Tutorial on directed acyclic graphs

Building a better model: abandon kitchen sink regression

This paper critically examines 'kitchen sink regression', a practice characterised by the manual or automated selection of variables for a multivariable regression model based on p values or model-based information criteria. We highlight the pitfalls of this method, using examples from perinatal/neonatal medicine, and propose more robust alternatives. The concept of directed acyclic graphs (DAGs) is introduced as a tool for describing and analysing causal relationships. We highlight five key issues with 'kitchen sink regression': (1) the disregard for the directionality of variable relationships, (2) the lack of a meaningful causal interpretation of effect estimates from these models, (3) the inflated alpha error rate due to multiple testing, (4) the risk of overfitting and model instability and (5) the disregard for content expertise in model building. We advocate for the use of DAGs to guide variable selection for models that aim to examine associations between a putative risk factor and an outcome and emphasise the need for a more thoughtful and informed use of regression models in medical research.

Outdoor Air Pollution Relates to Amygdala Subregion Volume and Apportionment in Early Adolescents

Background

Outdoor air pollution is associated with an increased risk for psychopathology. Although the neural mechanisms remain unclear, air pollutants may impact mental health by altering limbic brain regions, such as the amygdala. Here, we examine the association between ambient air pollution exposure and amygdala subregion volumes in 9-10-year-olds.

Methods

Cross-sectional Adolescent Brain Cognitive Development SM (ABCD) Study ® data from 4,473 participants (55.4% male) were leveraged. Air pollution was estimated for each participant's primary residential address. Using the probabilistic CIT168 atlas, we quantified total amygdala and 9 distinct subregion volumes from T1- and T2-weighted images. First, we examined how criteria pollutants (i.e., fine particulate matter [PM 2.5 ], nitrogen dioxide, ground-level ozone) and 15 PM 2.5 components related with total amygdala volumes using linear mixed-effect (LME) regression. Next, partial least squares correlation (PLSC) analyses were implemented to identify relationships between co-exposure to criteria pollutants as well as PM 2.5 components and amygdala subregion volumes. We also conducted complementary analyses to assess subregion apportionment using amygdala relative volume fractions (RVFs).

Results

No significant associations were detected between pollutants and total amygdala volumes. Using PLSC, one latent dimension (LD) (52% variance explained) captured a positive association between calcium and several basolateral subregions. LDs were also identified for amygdala RVFs (ranging from 30% to 82% variance explained), with PM 2.5 and component co-exposure associated with increases in lateral, but decreases in medial and central, RVFs.

Conclusions

Fine particulate and its components are linked with distinct amygdala differences, potentially playing a role in risk for adolescent mental health problems.

Identifying the risk factors associated with food insecurity in the UK veteran population: a nationwide survey

There has been limited focus placed on exploring food insecurity within the UK-ex-Armed Forces population. The present study aims to build on initial work by investigating the prevalence and associated factors of food insecurity within UK veterans and their families and their current health status. 881 veterans (or a family member) who previously served in the Royal Navy and Royal Marines, Army and the Royal Air Force completed an online survey to explore health status, food insecurity and receipt of benefits. In total, 16.9% of survey respondents were part of food-insecure households, with 12% of these also experiencing some element of hunger. Working age, non-officer rank at the time of service discharge, not being married, living in rented accommodation, having at least one medical condition and in receipt of other benefits were significant risk factors associated with food insecurity. Understanding the specific risk factors associated with food insecurity is vital to develop personalised interventions and policies, such as income support programmes and affordable housing initiatives. However, more work is needed to further explore the factors associated with food insecurity, particularly in the long term.

Is Kinesiophobia Associated With Quality of Life, Level of Physical Activity, and Function in Older Adults With Knee Osteoarthritis?

BACKGROUND

Beyond knee pain itself, the fear of movement, also known as kinesiophobia, recently has been proposed as a potential factor contributing to disability and functional limitation in patients with knee osteoarthritis (OA). Nevertheless, the available evidence on the association of kinesiophobia with patient-reported outcome measures (PROMs) in knee OA remains limited.

QUESTIONS/PURPOSES

Among patients with nonoperatively treated knee OA, we asked: (1) Is kinesiophobia associated with decreased quality of life (QoL), functional outcomes, and physical activity? (2) What are the patient disease and psychosocial demographic factors associated with kinesiophobia?

METHODS

This was a multicenter, cross-sectional study of 406 general orthopaedic patients from two urban, referral-based tertiary hospitals in Singapore under a single healthcare group who received nonoperative treatment for knee OA. Between July 2020 and January 2022, a total of 1541 patients were treated for knee OA nonoperatively. Based on that, 60% (923) of patients were rejected due to refusal to participate in the study, 3% (52) of patients were enrolled but did not show up for their appointments for data collection, and a further 10% (160) had incomplete data sets, leaving 26% (406) for this study's analysis. The mean age of patients was 64 ± 8 years, 69% were women, and 81% were Chinese. The level of kinesiophobia in patients was measured using the Brief Fear of Movement scale, a validated 6-item questionnaire ranging from a score of 6 to 24 to measure kinesiophobia in OA, with higher scores representing higher levels of kinesiophobia. In terms of PROMs, the QoL and functional level of patients were measured using the QoL and activities of daily living (ADL) components of the widely validated 12-item Knee Injury and Osteoarthritis Outcome Score (KOOS-12). The KOOS-12 is a questionnaire consisting of 12 items encompassing three domains (QoL, ADL, and pain), with each item ranging from 0 to 4 and higher scores representing worse outcomes. The University of California, Los Angeles (UCLA) Activity Scale was used to measure the level of physical activity in patients. The UCLA score is a descriptive 10-level activity scale ranging from a score of 1 to 10, with higher scores representing greater physical activity levels. A directed acyclic graph, which is a relationship map used to depict and visualize the confounders between the studied variables, was used to identify the confounders between kinesiophobia and PROMs (QoL, function, and physical activity). An ordinal regression model was used to explore: (1) the association between kinesiophobia (as measured using the Brief Fear of Movement scale) and PROMs (as measured using KOOS QoL, KOOS ADL, and the UCLA Activity Scale), adjusting for key confounders such as age, gender, pain, side of arthritis, OA duration/severity, and psychosocial factors (for example, depression, anxiety, and education levels), and (2) the association between kinesiophobia (Brief Fear of Movement scale) and various patient disease and psychosocial demographic factors.

RESULTS

After accounting for confounders, greater kinesiophobia (higher Brief Fear of Movement scores) was associated with lower QoL (KOOS QoL score adjusted IQR OR 0.69 [95% confidence interval (CI) 0.53 to 0.90]; p = 0.007) and lower physical activity (UCLA score adjusted IQR OR 0.68 [95% CI 0.52 to 0.90]; p = 0.007); however, there was no association between kinesiophobia and function (KOOS ADL score adjusted IQR OR 0.90 [95% CI 0.70 to 1.17]; p = 0.45). After adjusting for age, gender, OA duration, pain, and BMI, higher levels of anxiety (Patient Health Questionnaire 2 [PHQ-2] anxiety score adjusted OR 2.49 [95% CI 1.36 to 4.58]; p = 0.003) and depression (PHQ-2 depression score adjusted OR 3.38 [95% CI 1.73 to 6.62]; p < 0.001) were associated with higher levels of kinesiophobia. Education level, OA disease severity, side of arthritis (unilateral versus bilateral), and history of previous injury or surgery on the knee were not associated with kinesiophobia.

CONCLUSION

Clinicians should assess for kinesiophobia and other psychological comorbidities such as depression and anxiety at the point of initial evaluation and subsequent follow-up of knee OA with simple validated tools like the Brief Fear of Movement scale (kinesiophobia) in the clinic. This allows for clinicians to identify high-risk individuals and offer evidence-based treatment such as cognitive behavioral therapies with a multidisciplinary team, including a physical therapist and psychologist, to manage these psychological comorbidities and improve outcomes in patients with knee OA. While kinesiophobia was found to be associated with poorer QoL and physical activity, future studies including larger observational cohort studies should be conducted to determine causal and prognostic relationships between kinesiophobia and outcomes in knee OA.

LEVEL OF EVIDENCE

Level III, prognostic study.

Preventable sources of bias in subgroup analyses and secondary outcomes of randomized trials

BACKGROUND

Randomized controlled trials are the gold standard for determining treatment efficacy in medicine. To deter harmful practices such as p-hacking and hypothesizing after the results are known, any analysis of subgroups and secondary outcomes must be documented and pre-specified. However, they can still introduce bias (and routinely do) if they are not treated with the same consideration as the primary analysis.

METHODS

We describe several sources of bias that affect subgroup and secondary outcome analyses using published randomized trials and causal directed acyclic graphs (DAGs).

RESULTS

We use the RECOVERY and START trials to elucidate sources of bias in analyses of subgroups and secondary outcomes. Chance imbalance can occur if the distribution of prognostic variables is not sought for any given subgroup analysis as for the main analysis. This differential distribution of prognostic variables can also occur in analyses of secondary outcomes. Selection bias can occur if the subgroup variable is causally related to staying in the trial. Given loss to follow up is not normally addressed in subgroups, attrition bias can pass unnoticed in these cases. In every case, the solution is to take the same considerations for these analyses as we do for primary analyses.

CONCLUSIONS

Approval of treatments and clinical decisions can occur based on results from subgroup or secondary outcome analyses. Thus, it is important to give them the same treatment as primary analyses to avoid preventable biases.

Life course social mobility, race and tooth loss in adulthood: The role of dental health services

OBJECTIVES

To evaluate the extent to which dental care factors in adulthood modify and, at the same time, mediate the association between race/ethnicity and social mobility from childhood to adulthood with two oral health outcomes in adults.

METHODS

In 2012, 1222 individuals 20-59 years old participated in the second wave of the Epi-Floripa Study in Florianopolis, Brazil. Exposures included social mobility based on adulthood and childhood events, dental care in previous years, type of dental care coverage, reason for dental visits and race. The number of missing and decayed teeth were dichotomised as MT >0 and DT >0.

RESULTS

The prevalence of missing and decayed teeth was 61.9% and 23.0%, respectively. Age-sex adjusted inequalities in decayed and missing teeth among Black and White individuals were 41.2 percentage points (pp) (95% CI: 3.9-78.7) and 53.1 pp (19.5:86.7), respectively. Inequalities between those persistently higher and lower in socioeconomic position were 42.6 pp (14.6-70.7) and 90.0 pp (62.1-100). The Relative Excess of Risk due to Interaction (RERI) was not statistically significant (p < 0.05). Oaxaca-Blinder decomposition analyses showed that dental care variables accounted for a small proportion of inequalities.

CONCLUSIONS

This result implies that dental care is unlikely to significantly reduce or increase oral health inequalities in this particular population.

The Impact of Gardening on Dietary Inflammation: Mixed-Effect Models and Propensity Score Analyses

Introduction

Gardening has been found to increase vegetable intake and reduce BMI; this suggests that it may improve diets by lowering inflammatory content. The goal of this study goal was to evaluate the effect of gardening on Dietary Inflammatory Index scores.

Methods

Longitudinal data were collected annually between 2015 and 2018 from adults in low-income, urban neighborhoods of Cleveland and Columbus, Ohio. The authors measured the association between gardening and Dietary Inflammatory Index in the full data set using multivariable mixed-effect models with a random intercept for participant (Model 1; n=409). To further explore potential causation, the author used propensity score analyses in a subset of the data by building a 1-to-1 matched model (Model 2; n=339).

Results

Of 409 adults, 30.3% were gardeners with Dietary Inflammatory Index scores ranging from -6.228 to +6.225. Participating in gardening was associated with lower Dietary Inflammatory Index scores in the mixed-effects model (-0.45; 95% CI= -0.85, -0.04; Model 1) and the 1-to-1 matched model (-0.77; 95% CI= -1.40, -0.14; Model 2).

Conclusions

The analyses indicate that gardeners had lower Dietary Inflammatory Index scores than nongardeners, implying lower diet-driven inflammation. These findings highlight the potential for a causal relationship between gardening and Dietary Inflammatory Index, which should be confirmed in future studies. If this relationship is validated, strategies to increase gardening may be worth testing as primary prevention tools for diet-driven chronic disease.

Association Between In-hospital Mortality and the Institutional Factors of Intensive Care Units with a Focus on the Intensivist-to-bed Ratio: A Retrospective Cohort Study

Purpose: To elucidate the relationship between in-hospital mortality and the institutional factors of intensive care units (ICUs), with a focus on the intensivist-to-bed ratio. Methods: A retrospective cohort study was conducted using a Japanese ICU database, including adult patients admitted between April 1, 2020 and March 31, 2021. We used a multilevel logistic regression model to investigate the associations between in-hospital mortality and the following institutional factors: the intensivist-to-bed ratios on weekdays or over weekends/holidays, different work shifts, hospital-to-ICU-bed ratio, annual-ICU-admission-to-bed ratio, type of hospital, and the presence of other medical staff. Results: The study population comprised 46 503 patients admitted to 65 ICUs. The in-hospital mortality rate was 8.1%. The median numbers of ICU beds and intensivists were 12 (interquartile range [IQR] 8-14) and 4 (IQR 2-9), respectively. In-hospital mortality decreased significantly as the intensivist-to-bed ratio at 10 am on weekdays increased: the average contrast indicated a 20% (95% confidence interval [CI]: 1%-38%) reduction when the ratio increased from 0 to 0.5, and a 38% (95% CI: 9%-67%) reduction when the ratio increased from 0 to 1. The other institutional factors did not present a significant effect. Conclusions: The intensivist-to-bed ratio at 10 am on weekdays had a significant effect on in-hospital mortality. Further investigation is needed to understand the processes leading to improved outcomes.

Antiseizure Medications and Cardiovascular Events in Older People With Epilepsy

Importance

How epilepsy may promote cardiovascular disease remains poorly understood.

Objective

To estimate the odds of new-onset cardiovascular events (CVEs) over 6 years in older people with vs without epilepsy, exploring how enzyme-inducing antiseizure medications (EIASMs) and traditional cardiovascular risk factors mediate these odds.

Design, Setting, and Participants

This was a prospective cohort study using the comprehensive cohort of the Canadian Longitudinal Study on Aging (CLSA), with 6 years of follow-up (2015-2021, analysis performed in December 2023). The CLSA is an ongoing, national study of 51 338 adults aged 45 to 85 years at baseline who are recruited in Canada. The comprehensive cohort includes 30 097 individuals living near 1 of 11 data collection centers. Participation in the CLSA was voluntary; participation rate was 45%. Among those in the comprehensive cohort, individuals reporting no previous history of CVEs (ie, stroke, transient ischemic attack [TIA], or myocardial infarction [MI]) at baseline were excluded. No other exclusion criteria were applied. A total of 86% of participants completed follow-up.

Exposure

Lifetime history of epilepsy.

Main Outcomes and Measures

The primary outcome was new-onset CVEs over 6 years. Secondary outcomes were new-onset strokes, TIAs, and MIs. Logistic models were fitted for these outcomes as a function of epilepsy, age, sex, household income, and education level. Mediation analyses were conducted for strong EIASM use, weak EIASM use, Framingham score, Physical Activity Scale for the Elderly (PASE) score, and waist to hip ratio.

Results

Among the 30 097 individuals in the comprehensive cohort, a total of 27 230 individuals (mean [SD] age, 62.3 [10.1] years; 14 268 female [52.4%]) were included, 431 with a lifetime history of epilepsy. New-onset CVEs were more likely in epilepsy, with an adjusted odds ratio of 2.20 (95% CI, 1.48-3.27). The proportion of the effect of epilepsy on new-onset CVEs was mediated as follows by each of the following variables: strong EIASM use, 24.6% (95% CI, 6.5%-54.6%), weak EIASM use, 4.0% (95% CI, 0.8%-11.0%), Framingham score, 1.4% (95% CI, -1.6% to 4.5%), PASE score, 3.3% (95% CI, 1.4%-6.8%), and waist to hip ratio, 1.6% (95% CI, 0.4%-3.7%).

Conclusions and Relevance

Results of this cohort study reveal that epilepsy was associated with new-onset CVEs. Nearly one-third of this association can be explained by EIASMs. These findings should be considered when choosing an antiseizure medication for a person at risk for cardiovascular disease.

How to develop causal directed acyclic graphs for observational health research: a scoping review

Causal directed acyclic graphs (DAGs) serve as intuitive tools to visually represent causal relationships between variables. While they find widespread use in guiding study design, data collection and statistical analysis, their adoption remains relatively rare in the domain of psychology. In this paper we describe the relevance of DAGs for health psychology, review guidelines for developing causal DAGs, and offer recommendations for their development. A scoping review searching for papers and resources describing guidelines for DAG development was conducted. Information extracted from the eligible papers and resources (n = 11) was categorised, and results were used to formulate recommendations. Most records focused on DAG development for data analysis, with similar steps outlined. However, we found notable variations on how to implement confounding variables (i.e., sequential inclusion versus exclusion). Also, how domain knowledge should be integrated in the development process was scarcely addressed. Only one paper described how to perform a literature search for DAG development. Key recommendations for causal DAG development are provided and discussed using an illustrative example.

The association of dietary total antioxidant capacity and gestational diabetes: a prospective cohort study from the Mothers and their children's health (MATCH)

BACKGROUND/OBJECTIVES

There is evidence to support the hypothesis that a diet rich in antioxidants can help safeguard against the development of gestational diabetes mellitus (GDM). This study aimed to investigate the association between dietary total antioxidant capacity (DTAC) during early pregnancy and the risk of GDM.

SUBJECTS/METHODS

We included 1856 pregnant women in their first trimester from the Mothers and their Children's Health (MATCH) prospective cohort study. Prepregnancy dietary intake was assessed using a validated food frequency questionnaire (FFQ) and was used to calculate the DTAC score. Incident GDM was diagnosed based on the American Diabetes Association criteria. We estimated the association between DTAC and GDM using propensity score-based inverse probability weighting (IPW).

RESULTS

Overall, 369 (14.6%) of the pregnant women were identified with GDM. The mean DTAC score and the corresponding standard deviation (SD) was 2.82± (2.56) mmol/100 g, with a range of 0.01 to 18.55. The adjusted risk of GDM decreased by 34% (95% CI = 10%, 52%, p = 0.023) for each DTAC score increase. The results showed that women in the highest quartile of DTAC had a lower risk of developing GDM compared to those in the lowest quartile (adjusted RR: 0.29, 95% CI: 0.12, 0.68, p = 0.005).

CONCLUSION

DTAC in early pregnancy is significantly associated with a lower risk of GDM. Additional larger cohort studies are needed to validate these findings.

The association between physical activity and delayed neurocognitive recovery in elderly patients: a mediation analysis of pro-inflammatory cytokines

BACKGROUND

Delayed neurocognitive recovery (dNCR) can result in unfavorable outcomes in elderly surgical patients. Physical activity (PA) has been shown to improve cognitive function, potentially by reducing systemic inflammatory responses. However, there is a lack of supportive data indicating whether PA has a protective effect against dNCR.

AIMS

To examine the correlation between dNCR and PA, and to further analyze if pro-inflammatory cytokines mediate this relationship.

METHODS

This study is a prospective nested case-control investigation of elderly patients who had knee replacement surgery. dNCR was defined as a decline in cognitive function compared with baseline by using a battery of neuropsychological tests. PA was assessed with the Physical Activity Scale for the Elderly (PASE). Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum concentrations of IL-6, IL-1β, and TNF-α. Multivariable logistic regression analysis was conducted to assess the association between PA and dNCR. Mediation analysis was employed to evaluate whether pro-inflammatory cytokines mediate the relationship between them.

RESULTS

A cohort of 152 patients was included, resulting in an incidence rate of dNCR of 23.68%. PA was associated with dNCR after full adjustment [OR = 0.199, (95% CI, 0.061; 0.649), P = 0.007]. Mediation analysis showed that the IL-6 mediated the statistical association between PA and dNCR, with mediation proportions (%) of 77.68 (postoperative concentration of IL-6) or 27.58 (the absolute change in IL-6 before and after surgery).

CONCLUSIONS

PA serves as a protective factor against dNCR, possibly through the reduction of pro-inflammatory cytokine concentrations. THE CHINESE CLINICAL TRAIL REGISTRY: : www.http://chictr.org.cn , Registration No. ChiCTR2300070834, Registration date: April 24, 2023.

Mycobacterium tuberculosis cough aerosol culture status associates with host characteristics and inflammatory profiles

Interrupting transmission events is critical to tuberculosis control. Cough-generated aerosol cultures predict tuberculosis transmission better than microbiological or clinical markers. We hypothesize that highly infectious individuals with pulmonary tuberculosis (positive for cough aerosol cultures) have elevated inflammatory markers and unique transcriptional profiles compared to less infectious individuals. We performed a prospective, longitudinal study using cough aerosol sampling system. We enrolled 142 participants with treatment-naïve pulmonary tuberculosis in Kenya and assessed the association of clinical, microbiologic, and immunologic characteristics with Mycobacterium tuberculosis aerosolization and transmission in 129 household members. Contacts of the forty-three aerosol culture-positive participants (30%) are more likely to have a positive interferon-gamma release assay (85% vs 53%, P = 0.006) and higher median IFNγ level (P < 0.001, 4.28 IU/ml (1.77-5.91) vs. 0.71 (0.01-3.56)) compared to aerosol culture-negative individuals. We find that higher bacillary burden, younger age, larger mean upper arm circumference, and host inflammatory profiles, including elevated serum C-reactive protein and lower plasma TNF levels, associate with positive cough aerosol cultures. Notably, we find pre-treatment whole blood transcriptional profiles associate with aerosol culture status, independent of bacillary load. These findings suggest that tuberculosis infectiousness is associated with epidemiologic characteristics and inflammatory signatures and that these features may identify highly infectious persons.

The prognostic potential of mammographic growth rate of invasive breast cancer in the Nijmegen breast cancer screening cohort

OBJECTIVES

Insight into the aggressiveness of potential breast cancers found in screening may optimize recall decisions. Specific growth rate (SGR), measured on mammograms, may provide valuable prognostic information. This study addresses the association of SGR with prognostic factors and overall survival in patients with invasive carcinoma of no special type (NST) from a screened population.

METHODS

In this historic cohort study, 293 women with NST were identified from all participants in the Nijmegen screening program (2003-2007). Information on clinicopathological factors was retrieved from patient files and follow-up on vital status through municipalities. On consecutive mammograms, tumor volumes were estimated. After comparing five growth functions, SGR was calculated using the best-fitting function. Regression and multivariable survival analyses described associations between SGR and prognostic factors as well as overall survival.

RESULTS

Each one standard deviation increase in SGR was associated with an increase in the Nottingham prognostic index by 0.34 [95% confidence interval (CI): 0.21-0.46]. Each one standard deviation increase in SGR increased the odds of a tumor with an unfavorable subtype (based on histologic grade and hormone receptors; odds ratio 2.14 [95% CI: 1.45-3.15]) and increased the odds of diagnosis as an interval cancer (versus screen-detected; odds ratio 1.57 [95% CI: 1.20-2.06]). After a median of 12.4 years of follow-up, 78 deaths occurred. SGR was not associated with overall survival (hazard ratio 1.12 [95% CI: 0.87-1.43]).

CONCLUSIONS

SGR may indicate prognostically relevant differences in tumor aggressiveness if serial mammograms are available. A potential association with cause-specific survival could not be determined and is of interest for future research.

Parametric g-formula for Testing Time-Varying Causal Effects: What It Is, Why It Matters, and How to Implement It in Lavaan

Psychologists leverage longitudinal designs to examine the causal effects of a focal predictor (i.e., treatment or exposure) over time. But causal inference of naturally observed time-varying treatments is complicated by treatment-dependent confounding in which earlier treatments affect confounders of later treatments. In this tutorial article, we introduce psychologists to an established solution to this problem from the causal inference literature: the parametric g-computation formula. We explain why the g-formula is effective at handling treatment-dependent confounding. We demonstrate that the parametric g-formula is conceptually intuitive, easy to implement, and well-suited for psychological research. We first clarify that the parametric g-formula essentially utilizes a series of statistical models to estimate the joint distribution of all post-treatment variables. These statistical models can be readily specified as standard multiple linear regression functions. We leverage this insight to implement the parametric g-formula using lavaan, a widely adopted R package for structural equation modeling. Moreover, we describe how the parametric g-formula may be used to estimate a marginal structural model whose causal parameters parsimoniously encode time-varying treatment effects. We hope this accessible introduction to the parametric g-formula will equip psychologists with an analytic tool to address their causal inquiries using longitudinal data.

Through a teratological lens: A narrative review of exposure to stress and drugs of abuse during pregnancy on neurodevelopment

Teratological research shows that both prenatal stress and prenatal substance exposure have a significant impact on neurodevelopmental outcomes in children. Using human research, the purpose of this narrative review is to explore the degree to which these exposures may represent complex prenatal and postnatal risks for the development of cognition and behavior in children. An understanding of the HPA axis and its function during pregnancy as well as the types and operationalization of prenatal stress provide a context for understanding the direct and indirect mechanisms by which prenatal stress affects brain and behavior development. In turn, prenatal substance exposure studies are evaluated for their importance in understanding variables that indicate a potential interaction with prenatal stress including reactivity to novelty, arousal, and stress reactivity during early childhood. The similarities and differences between prenatal stress exposure and prenatal substance exposure on neurodevelopmental outcomes including arousal and emotion regulation, cognition, behavior, stress reactivity, and risk for psychopathology are summarized. Further considerations for teratological studies of prenatal stress and/or substance exposure include identifying and addressing methodological challenges, embracing the complexity of pre-and postnatal environments in the research, and the importance of incorporating parenting and resilience into future studies.

Readmissions at 30 Days and 1 Year for Implant-Associated Complications Following Primary Total Hip and Knee Arthroplasty: A Population-Based Study of 34,392 Patients Across Austria

BACKGROUND

The primary aim of this study was to assess 30-day and 1-year rates for unplanned readmission due to implant-associated complications following total hip (THA) or total knee arthroplasty (TKA) in Austria. Secondary endpoints were reasons for readmission and differences in revision risk depending on demographics and hospital size.

METHODS

Data on patients receiving THA (n = 18,508) or TKA (n = 15,884) in orthopaedic and trauma units across Austria within a 1-year period (January 2021 to December 2021) were retrieved from a government-maintained database. The absolute and relative frequencies of unplanned readmissions were calculated. Risk factors for 30-day and 1-year readmission following THA or TKA due to implant-associated complications were investigated.

RESULTS

The 30-day and 1-year readmission rates for any implant-associated complication were 1.0% (339 of 34,392) and 3.0% (1,024 of 34,392), respectively. Relative to the overall readmission rate for any complication at 30 days (n = 1,952) and 1 year (n = 12,109), readmission rates for implant-associated complications were 17.4 and 8.5%, respectively. The 30-day readmission rates were higher in THA (1.2%) than TKA patients (0.8%; P = 0.001), while it was the opposite at 1 year (THA, 2.7%; TKA, 3.3%; P < 0.001). Mechanical complications (554 of 1,024) were the most common reason for 1-year readmission. Prolonged length of in-hospital stay independently associated with increased 1-year readmission risk in THA and TKA patients. Treatment at large-sized hospitals was associated with a higher 1-year readmission risk in TKA patients.

CONCLUSIONS

The 30-day and 1-year readmission rates for implant-associated complications following THA or TKA in Austria are lower than reported in other countries, with similar risk factors and reasons for readmission. Considering that almost 20% of unplanned hospital readmissions following total joint arthroplasty are attributable to implant-associated complications, optimization of in-hospital and postdischarge medical care for these patients is warranted.

Rhabdomyolysis, Acute Kidney Injury, and Mortality in Ebola Virus Disease: Retrospective Analysis of Cases From the Eastern Democratic Republic of the Congo, 2019

BACKGROUND

Skeletal muscle injury in Ebola virus disease (EVD) has been reported, but its association with morbidity and mortality remains poorly defined.

METHODS

This retrospective study included patients admitted to 2 EVD treatment units over an 8-month period in 2019 during an EVD epidemic in the Democratic Republic of the Congo.

RESULTS

An overall 333 patients (median age, 30 years; 58% female) had at least 1 creatine kinase (CK) measurement (n = 2229; median, 5/patient [IQR, 1-11]). Among patients, 271 (81%) had an elevated CK level (>380 U/L); 202 (61%) had rhabdomyolysis (CK >1000 IU/L); and 45 (14%) had severe rhabdomyolysis (≥5000 U/L). Among survivors, the maximum CK level was a median 1600 (IQR, 550-3400), peaking 3.4 days after admission (IQR, 2.3-5.5) and decreasing thereafter. Among fatal cases, the CK rose monotonically until death, with a median maximum CK level of 2900 U/L (IQR, 1500-4900). Rhabdomyolysis at admission was an independent predictor of acute kidney injury (adjusted odds ratio, 2.2 [95% CI, 1.2-3.8]; P = .0065) and mortality (adjusted hazard ratio, 1.7 [95% CI, 1.03-2.9]; P = .037).

CONCLUSIONS

Rhabdomyolysis is associated with acute kidney injury and mortality in patients with EVD. These findings may inform clinical practice by identifying laboratory monitoring priorities and highlighting the importance of fluid management.

Association of colchicine use with cardiovascular and limb events in peripheral artery disease: Insights from a retrospective cohort study

BACKGROUND AND AIMS

Colchicine has demonstrated efficacy in treating coronary artery disease, but its efficacy in peripheral artery disease (PAD) remains uncertain. This study aims to address this gap in knowledge.

METHODS

A retrospective cohort study was conducted using the TriNetX Network, selecting patients with lower limb PAD between January 1, 2011, and January 1, 2024. Colchicine users were matched 1:1 with non-users through propensity score matching, considering demographics, medical conditions, medications, and psychosocial factors. The primary outcome was a composite of major adverse cardiovascular and limb events (MACLE) - including lower limb amputation, revascularization for lower limb ischemia, acute myocardial infarction, ischemic stroke, and all-cause mortality - over a ten-year follow-up.

RESULTS

From 53,568 colchicine-treated and 1,499,969 untreated patients with lower limb PAD, 52,350 pairs were successfully matched. Over ten years, colchicine was associated with a significant reduction in MACLE (hazard ratio, [HR] 0.90, 95% CI 0.88-0.92, p < 0.001), any lower limb amputation (HR 0.84, 95% CI 0.75-0.94, p = 0.002), revascularization for lower limb ischemia (HR 0.85, 95% CI 0.82-0.88, p < 0.001), major adverse cardiovascular events (HR 0.93, 95% CI 0.91-0.95, p < 0.001), and all-cause mortality (HR 0.90, 95% CI 0.87-0.92, p < 0.001). It also result in a reduced risk of ischemic stroke (HR 0.95, 95% CI 0.92-0.98, p = 0.001), but not of acute myocardial infarction (HR 0.98, 95% CI 0.95-1.01, p = 0.24).

CONCLUSIONS

Colchicine significantly reduced major adverse cardiovascular and limb events in patients with lower limb PAD, supporting the need for further investigation.

Association of back pain with all-cause and cause-specific mortality among older men: a cohort study

OBJECTIVE

We evaluated whether more severe back pain phenotypes-persistent, frequent, or disabling back pain-are associated with higher mortality rate among older men.

METHODS

In this secondary analysis of a prospective cohort, the Osteoporotic Fractures in Men (MrOS) study, we evaluated mortality rates by back pain phenotype among 5215 older community-dwelling men (mean age, 73 years, SD = 5.6) from 6 sites in the United States. The primary back pain measure used baseline and Year 5 back pain questionnaire data to characterize participants as having no back pain, nonpersistent back pain, infrequent persistent back pain, or frequent persistent back pain. Secondary measures of back pain from the Year 5 questionnaire included disabling back pain phenotypes. The main outcomes measured were all-cause and cause-specific death.

RESULTS

After the Year 5 exam, during up to 18 years of follow-up (mean follow-up = 10.3 years), there were 3513 deaths (1218 cardiovascular, 764 cancer, 1531 other). A higher proportion of men with frequent persistent back pain versus no back pain died (78% versus 69%; sociodemographic-adjusted HR = 1.27, 95% CI = 1.11-1.45). No association was evident after further adjustment for health-related factors, such as self-reported general health and comorbid chronic health conditions (fully adjusted HR = 1.00; 95% CI = 0.86-1.15). Results were similar for cardiovascular deaths and other deaths, but we observed no association of back pain with cancer deaths. Secondary back pain measures, including back-related disability, were associated with increased mortality risk that remained statistically significant in fully adjusted models.

CONCLUSION

Although frequent persistent back pain was not independently associated with risk of death in older men, additional secondary disabling back pain phenotypes were independently associated with increased mortality rate. Future investigations should evaluate whether improvements in disabling back pain affect general health and well-being or risk of death.

Occupation and COVID-19: Lessons From the Pandemic

Recognition that an individual's job could affect the likelihood of contracting coronavirus disease 2019 created challenges for investigators who sought to understand and prevent the transmission of severe acute respiratory syndrome coronavirus 2. Considerable research resources were devoted to separating the effects of occupational from nonoccupational risk factors. This commentary highlights results from studies that adjusted for multiple nonoccupational risk factors while estimating the effects of occupations and occupational risk factors. Methods used in these studies will prove useful in future infectious disease epidemics and pandemics and may potentially enrich studies of other occupational infectious and noninfectious respiratory diseases.

Nutrition adequacy in the late period of the acute phase is associated with a lower risk of 30-day mortality in critically ill patients: A prospective cohort study

BACKGROUND

The provision of nutrition support for critically ill patients in the early phase of intensive care unit (ICU) admission plays a vital role in their recovery. However, there is still debate regarding the impact of nutrition adequacy of critical illness phases. We aimed to investigate whether nutrition adequacy in the acute phase (early and late periods) is associated with 30-day mortality in critically ill patients.

METHODS

We prospectively collected nutrition and clinical data from critically ill patients receiving exclusive enteral nutrition (EN) within the first 10 days of ICU admission. EN was classified as adequate when ≥80% of the prescribed EN was administered. Directed acyclic graphs were constructed to identify the minimum set of adjustment variables required to control for confounding factors. The relationships between energy and protein intake and 30-day mortality were assessed using the Cox regression analysis.

RESULTS

A total of 119 patients were evaluated (70 years old, 56.3% male, and 68.1% with medical admission). The 30-day mortality rate was 23%. After adjusting for confounders, in the late period (days 5-10), energy adequacy (hazard ratio [HR] =  0.960; 95% CI, 0.937-0.984) and protein adequacy (HR = 0.960; 95% CI, 0.937-0.982) were predictors of 30-day mortality. No associations were observed in the early period (days 1-4) of the acute phase.

CONCLUSION

In critically ill patients, nutrition adequacy (≥80% EN) during days 5-10 in the ICU was associated with a lower risk of 30-day mortality.

Flawed MIREC fluoride and intelligence quotient publications: A failed attempt to undermine community water fluoridation

OBJECTIVE

To assess the evidence presented in a set of articles that use the Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study database to claim that community water fluoridation (CWF) is associated with harm to foetal and infant cognitive development.

METHODS

Critical appraisal of measurements and processes in the MIREC database, and articles derived therefrom. MIREC's cohort is approximately 2000 pregnant women recruited in 10 centres across Canada, 2008-2011, leading to measuring 512 children aged 3-6 years in six cities. Fluoride exposure was measured by city fluoridation status, self-reports and maternal spot urine samples. Intelligence Quotient (IQ) was measured using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) by different assessors in each city.

RESULTS

MIREC's fluoride and IQ measurements are invalid and therefore cannot support the claim that CWF is associated with IQ decline in children.

CONCLUSIONS

The MIREC fluoride-IQ articles' results should be considered unacceptable for legal and policy purposes; other water fluoridation studies and systematic reviews show no effect of fluoridation on cognition.

Vitamin D status of pregnant women with obesity in the UK and its association with pregnancy outcomes: a secondary analysis of the UK Pregnancies Better Eating and Activity Trial (UPBEAT) study

Prenatal vitamin D deficiency is widely reported and may affect perinatal outcomes. In this secondary analysis of the UK Pregnancies Better Eating and Activity Trial, we examined vitamin D status and its relationship with selected pregnancy outcomes in women with obesity (BMI ≥ 30 kg/m2) from multi-ethnic inner-city settings in the UK. Determinants of vitamin D status at a mean of 17 ± 1 weeks' gestation were assessed using multivariable linear regression and reported as percent differences in serum 25-hydroxyvitamin D (25(OH)D). Associations between 25(OH)D and clinical outcomes were examined using logistic regression. Among 1089 participants, 67 % had 25(OH)D < 50 nmol/l and 26 % had concentrations < 25 nmol/l. In fully adjusted models accounting for socio-demographic and anthropometric characteristics, 25(OH)D was lower among women of Black (% difference = -33; 95 % CI: -39, -27), Asian (% difference = -43; 95 % CI: -51, -35) and other non-White (% difference = -26; 95 % CI: -35, -14) ethnicity compared with women of White ethnicity (n 1086; P < 0·001 for all). In unadjusted analysis, risk of gestational diabetes was greater in women with 25(OH)D < 25 nmol/l compared with ≥ 50 nmol/l (OR = 1·58; 95 % CI: 1·09, 2·31), but the magnitude of effect estimates was attenuated in the multivariable model (OR = 1·33; 95 % CI: 0·88, 2·00). There were no associations between 25(OH)D and risk of preeclampsia, preterm birth or small for gestational age or large-for-gestational-age delivery. These findings demonstrate low 25(OH)D among pregnant women with obesity and highlight ethnic disparities in vitamin D status in the UK. However, evidence for a greater risk of adverse perinatal outcomes among women with vitamin D deficiency was limited.

Casgevy: Innovative Medicinal Products Require Innovative Approaches to Regulatory Assessment

Casgevy (exa-cel) is an autologous cellular therapy modified ex vivo by a CRISPR-Cas9-mediated gene-editing technology. For Casgevy to be granted the indication in transfusion-dependent β-thalassemia, one single-arm trial was submitted which was not amenable to conventional statistical analysis of 'effect of cause'. Therefore, an analysis was conducted on the basis of 'cause of effect' making use of the scheme described by Toulmin coupled to an analysis of causal inference. Based on the current data within the submitted study: subjects with transfusion-dependent β-thalassemia no longer needed a red blood cell transfusion with a 93-percent probability if and only if administered Casgevy; PNS = 93%. It is acknowledged that unknown elements of safety may yet be revealed by long-term follow-up of recipients of Casgevy. Its durability of efficacy is, at present, also an unknown that may also be ascertained by long-term follow-up of recipients. The limitations of a causal analysis are related to assumptions of the proposed causal structure which may not capture the complexity of the real world. Overall, the claim that Casgevy is indicated to treat people with transfusion-dependent β-thalassemia is considered to be supported by the results of the submitted study; the benefit-risk evaluation of Casgevy is found to be positive.

Wearable device-measured moderate to vigorous physical activity and risk of degenerative aortic valve stenosis

BACKGROUND AND AIMS

Physical activity has proven effective in preventing atherosclerotic cardiovascular disease, but its role in preventing degenerative valvular heart disease (VHD) remains uncertain. This study aimed to explore the dose-response association between moderate to vigorous physical activity (MVPA) volume and the risk of degenerative VHD among middle-aged adults.

METHODS

A full week of accelerometer-derived MVPA data from 87 248 UK Biobank participants (median age 63.3, female: 56.9%) between 2013 and 2015 were used for primary analysis. Questionnaire-derived MVPA data from 361 681 UK Biobank participants (median age 57.7, female: 52.7%) between 2006 and 2010 were used for secondary analysis. The primary outcome was the diagnosis of incident degenerative VHD, including aortic valve stenosis (AS), aortic valve regurgitation (AR), and mitral valve regurgitation (MR). The secondary outcome was VHD-related intervention or mortality.

RESULTS

In the accelerometer-derived MVPA cohort, 555 incident AS, 201 incident AR, and 655 incident MR occurred during a median follow-up of 8.11 years. Increased MVPA volume showed a steady decline in AS risk and subsequent AS-related intervention or mortality risk, levelling off beyond approximately 300 min/week. In contrast, its association with AR or MR incidence was less apparent. The adjusted rates of AS incidence (95% confidence interval) across MVPA quartiles (Q1-Q4) were 11.60 (10.20, 13.20), 7.82 (6.63, 9.23), 5.74 (4.67, 7.08), and 5.91 (4.73, 7.39) per 10 000 person-years. The corresponding adjusted rates of AS-related intervention or mortality were 4.37 (3.52, 5.43), 2.81 (2.13, 3.71), 1.93 (1.36, 2.75), and 2.14 (1.50, 3.06) per 10 000 person-years, respectively. Aortic valve stenosis risk reduction was also observed with questionnaire-based MVPA data [adjusted absolute difference Q4 vs. Q1: AS incidence, -1.41 (-.67, -2.14) per 10 000 person-years; AS-related intervention or mortality, -.38 (-.04, -.88) per 10 000 person-years]. The beneficial association remained consistent in high-risk populations for AS, including patients with hypertension, obesity, dyslipidaemia, and chronic kidney disease.

CONCLUSIONS

Higher MVPA volume was associated with a lower risk of developing AS and subsequent AS-related intervention or mortality. Future research needs to validate these findings in diverse populations with longer durations and repeated periods of activity monitoring.

What drives wild boar density and population growth in Mediterranean environments?

Accurate prediction of fluctuations of wildlife local number of individuals is crucial for effective population management to minimise human-wildlife conflicts. Climate, habitat, food availability, and density dependence are among the main factors influencing mammalian population dynamics. In southern Europe, precipitation and temperature, particularly during summer have been suggested as key factors affecting wild boar (Sus scrofa L.). However, there is uncertainty regarding the role of these factors and the mechanisms driving population fluctuations. This study utilized long-term data of wild boar populations from 14 study sites collected for 23 years in Catalonia, Spain, to analyse the factors that drive population density and growth rate. Generalized Additive Mixed Models (GAMM) explained respectively, 94 % and 65 % of the density and growth rate variability. Spring precipitation in both current and previous year, female weight, and forest cover (particularly above 60 %) were directly associated with higher wild boar densities and population growth rates. The interaction between crop cover and total annual precipitation also played a significant role in determining population density. Higher densities were linked to lower population growth in the following year, likely due to a density-dependent process. These results suggest that the expected decrease in rainfall linked with global warming may limit the availability of natural resources and potentially slow wild boar population growth. Nevertheless, wild boar can exploit alternative anthropogenic food sources, potentially leading to an increase of human-wildlife conflicts. Therefore, incorporating management policies aimed at restricting wild boar access to human food sources is key for controlling their reproductive output. Additionally, landscape management strategies targeted at diminishing refuge and resource availability in regions experiencing high wild boar impact are essential for contributing to sustainable coexistence between wild boars and human populations.

Music-Making and Depression and Anxiety Before and During the COVID-19 Pandemic-Results From the NAKO Cohort Study in Germany

Objectives

To investigate the association of musical activity with mental health during the COVID-19 pandemic.

Methods

A total of 3,666 participants reported their musical activity before and mental health indicators before and during the pandemic. Depression was assessed with the Patient Health Questionnaire, anxiety with the Generalized Anxiety Disorder scale. The association between mental health scores and musical activities was investigated using linear regression.

Results

Within the last 12 months, 22.1% of the participants reported musical activity (15.1% singing, 14.5% playing an instrument). Individuals with frequent singing as their main musical activity had higher scores before the pandemic than non-musicians and the worsening during the pandemic was more pronounced compared to non-musicians. Instrumentalists tended to have slightly lower scores than non-musicians indicating a possible beneficial effect of playing an instrument on mental health.

Conclusion

The pandemic led to a worsening of mental health, with singers being particularly affected. Singers showed poorer mental health before the pandemic. The tendency for instrumentalists to report lower depression scores compared to non-musicians may support the hypothesis that music-making has a beneficial effect on health.

Inverse probability weighting for self-selection bias correction in the investigation of social inequality in mortality

BACKGROUND

Empirical evaluation of inverse probability weighting (IPW) for self-selection bias correction is inaccessible without the full source population. We aimed to: (i) investigate how self-selection biases frequency and association measures and (ii) assess self-selection bias correction using IPW in a cohort with register linkage.

METHODS

The source population included 17 936 individuals invited to the Copenhagen Aging and Midlife Biobank during 2009-11 (ages 49-63 years). Participants counted 7185 (40.1%). Register data were obtained for every invited person from 7 years before invitation to the end of 2020. The association between education and mortality was estimated using Cox regression models among participants, IPW participants and the source population.

RESULTS

Participants had higher socioeconomic position and fewer hospital contacts before baseline than the source population. Frequency measures of participants approached those of the source population after IPW. Compared with primary/lower secondary education, upper secondary, short tertiary, bachelor and master/doctoral were associated with reduced risk of death among participants (adjusted hazard ratio [95% CI]: 0.60 [0.46; 0.77], 0.68 [0.42; 1.11], 0.37 [0.25; 0.54], 0.28 [0.18; 0.46], respectively). IPW changed the estimates marginally (0.59 [0.45; 0.77], 0.57 [0.34; 0.93], 0.34 [0.23; 0.50], 0.24 [0.15; 0.39]) but not only towards those of the source population (0.57 [0.51; 0.64], 0.43 [0.32; 0.60], 0.38 [0.32; 0.47], 0.22 [0.16; 0.29]).

CONCLUSIONS

Frequency measures of study participants may not reflect the source population in the presence of self-selection, but the impact on association measures can be limited. IPW may be useful for (self-)selection bias correction, but the returned results can still reflect residual or other biases and random errors.

Sugar types, genetic predictors of the gut microbiome, and the risk of chronic kidney disease: a prospective cohort study

Background: Emerging studies suggest that focusing on the intake of specific types or sources of sugars may yield greater benefits in preventing chronic kidney disease (CKD). Objective: We aimed to investigate the associations between free and non-free sugar intakes and CKD risk as well as the potential sugar type-gut microbiome interactions. Methods: A total of 138 064 participants from the UK Biobank were included in this prospective study. The free and non-free sugar intakes were assessed using repeated web-based 24-hour dietary recalls. A cause-specific competing risk model was used to estimate hazard ratios (HRs) and the corresponding confidence intervals (CIs) of incident CKD, treating deaths before incident CKD as competing events. Results: During a median follow-up of 10.5 years, 2,923 participants (2.1%) developed CKD. The free sugar intake was positively associated with the risk of CKD (HRquartile 4 vs. quartile 1 = 1.32, 95% CI = 1.18, 1.47), with a nonlinear relationship (P for nonlinearity = 0.01, the risk increased rapidly after free sugars made up 10% of the total energy). The non-free sugar intake was inversely associated with CKD risk (HRquartile 4 vs. quartile 1 = 0.68, 95% CI = 0.60, 0.77), with an L-shaped nonlinear curve (p for nonlinearity = 0.01, the turning point was at 13.5% of the total energy). We found that the associations between free sugar and non-free sugar intakes and CKD risk were more pronounced in participants with high genetically predicted gut microbial abundance. Furthermore, a significant interaction was observed between the genetically predicted gut microbial abundance and non-free sugar intake (P for interaction = 0.04). Conclusion: A higher intake of free sugars was associated with an elevated risk of CKD, whereas a higher intake of non-free sugars was associated with a reduced risk of CKD. The impact of free sugar intake and non-free sugar intake may be modified by the gut microbial abundance.

Occupational, academic, and personal determinants of wellbeing and psychological distress in residents: results of a survey in Lyon, France

Introduction

The mental health of residents is a growing significant concern, particularly with respect to hospital and university training conditions. Our goal was to assess the professional, academic, and psychological determinants of the mental health status of all residents of the academy of Lyon, France.

Materials and methods

The Health Barometer of Lyon Subdivision Residents (BASIL) is an initiative which consists in proposing a recurrent online survey to all residents in medicine, pharmacy, and dentistry, belonging to the Lyon subdivision. The first of these surveys was conducted from May to July 2022. Participants should complete a series of validated questionnaires, including the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS), and the Kessler Psychological Distress Scale (K6), respectively, and ad-hoc questions assessing their global health and hospital and academic working conditions. A Directed Acyclic Graph (DAG) analysis was conducted prior to multivariable analyses, to explore the determinants associated with low wellbeing (WEMWBS <43) and high psychological distress (K6 ≥ 13).

Results

A total of 904 residents (response rate: 46.7%) participated in the survey. A low level of wellbeing was observed in 23% of participants, and was significantly associated to job strain (OR = 2.18; 95%CI = [1.32-3.60]), low social support (OR = 3.13; 95%CI = [2.05-4.78]) and the experience of very poor university teaching (OR = 2.51; 95%CI = [1.29-4.91]). A high level of psychological distress was identified for 13% of participants, and associated with low social support (OR = 2.41; 95%CI = [1.48-3.93]) and the experience of very poor university teaching (OR = 2.89, 95%CI = [1.16-7.21]).

Conclusion

Hospital working conditions, social support, and the perception of teaching quality, were three major determinants of wellbeing and psychological distress among health profession residents. Demographic determinants, personal life and lifestyle habits were also associated. This supports a multilevel action in prevention programs aiming to enhance wellbeing and reduce mental distress in this specific population and local organizational specificities.

The prognostic value of tumor budding in a thoroughly characterized stage II colon cancer population in the context of a national screening program

Tumor budding as a prognostic marker in colorectal cancer has not previously been investigated in a cohort of screened stage II colon cancer patients. We assessed the prognostic significance of tumor budding in a thoroughly characterized stage II colon cancer population comprising surgically resected patients in the Region of Southern Denmark from 2014 to 2016. Tumors were re-staged according to the 8th edition of UICC TNM Classification, undergoing detailed histopathological evaluation and tumor budding assessment following guidelines from the International Tumor Budding Consensus Conference. Prognostic evaluation utilized Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models for time to recurrence (TTR), recurrence-free survival (RFS), and overall survival (OS). Out of 497 patients, 20% were diagnosed through the national colorectal cancer screening program. High-grade tumor budding (Bd3) was found in 19% of tumors and was associated with glandular subtype, perineural invasion, mismatch repair proficient tumors, and tumor recurrence (p < 0.001, p < 0.001, p = 0.045, and p = 0.007 respectively). In multivariable Cox regression, high-grade budding was a significant prognostic factor for TTR compared to low-grade (Bd3 HR 2.617; p = 0.007). An association between tumor budding groups and RFS was observed, and the difference was significant in univariable analysis for high-grade compared to low-grade tumor budding (Bd3 HR 1.461; p = 0.041). No significant differences were observed between tumor budding groups and OS. High-grade tumor budding is a predictor of recurrence in a screened population of patients with stage II colon cancer and should be considered a high-risk factor in a shared decision-making process when stratifying patients to adjuvant chemotherapy.

Building Learning Healthcare Systems for Critical Care Medicine

Learning healthcare systems are an evolving way of integrating informatics, analytics, and continuous improvement into daily practice in healthcare. This article discusses strategies to build learning healthcare systems for critical care medicine.

Directed acyclic graphs in clinical research

Directed acyclic graphs (DAGs), or causal diagrams, are graphical representations of causal structures that can be used in medical research to understand and illustrate potential bias, including bias arising from confounding, selection, and misclassification. Further, they provide guidance for researchers about how to address a potential bias.

Childhood maltreatment and trajectories of cardiometabolic health across the reproductive life span among individuals with a first birth during the Coronary Artery Risk Development in Young Adults Study

OBJECTIVE

Childhood adversity is associated with poor cardiometabolic health in adulthood; little is known about how this relationship evolves through childbearing years for parous individuals. The goal was to estimate differences in cardiometabolic health indicators before, during and after childbearing years by report of childhood maltreatment in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort study.

METHODS

Including 743 individuals nulliparous at baseline (1985-1986) with one or more pregnancies >20 weeks during follow-up (1986-2022), we fit segmented linear regression models to estimate mean differences between individuals reporting or not reporting childhood maltreatment (physical or emotional) in waist circumference, triglycerides, high-density lipoprotein cholesterol, systolic and diastolic blood pressure, fasting glucose, and body mass index (BMI) prior to, during, and following childbearing years using generalized estimating equations, allowing for interaction between maltreatment and time within each segment, and adjusting for total parity, parental education, and race (Black or white, self-reported).

RESULTS

Individuals reporting maltreatment (19%; 141) had a greater waist circumference (post-childbearing: +2.9 cm, 95% CI (0.7, 5.0), higher triglycerides [post-childbearing: +8.1 mg/dL, 95% CI (0.7, 15.6)], and lower HDL cholesterol [post-childbearing: -2.1 mg/dL, 95% CI (-4.7, 0.5)] during all stages compared to those not reporting maltreatment. There were not meaningful differences in blood pressure, fasting glucose, or BMI. Individuals who reported maltreatment did not report faster changes over time.

CONCLUSION

Differences in some aspects of cardiometabolic health between individuals reporting versus not reporting childhood maltreatment were sustained across reproductive life stages, suggesting potentially persistent impacts of childhood adversity.

Epidemiological insights into the burden of feline upper respiratory tract infections in Queensland RSPCA shelters

INTRODUCTION

Feline upper respiratory tract infection (FURTI) is a severe problem in animal shelters where there is high turnover of populations and compromised immunity. This retrospective cohort study explores associations of potential animal-based and environmental-based factors with the risk of FURTI, where a previously modelled infection classification is used as the outcome of interest. The study type is a retrospective cohort and the measures of association include Odds Ratios and conditional predictions.

OBJECTIVES

To gain epidemiological insights into variation in FURTI using retrospective data from one of Australia's leading animal shelters.

METHODS

We stratified FURTI by admission and environmental variables. Predicted infection status, obtained using a machine-learning classifier trained on clinical text (accuracy 0.95 [CI 0.92, 0.97]), was used as the outcome of interest. Prior assumptions were represented by a causal framework or a direct acyclic graph (DAG), which informed creation of multiple Bernoulli models with an observational and prior component.

RESULTS

We analysed 43,431 feline entries over 8 years. Males were 1.24 (95% CI 1.19 to 1.31) times more likely than females to be classified as positive, while already desexed animals were only 0.68 (95% CI 0.60 to 0.72) as likely to be classified as positive compared to those not desexed on entry. Cats (>4 months) were twice as likely (95% CI 1.91 to 2.09) as kittens (0-4 months) to be classified positive. Animals entering the shelter as seized by the inspectorate (n = 415) were more likely to be classified positive compared to animals from other sources. Predicted infection probability increased in winter and showed a linear pattern with how full the shelter was.

CONCLUSION

This study estimates the association between animal and environmental variables of interest and FURTI classification status, thus better interpreting the distribution of disease as predicted by a previously uninterpretable model. This analysis gives much needed insight into the types of changes in an animal's environment that can impact final animal outcomes.

Environmental predictors of Escherichia coli concentration at marine beaches in Vancouver, Canada: a Bayesian mixed-effects modelling analysis

Understanding historical environmental determinants associated with the risk of elevated marine water contamination could enhance monitoring marine beaches in a Canadian setting, which can also inform predictive marine water quality models and ongoing climate change preparedness efforts. This study aimed to assess the combination of environmental factors that best predicts Escherichia coli (E. coli) concentration at public beaches in Metro Vancouver, British Columbia, by combining the region's microbial water quality data and publicly available environmental data from 2013 to 2021. We developed a Bayesian log-normal mixed-effects regression model to evaluate predictors of geometric E. coli concentrations at 15 beaches in the Metro Vancouver Region. We identified that higher levels of geometric mean E. coli levels were predicted by higher previous sample day E. coli concentrations, higher rainfall in the preceding 48 h, and higher 24-h average air temperature at the median or higher levels of the 24-h mean ultraviolet (UV) index. In contrast, higher levels of mean salinity were predicted to result in lower levels of E. coli. Finally, we determined that the average effects of the predictors varied highly by beach. Our findings could form the basis for building real-time predictive marine water quality models to enable more timely beach management decision-making.

Diffusion of medications for opioid use disorder treatment in jail settings: a convergent mixed methods study of jail staff perspectives

BACKGROUND

Implementation of medications for opioid use disorder (MOUD) in jails varies by facility and across states. Organizational climate, including staff attitudes toward change and exposure to education, can influence perceptions of innovations like MOUD in jails. Using a mixed methods design, we aimed to understand the association between organizational climate and jail staff perceptions of MOUD.

METHODS

Jail staff (n = 111) who operate MOUD programs in 6 Massachusetts jails completed surveys that included the Organizational Readiness for Implementing Change (ORIC) survey. Random effects logistic regression models assessed associations between organizational climate and several outcomes of perceived MOUD efficacy, acceptability, and knowledge, while controlling for covariates. Jail staff (N = 61) participated in qualitative interviews and focus groups focused on organizational climate and knowledge diffusion, which we analyzed using inductive and deductive methods.

RESULTS

The results indicate that organizational change readiness on the ORIC was associated with positive perceptions of MOUD, and educational resources facilitated MOUD implementation. Greater ORIC was associated with higher perception of methadone as highly acceptable for jail populations (Odds ratio [OR] 2.3, 95% Confidence Interval [CI] 1.2 to 4.4), and high knowledge of methadone (OR 2.3, 95% CI 1.1 to 4.9), with similar magnitude of effects for buprenorphine. High levels of training for jail staff on methadone and buprenorphine were also associated with higher knowledge of these medications (Methadone: OR 7.2, 95% CI 2.2 to 23.2; Buprenorphine: OR 3.4, 95% CI 1.2 to 9.5). Qualitative results point towards the importance of organizational climate and elucidate educational strategies to improve staff perceptions of MOUD.

CONCLUSION

Results underscore the importance of organizational climate for successful implementation of jail MOUD programs and provide support for medication-specific educational resources as a facilitator of successful MOUD implementation in jail settings. Findings highlight implementation strategies that may improve jail staff perceptions of MOUD.

Risk of Early Childhood Caries Estimated by Maternal Dental Caries during Pregnancy: A Retrospective Cohort Study

OBJECTIVE

 Public policy promoting prenatal dental care to provide long-term prevention of early childhood caries (ECC) in offspring would require evidence regarding the ECC risk associated with maternal dental caries during pregnancy. This study evaluated that association using a design capable of assessing temporal relationships and considered a directed acyclic graph to guide the adjustment of pertinent confounders.

MATERIALS AND METHODS

 This retrospective cohort study analyzed data from 158 mother-child dyads attending care at Prachathipat Hospital, Pathum Thani, Thailand. Maternal dental caries data at their first visits to prenatal oral care from February 2012 to May 2017 were traced forwardly to match the oral health data of offspring who visited the hospital from May 2013 to March 2018.

RESULTS

 Univariable and multivariable fractional logit regression models along with the calculation of average marginal effects revealed that children born to two categories of mothers with 1 to 5 and ≥6 carious teeth during pregnancy would averagely develop 4.5 to 5 and 7.9 to 8.8 more carious teeth per 100 teeth than dental caries would occur in offspring of caries-free mothers.

CONCLUSION

 This evidence identified the role of maternal dental caries during pregnancy as a significant clinical risk indicator for ECC and supported the provision of prenatal dental care for mothers to prevent ECC in offspring.

Anxiety but not menopausal status influences the risk of long-COVID-19 syndrome in women living in Latin America

OBJECTIVE

To study sociodemographic and clinical factors associated with the long-COVID-19 syndrome among women living in Latin American countries using undirected and directed methods.

METHOD

We studied 347 patients with COVID-19 (confirmed by polymerase chain reaction) living in nine Latin American countries between May 2021 and July 2022, including 70 premenopausal, 48 perimenopausal, and 229 postmenopausal women. We compared the sociodemographic and general health information of women with (n = 164) and without (n = 183) the long-COVID-19 syndrome. They also completed the Connor-Davidson Resilience Scale, the Fear of COVID-19 Scale, the Jenkins Sleep Scale, and the Menopause Rating Scale to define the minimum set of variables for adjustment. We designed a directed acyclic graph (DAG) to identify factors related to the long-COVID-19 syndrome. Data were submitted to categorical logistic regression analyses. Results are reported as means and standard deviations or β-coefficients and 95 % confidence intervals.

RESULTS

Women with long-COVID-19 syndrome had a poor lifestyle, severe menopause symptoms, hypertension, insomnia, depression, anxiety, chronic diseases/conditions, risk of hospitalization, sleep disturbance, and low menopause-related quality of life compared to women without the syndrome. The DAG identified the following long-COVID-19 covariates: age, obesity, anxiety, depression, cancer, lifestyle, smoking, and menstrual status. A multivariable logistic model with these covariates indicated that anxiety is the only factor to be significantly associated with long-COVID-19 syndrome, whereas other covariates were confounding factors. There was no significant influence of menopausal status on the long-COVID-19 syndrome.

CONCLUSION

Among factors selected by the DAG, only anxiety was significantly associated with the long-COVID-19. There was no significant influence of the menopause status on the long-COVID-19 syndrome in the studied population.

Risk of long COVID and associated symptoms after acute SARS-COV-2 infection in ethnic minorities: A nationwide register-linked cohort study in Denmark

BACKGROUND

Ethnic minorities living in high-income countries have been disproportionately affected by Coronavirus Disease 2019 (COVID-19) in terms of infection rates, hospitalisations, and deaths; however, less is known about long COVID in these populations. Our aim was to examine the risk of long COVID and associated symptoms among ethnic minorities.

METHODS AND FINDINGS

We used nationwide register-based cohort data on individuals diagnosed with COVID-19 aged ≥18 years (n = 2,287,175) between January 2020 and August 2022 in Denmark. We calculated the risk of long COVID diagnosis and long COVID symptoms among ethnic minorities compared with native Danes using multivariable Cox proportional hazard regression and logistic regression, respectively. Among individuals who were first time diagnosed with COVID-19 during the study period, 39,876 (1.7%) were hospitalised and 2,247,299 (98.3%) were nonhospitalised individuals. Of the diagnosed COVID-19 cases, 1,952,021 (85.3%) were native Danes and 335,154 (14.7%) were ethnic minorities. After adjustment for age, sex, civil status, education, family income, and Charlson comorbidity index, ethnic minorities from North Africa (adjusted hazard ratio [aHR] 1.41, 95% confidence interval [CI] [1.12,1.79], p = 0.003), Middle East (aHR 1.38, 95% CI [1.24,1.55], p < 0.001), Eastern Europe (aHR 1.35, 95% CI [1.22,1.49], p < 0.001), and Asia (aHR 1.23, 95% CI [1.09,1.40], p = 0.001) had significantly greater risk of long COVID diagnosis than native Danes. In the analysis by largest countries of origin, the greater risks of long COVID diagnosis were found in people of Iraqi origin (aHR 1.56, 95% CI [1.30,1.88], p < 0.001), people of Turkish origin (aHR 1.42, 95% CI [1.24,1.63], p < 0.001), and people of Somali origin (aHR 1.42, 95% CI [1.07,1.91], p = 0.016). A significant factor associated with an increased risk of long COVID diagnosis was COVID-19 hospitalisation. The risk of long COVID diagnosis among ethnic minorities was more pronounced between January 2020 and June 2021. Furthermore, the odds of reporting cardiopulmonary symptoms (including dyspnoea, cough, and chest pain) and any long COVID symptoms were higher among people of North African, Middle Eastern, Eastern European, and Asian origins than among native Danes in both unadjusted and adjusted models. Despite including the nationwide sample of individuals diagnosed with COVID-19, the precision of our estimates on long COVID was limited to the sample of patients with symptoms who had contacted the hospital.

CONCLUSIONS

Belonging to an ethnic minority group was significantly associated with an increased risk of long COVID, indicating the need to better understand long COVID drivers and address care and treatment strategies in these populations.

Exploring the Influence of Social Class and Sex on Self-Reported Health: Insights from a Representative Population-Based Study

This study investigates the intricate interplay between social class, sex, and self-reported health (SRH) using data from the European Health Survey of Spain 2020 (EESE2020). Employing a cross-sectional design and a representative sample of 22,072 individuals, the analysis explores the persistence of disparities after adjusting for covariates, focusing on health-related variables. The study employs logistic regression models and directed acyclic graphs (DAGs) to delineate the direct effects of social class and sex on SRH, identifying a minimum adjustment set to control for confounding variables. Results reveal a gradient effect of social class on SRH, emphasizing the enduring impact of socioeconomic factors. Sex-based disparities in SRH diminish after considering additional health-related variables, highlighting the importance of a holistic approach. DAGs serve as transparent tools in disentangling complex relationships, guiding the identification of essential covariates. The study concludes that addressing health inequalities requires comprehensive strategies considering both individual health behaviours and socio-economic contexts. While recognizing limitations, such as the cross-sectional design, the findings contribute to a nuanced understanding of health disparities, informing evidence-based interventions and policies for a more equitable healthcare system.

The Association between Self-Care Activities and Depression in Adult Patients with Type 2 Diabetes in Saudi Arabia: A Cross-Sectional Web-Based Survey Study

This study examined the level of adherence to self-care behaviors among individuals with type 2 diabetes in Saudi Arabia and its connection with depression and demographic factors. A cross-sectional survey was conducted among diabetes patients using the Patient Health Questionnaire (PHQ-9) to measure depression and the Summary of Diabetes Self-Care Activities (SDSCA) to evaluate diabetes self-care activities. Among the 252 participants who completed the survey, 43.2% were older than 55 and 59% were men. The ordinal regression model showed an association between the PHQ-9 and SDSCA scores with an OR of 0.83 (95% CI: 0.71 to 0.96, p = 0.013). The PHQ-9 score was significantly associated with blood sugar monitoring (OR: 0.90 [95% CI: 0.82 to 0.99, p = 0.003]), exercise (OR: 0.88 [95% CI: 0.79 to 0.98, p = 0.002]), and diet (OR: 0.94 [95% CI: 0.85 to 1.03, p = 0.045]). Of all the diabetes-related factors, only a history of hospitalization and receiving diabetes education were found to be associated with improved self-care behaviors. In conclusion, a negative association was found between PHQ-9 scores and the SDSCA mean score and most daily diabetic self-care behavior components.

Leisure-Time Physical Activity and Falls With and Without Injuries Among Older Adult Women

Importance

Falls and fall-related injuries are common among older adults. Older adults are recommended to undertake 150 to 300 minutes of physical activity per week for health benefits; however, the association between meeting the recommended level of physical activity and falls is unclear.

Objectives

To examine whether associations exist between leisure-time physical activity and noninjurious and injurious falls in older women.

Design, Setting, and Participants

This population-based cohort study used a retrospective analysis of the Australian Longitudinal Study on Women's Health (ALSWH). ALSWH participants born from 1946 to 1951 who completed follow-up questionnaires in 2016 (aged 65-70 years) and 2019 (aged 68-73 years) were included. Statistical analysis was performed from September 2022 to February 2023.

Exposure

Self-reported weekly amounts (0, 1 to <150, 150 to <300, ≥300 minutes) and types of leisure-time physical activity, including brisk walking and moderate- and vigorous-intensity physical activity, in the 2016 survey.

Main outcome and measures

Noninjurious and injurious falls in the previous 12 months reported in the 2019 survey. Associations between leisure-time physical activity and falls were quantified using directed acyclic graph-informed multinomial logistic regression and presented in odds ratios (ORs) and 95% CIs.

Results

This study included 7139 women (mean [SD] age, 67.7 [1.5] years). Participation in leisure-time physical activity at or above the level recommended by the World Health Organization (150 to <300 min/wk) was associated with reduced odds of noninjurious falls (150 to <300 min/wk: OR, 0.74 [95% CI, 0.59-0.92]; ≥300 min/wk: OR, 0.66 [95% CI, 0.54-0.80]) and injurious falls (150 to <300 min/wk: OR, 0.70 [95% CI, 0.56-0.88]; ≥300 min/wk: OR, 0.77 [95% CI, 0.63-0.93]). Compared with women who reported no leisure-time physical activity, those who reported brisk walking (OR, 0.83 [95% CI, 0.70-0.97]), moderate leisure-time physical activity (OR, 0.81 [95% CI, 0.70-0.93]), or moderate-vigorous leisure-time physical activity (OR, 0.84 [95% CI, 0.70-0.99]) had reduced odds of noninjurious falls. No statistically significant associations were found between the types of leisure-time physical activity and injurious falls.

Conclusions and Relevance

Participation in leisure-time physical activity at the recommended level or above was associated with lower odds of both noninjurious and injurious falls. Brisk walking and both moderate and moderate-vigorous leisure-time physical activity were associated with lower odds of noninjurious falls.