased pre/post t(29) = -2.98, p = .003 (one-tailed). These results are promising for older adults with limited exercise opportunities, who also face cognitive risk exacerbated by elevated pain levels.

Impairment in personality functioning throughout adolescence and co-development with personality traits, emotion regulation strategies, and psychopathology

The Alternative Model for Personality Disorders (AMPD) introduced in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), provides a dimensional operationalization of personality disorders and brings into account developmental tasks typical to adolescence, which makes it more suitable to apply to personality disorder symptomatology in adolescence. This study investigated the developmental course of impairment in personality functioning (IPF) in adolescence as well as trajectory classes and co-development with Big-Five personality traits, emotion regulation strategies, and psychopathological behaviors/symptoms. Data from a three-wave longitudinal study in 1480 high school students were used. Results revealed no significant linear change of IPF in the total sample. Four developmental trajectory classes emerged and classes significantly differed regarding psycho(patho)logical variables.

Human Capital Development Factors and Black Adolescent Tobacco and Cannabis Use.

This study examined the association of four domains of human capital development (cognitive development, social and emotional development, physical health, and mental health) and exclusive and concurrent tobacco and cannabis use (TCU) among black youth. Nationally representative annual cross-sectional data for black adolescents (12-17 years; N = 9017) in the National Survey on Drug Use and Health 2015-2019 were analyzed. Analyses examined the influence of human capital factors (cognitive development, social and emotional development, physical health, and mental health) on exclusive and concurrent TCU. In total, 50.4% were males; prevalence of 12-month tobacco use fluctuated insignificantly between 5.6% and 7.6% across survey years. Similarly, prevalence of 12-month cannabis use remained relatively stable around 13%, with no significant linear change. Prevalence of concurrent TCU also fluctuated insignificantly between 3.5% and 5.3%. Investment in cognitive development decreased the odds of tobacco (aOR = 0.58, p < .001), cannabis (aOR = 0.64, p < .001), and concurrent tobacco and cannabis (aOR = 0.58, p < .001) use. Similarly, investment in social and emotional development reduced the odds of tobacco (aOR = 086, p < .001), cannabis (aOR = 0.83, p < .001), and concurrent tobacco and cannabis (aOR = 0.81, p < .001) use. Good physical health reduced the odds of tobacco (aOR = 0.52, p < .1), cannabis (aOR = 0.63, p < .05), and concurrent TCU (aOR = 0.54, p < .05). Major depressive episodes increased the likelihood of cannabis use (aOR = 1.62, p < .001). Investment in cognitive, social, and emotional aspects of human capital development, and physical health among black youth is protective against TCU. Efforts to sustain human capital development among black adolescents may contribute to reducing TCU disparities. This is one of few studies to examine human capital development factors and their associations with TCU among black youth. Efforts to eliminate tobacco/cannabis-related disparities among black youth should also invest in social, emotional, cognitive, and physical health development opportunities.

Change Patterns During Family-Based Treatment for Pediatric Obsessive Compulsive Disorder

Cognitive behavior therapy (CBT) for young people with obsessive compulsive disorder (OCD) has recently been enhanced to target family environment factors. However, the process of change for OCD symptoms and family factors during treatment is not well understood. Uniquely, we explored patterns of change for OCD symptoms and a range of family variables throughout Baseline, Early, Mid, and Late treatment phases of family-based CBT (FCBT) for 15 young people with OCD using multiple informants. We predicted a linear reduction in OCD symptom severity and family accommodation (FA) across treatment phases, however the investigation into other family factor change patterns was exploratory. OCD symptom severity, FA, parental distress tolerance (DT), and conflict all showed significant linear change patterns across treatment phases according to multiple informants. In addition, the largest proportion of change for these variables typically occurred during the first third of treatment, highlighting the importance of identifying participants with and without early gains in future research. Blame also showed a significant linear change pattern, although with small reductions between treatment phases. Preliminary bivariate analyses sought to better understand whether family factor change predicted subsequent OCD severity change or vice versa. Similar patterns emerged across informants, including identification of OCD severity as a significant predictor of change for Blame at subsequent treatment phases. Analyses also showed bi-directional effects for DT and OCD symptoms across informants, where DT predicted OCD severity at subsequent treatment phases and vice versa. These outcomes support further research aimed at understanding the role of family factors in pediatric OCD symptom change.

Brief Adjustment Scale-6 for Measurement-Based Care: Psychometric Properties, Measurement Invariance, and Clinical Utility.

The Brief Adjustment Scale-6 (BASE-6) was recently developed for measuring general psychological functioning within measurement-based care (MBC). The present study further evaluated psychometric properties, generalizability to race/ethnic populations, and clinical utility of the BASE-6. Three adult samples, Sample 1: online community participants (n = 394); Sample 2: college students (n = 249); Sample 3: outpatient clinic clients (n = 80), were included. The results demonstrated a high level of internal consistency, good test-retest reliability, and convergent validity in all samples. The unidimensional structure of BASE-6 was confirmed and factorial invariance was established across groups. Finally, the BASE-6 captured change over time by demonstrating a large effect size of pre-post treatment changes and significant linear change in multilevel growth modeling. These results support the BASE-6 as a reliable and valid measure regardless of race/ethnicity and can sensitively detect clinical change over the course of the treatment. Thus, the BASE-6 appears to accurately monitor overall psychological adjustment.

Effect of a Multi-Ingredient Supplement Designed to Regulate Mood on Physiological and Psychological Outcomes: A Randomized, Double-Blind, Placebo-Controlled Trial

Stress is inevitable in college, and many students utilize alternatives to professional help such as supplements to manage stress, anxiety, or depression. A randomized, double-blind, placebo-controlled trial was conducted to assess the effectiveness of a multi-ingredient supplement (MIS) in supporting optimal mood balance and reducing daily stress among healthy collegiate-aged students (clinicaltrials.gov, NCT05109923). Participants (age 18-22) were randomly assigned to a placebo (PLA; n = 29) or MIS (n = 27) group and were asked to consume 2 capsules upon waking and before bed. Resting heart rate, blood pressure and salivary cortisol awakening response (CAR) were measured at weeks 2, 5 and 8. Depression, anxiety, stress, and affect were assessed weekly. There was a significant negative linear change in CAR, depression, stress, positive and negative affect throughout the study although only CAR differed by group. From week 2 to 5, MIS decreased, on average, from 0.22 μg/dL to 0.14 μg/dL (-0.8 μg/dL), whereas PLA, on average, increased from 0.11 μg/dL to 0.17 μg/dL. MIS continued to experience a decline in CAR, ending the study with an average CAR of 0.08 μg/dL. These results suggest that MIS may help maintain a healthy physiological response during stressful life events.

A latent trajectory analysis of inpatient depression treatment.

Patients seeking psychotherapy may progress through treatment in varying ways. Modeling multiple treatment trajectories through growth mixture modeling provides a comprehensive way of understanding a patient population. Multiple trajectories may additionally help researchers describe complexities within a patient population, such as those with severe and persistent disorders and comorbid symptoms, to understand characteristics of patients that may be struggling during treatment. We analyzed the depression symptom outcome measures (PHQ-9) for 246 patients receiving inpatient depression treatment. We constructed a growth mixture model of depression symptom changes, allowing the number of treatment trajectories to emerge through the data, and utilized goodness-of-fit indices to select the superior model. Results indicated three classes was the best fitting model, with patients either (a) patients started above the clinical cutoff score for depression and had significant linear change over time, ending therapy just above the clinical cutoff-"Improvement-leveling off-improvement"; (b) patients started therapy well above the clinical cutoff, showed symptom alleviation at the beginning of therapy before the trajectory started to level off-"High symptom pressure"; or (c) patients started therapy just below the clinical cutoff, had steady change throughout therapy, ending well below the clinical cutoff-"continuous improvement." Implications of the study may include altering the length of treatment based on patient presenting symptoms in order to best serve patients and utilize hospital resources. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Mindfulness Practice with a Brain-Sensing Device Improved Cognitive Functioning of Elementary School Children: An Exploratory Pilot Study.

This is the first pilot study with children that has assessed the effects of a brain–computer interface-assisted mindfulness program on neural mechanisms and associated cognitive performance. The participants were 31 children aged 9–10 years who were randomly assigned to either an eight-session mindfulness training with EEG-feedback or a passive control group. Mindfulness-related brain activity was measured during the training, while cognitive tests and resting-state brain activity were measured pre- and post-test. The within-group measurement of calm/focused brain states and mind-wandering revealed a significant linear change. Significant positive changes were detected in children’s inhibition, information processing, and resting-state brain activity (alpha, theta) compared to the control group. Elevated baseline alpha activity was associated with less reactivity in reaction time on a cognitive test. Our exploratory findings show some preliminary support for a potential executive function-enhancing effect of mindfulness supplemented with EEG-feedback, which may have some important implications for children’s self-regulated learning and academic achievement.

The Tree Drawing Test in Evolution: An Explorative Longitudinal Study in Alzheimer's Disease.

To study the evolution of the Tree Drawing Test (TDT) in a group of Alzheimer's disease (AD) patients. A total of 33 AD patients were consecutively evaluated by Mini Mental State Evaluation (MMSE) and TDT. The evolution of the TDT parameters, trunk-to-crown (TC) and space occupation (SO) index, were analyzed. The median age at first visit was 79years. Globally, trees drawn by patients showed an evolution characterized by a progressive reduction of the crown compared to the trunk. TC index showed a significant linear growth change (2.52 points per year) while SO index did not significantly increase. No significant associations were found examining the relations between MMSE and TC and SO index. TDT could represent a complementary technique to the main neuropsychological screening tests for orienting cognitive impairment diagnosis and an aid in following the evolution of cognitive impairment over time in AD patients.

Meteorological Drought Events and Their Evolution from 1960 to 2015 Using the Daily SWAP Index in Chongqing, China

Meteorological droughts are natural disasters that have been linked to economic losses and casualties. Decision-makers need to understand the temporal and spatial variation of meteorological drought events at a daily to weekly scale to develop a more elaborate framework for drought risk management. The present study used the standardized weighted average of precipitation index (SWAP) as an indicator of meteorological droughts, computed from the daily precipitation dataset (1960–2015) of 34 meteorological stations in Chongqing, China. The multi-threshold run theory was applied to identify drought events. Variation of drought characteristics was estimated by the modified Sen’s trend test. The results suggested the following findings: (1) the onset, duration, and severity of drought events identified by the SWAP index are in good agreement with the real local records; (2) there was no significant linear trend and abrupt change in annual duration and severity of drought events, but the decadal variation was obvious. From a decadal perspective, the annual frequency, duration, and severity of drought events showed a steady decreasing trend before the 1990s, and then fluctuated upward; (3) the spatial variation of the duration and severity of ordinary drought events was quite inconsistent at different periods. The annual drought days and severity increased from 1960 to 2015 but decreased after 1990. From 1960 to 2015, the duration days and severity of persistent, long persistent, severe, and extreme drought events declined insignificantly in most parts of the middle and southeast regions but increased in the western and northeast regions. The drought situation in Chongqing shows a large range of variation and obvious spatial heterogeneity. The SWAP index is an effective tool to identify the evolution of daily scale meteorological drought events.

Systematic search for long-term transit duration changes in Kepler transiting planets

ABSTRACT Holczer, Mazeh, and collaborators (HM+16) used the Kepler 4-yr observations to derive a transit-timing catalog, identifying 260 Kepler objects of interest (KOI) with significant transit timing variations (TTV). For KOIs with high enough S/Ns, HM+16 also derived the duration and depth of their transits. In this work, we use the duration measurements of HM+16 to systematically study the duration changes of 561 KOIs and identify 15 KOIs with a significant long-term linear change of transit durations and another 16 KOIs with an intermediate significance. We show that the observed linear trend is probably caused by a precession of the orbital plane of the transiting planet, induced in most cases by another planet. The leading term of the precession rate depends on the mass and relative inclination of the perturber, and the period ratio between the two orbits, but not on the mass and period of the transiting planet itself. Interestingly, our findings indicate that, as a sample, the detected time derivatives of the durations get larger as a function of the planetary orbital period, probably because short-period planetary systems display small relative inclinations. The results might indicate that short-period planets reside in relatively flattened planetary systems, suggesting these systems experienced stronger dissipation either when formed or when migrated to short orbits. This should be used as a possible clue for the formation of such systems.

Factors associated with increases over time in the quality of Active Support in supported accommodation services for people with intellectual disabilities: A multi-level model

BackgroundDisability support organisations have embraced Active Support, but it has proved difficult to embed in services. AimsThis study aimed to identify the factors associated with increases over time in the quality of Active Support. MethodData were collected on the predicted variable of the quality of Active Support, and predictor variables of service user, staff and service characteristics, including practice leadership, and composition and size of services from 51 services in 8 organisations over 2–7 time points. Data were analysed using multi-level modelling. ResultsThere was significant linear change in Active Support scores (group mean centered at the organisational level) over time. Individuals with lower support needs received better Active Support and those with higher support needs experienced greater increases over time. Stronger practice leadership and more staff with training in Active Support were significant predictors of the quality of Active Support. Larger services with seven or more individuals and where there was a very heterogeneous mix of individuals were associated with lower quality of support. ConclusionsEnsuring strong practice leadership, and staff training in Active Support that emphasises the principle of adapting support to each individual’s level of ability and preferences are key to delivering high levels of Active Support.

Trends in the use of cigarettes, cigars, and marijuana among students with and without asthma, 2003–2017

Aim: Asthma has symptoms that can be exacerbated by using combustible products such as tobacco and marijuana. This study assessed the prevalence and trends in current use of cigarettes, cigars, and marijuana among U.S. high school students with and without asthma. Methods: The national Youth Risk Behavior Survey (YRBS) is a biennial, school-based, nationally representative survey of U.S. students in grades 9–12. Trends during 2003–2017 in current (past 30-day) use of cigarettes, cigars, and marijuana among students with and without asthma were examined using logistic regression. Asthma was defined as reporting that a doctor or nurse ever told the student they had asthma. T-tests were used to compare cigarette, cigar, and marijuana use by asthma status and year, frequency of use, and student characteristics. Results: During 2003–2017, both current cigarette and cigar smoking decreased (p < 0.05) with rates that were similar among students with and without asthma. There was no significant linear change in current marijuana use, irrespective of asthma status. During most years, cigarette, cigar, and marijuana use were more common among students with asthma than without. In 2017, the most frequent use of cigarettes, cigars, and marijuana was among those with asthma than without. Differences in cigarette, cigar, and marijuana use by asthma status were apparent by demographic subgroups. Conclusions: Given the adverse respiratory effects of tobacco and marijuana smoking, efforts to educate all youth about the dangers of using these substances is critical, particularly among those with asthma.

The Association of Maternal Perceived Stress With Changes in Their Children's Healthy Eating Index (HEI-2010) Scores Over Time.

Few studies have examined the role of maternal stress in relation to their children's dietary quality and its trajectory over time. The objective of this longitudinal study was to examine the effect of baseline maternal stress on the change in their 8- to 12-year-old children's dietary quality over 1 year. Mother-child dyads (N = 189) from the greater Los Angeles area participating in the Mothers' and their Children's Health (MATCH) study in 2014-2016 completed assessments at baseline, 6 months, and 12 months. At baseline, mothers (mean age = 41.0 years, standard deviation [SD] = 6.1) completed the 10-item Cohen's Perceived Stress Scale (PSS). At each time point, children (51% female, mean age = 9.6 years, SD = 0.9) completed up to two 24-hr dietary recalls. Dietary data were used to calculate each child's Healthy Eating Index 2010 (HEI-2010) score at each time point. Multilevel models examined the effect of time on the patterns of change in children's HEI-2010 scores over 1 year and the cross-level interaction between baseline maternal PSS score and time on the change in children's HEI-2010 scores. On average, there was no significant linear change in child HEI-2010 across 1 year (b = -0.410, p = .586). Controlling for covariates, the rate of change in HEI-2010 differed depending on mother's baseline PSS (i.e., significant cross-level interaction effect) (b = -0.235, p = .035). Our results showed that higher-than-average maternal stress at baseline was associated with greater decline in children's dietary quality over 1 year. Family-based dietary interventions that incorporate maternal stress reduction could have positive effects on children's dietary quality.

Examining Patterns of Change in the Acquired Capability for Suicide Among Eating Disorder Patients

Several models of suicidal behavior posit that, to transition from suicidal ideation to attempting suicide, individuals must have an acquired capability for suicide (ACS), comprised of fearlessness about death (FAD) and pain tolerance. ACS is hypothesized to increase monotonically through exposure to painful and provocative experiences. However, recent research suggests that ACS can decrease, bringing into question the hypothesis of monotonic increase. This study examined the nature of change in ACS over time within a sample of patients with eating disorder (ED). We predicted that there would be two classes of change in ACS: one high and increasing and one moderate and stable. One hundred female patients with ED reported on ACS at admission and weekly during treatment. Growth mixture modeling to test models of FAD and pain tolerance identified that, for both factors, a one-class intercept-only model was the best-fitting model, suggesting that patients entered treatment with midlevel ACS and experienced no significant linear change over the course of treatment. Acquired capability for suicide demonstrated stability in this study; results highlight the need for additional research examining ACS across different timescales and in varied populations.

The nonlinear variation of drought and its relation to atmospheric circulation in Shandong Province, East China.

Considerable attention has recently been devoted to the linear trend of drought at the decadal to inter-decadal time scale; however, the nonlinear variation of drought at multi-decadal scales and its relation to atmospheric circulation need to be further studied. The linear and nonlinear variations of the Palmer drought severity index (PDSI) in Shandong from 1900 to 2012 and its relations to the Pacific decadal oscillation (PDO), El Niño-Southern Oscillation (ENSO), Siberian high (SH) and Southern Oscillation (SO) phase changes from multi-scale are detected using linear regression, the Mann–Kendall test, ensemble empirical mode decomposition (EEMD) and the Pearson correlation analysis method. The results indicate that the PDSI shows no statistically significant linear change trend from 1900 to 2012; however, before (after) the late 1950s, PDSI shows a significant upward (downward) trend (P < 0.01) with a linear rate of 0.28/decade (−0.48/decade). From 1900 to 2012, the PDSI also exhibits a nonlinear variation trend at the inter-annual scale (quasi-3 and quasi-7-year), inter-decadal scale (quasi-14-year) and multi-decadal scale (quasi-46 and quasi-65-year). The variance contribution rate of components from the inter-annual scale is the largest, reaching 38.7%, and that from the inter-decadal scale and multi-decadal scale are 18.9% and 19.0%, respectively, indicating that the inter-annual change exerts a huge influence on the overall PDSI change. The results also imply that the effect of the four atmospheric circulations (PDO, ENSO, SH, SO) on PDSI at the multi-decadal variability scale are more important than that at the other scales. Consequently, we state that PDSI variation at the inter-annual scale has more instability, while that at the inter-decadal and multi-decadal scale is more strongly influenced by natural factors.

Men With Late Effects of Polio Decline More Than Women in Lower Limb Muscle Strength: A 4-Year Longitudinal Study

BackgroundIn persons with prior paralytic poliomyelitis, progressive muscle weakness can occur after a stable period of at least 15 years. Knowledge is limited about which factors influence changes in lower limb muscle strength in these persons. ObjectiveTo assess changes in lower limb muscle strength annually over 4 years in persons with late effects of polio and to identify prognostic factors for changes in muscle strength. DesignA prospective, longitudinal study. SettingUniversity hospital outpatient program. ParticipantsFifty-two ambulant persons (mean age ± standard deviation: 64 ± 6 years) with verified late effects of polio. MethodsMixed linear models were used to analyze changes in muscle strength and to identify determinants among the following covariates: gender, age, age at acute polio infection, time with late effects of polio, body mass index, and estimated baseline muscle weakness. Main Outcome MeasurementsKnee extensor and flexor and ankle dorsiflexor muscle strength were measured annually with a Biodex dynamometer. ResultsThe men (n = 28) had significant linear change over time for all knee muscle strength measurements, from −1.4% (P < .05) per year for isokinetic knee flexion in the less-affected lower limb to −4.2% (P < .001) for isokinetic knee extension in the more-affected lower limb, and for 2 ankle dorsiflexor muscle strength measurements (−3.3%-1.4% per year [P < .05]). The women (n = 24) had a significant linear change over time only for ankle dorsiflexor measurements (4.0%-5.5% per year [P < .01]). Gender was the strongest factor that predicted a change in muscle strength over time. ConclusionsOver 4 years, men had a greater decline in muscle strength than did women, but the rate of decline did not accelerate. This finding indicates that gender could be a contributing factor to the progressive decline in muscle strength in persons with late effects of polio.

Trends of Venous Thromboembolism (VTE) and Risk Factors for Developing VTE in Pediatric Patients Undergoing Hematopoietic Stem Cell Transplant (HSCT) in children’s Hospitals-a PHIS Database Study

Background: The incidence of venous thromboembolism (VTE) is rising in critically ill children. It is one of the most common hospital acquired complications and the use of thromboprophylaxis remains controversial. Exposure to risk factors including central venous lines, infection/inflammation and prolonged immobilization increases the risk of VTE while underlying coagulopathy, thrombocytopenia, requirement of invasive procedures, organ failure or medications increase the risk of bleeding. Therefore, understanding these risk factors in various subsets of critically ill children is vital to develop VTE prevention strategies. Since Hematopoietic Stem Cell Transplant (HSCT) recipients comprise a subset of patients at high risk of developing VTE due to exposure to the risk factors above, we explored the trends and risk factors for VTE in children undergoing HSCT using a national administrative database during the past decade.Methods: ThePediatric Health Information System (PHIS) database was queried using the ICD-9-CM codes to identify children <=18 years old who underwent HSCT at 40 hospitals from 2004-2013. A step-wise search strategy was developed to identify the subset of patients whose billing codes indicate that they had developed at least one incidence of VTE after discharge or during their HSCT admission. The patient level data (age, gender, ethnicity, pre-HSCT diagnosis) and HSCT related data [Graft versus host disease (GVHD), Veno-occlusive disease (VOD), Cytomegalovirus infection (CMV) and length of stay) was abstracted from the HSCT encounter. Descriptive analyses were performed to compare means, and percentages between VTE and various risk factors. Chi Square and Fisher exact test were used as appropriate. We performed a linear regression analysis to compare the trends of VTE over the last 10 years.Results: A total of 8559 children underwent HSCT from 2004 to 2013. Of these, 450 (5.26%) developed VTE after HSCT discharge. The details of patient characteristics are shown in Table 1. The VTE incidence and 95% confidence intervals by year are shown in figure 1. There was no significant linear change in the trends of VTE in the patients undergoing an HSCT over the last 10 years, (p=0.296), Figure 1. In bivariate analyses, patients who developed VTE were older, had more hematological malignancies, longer length of hospitalization during the encounter and had higher incidence of acute GVHD (aGVHD), chronic GVHD (cGVHD) and VOD (p<0.001).Conclusions: This study showed that despite concerns about rising incidence of VTE in critically ill hospitalized children, the incidence of VTE as defined by the billing codes in the HSCT population has remained stable during the last decade.We have also described that age, prolonged hospitalization and hematological malignancy were associated with occurrence of VTE in this group of patients. The higher incidence of aGVHD, VOD and cGVHD in patients imply that ongoing inflammation predisposes to prothrombotic milieu. These findings warrant consideration prior to implementing VTE prophylaxis in HSCT patients. More prospective studies are needed to explore the utility of primary thromboprophylaxis in this population. Table 1CharacteristicPatients with thrombosisN=450Patients without thrombosisN=8109p-valueAge (years)MeanSt. Deviation9.2 5.98 5.3<0.0001 GenderMaleFemale249 (55%) 201 (45%)4717 (58%) 3392 (42%)0.235EthnicityHispanicNon-hispanicUnknown79 (18%) 221 (49%) 150 (33%)1546 (19%) 3593 (44%) 2970 (37%)0.136DiagnosisAplastic anemiaHematological malignancy(including MDS)NHLBrain tumorSCIDSickle Cell DiseaseThalassemiaOthers24 (5%) 158 (35%) 19 (4%) 23 (5%) 11 (2%) 7 (2%) 0 (0%) 208 (46%)498 (6%) 2412 (30%) 213 (3%) 554 (7%) 166 (2%) 131 (2%) 2 (0.02%) 4133 (51%)0.485 0.017 0.042 0.156 0.564 0.921 0.739Length of stay (days)MeanSt. Deviation59 51.9144 34.06<0.0001Acute GVHD75 (17%)729 (9%)<0.0001Chronic GVHD73 (16%)521 (6%)<0.0001VOD14 (3%)124 (2%)0.009CMV Viremia15 (3%)236 (3%)0.604 [Display omitted] DisclosuresNo relevant conflicts of interest to declare.