Population-level Study Research Articles

Development of prediction models for liver metastasis in colorectal cancer based on machine learning: a population-level study.

Liver metastasis (LM) is of vital importance in making treatment-related decisions in patients with colorectal cancer (CRC). The aim of our study was to develop and validate prediction models for LM in CRC by making use of machine learning. We selected patients diagnosed with CRC from 2010 to 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. Four machine-learning methods, eXtreme gradient boost (XGB), decision tree (DT), random forest (RF), and support vector machine (SVM), were employed to develop a predictive model. The receiver operating characteristic (ROC) curves, decision curve analysis (DCA) curves and calibration curves were adopted to evaluate the model performance. The SHapley Additive exPlanation (SHAP) technique was chosen for visual analysis to enhance the interpretation of the outcomes of models. A total of 51,632 patients suffering from CRC were selected from the SEER database. Excellent accuracy of machine learning models was showed from ROC curves. In both the training and validation cohorts, calibration curves for the likelihood of LM demonstrated a high degree of concordance between model prediction and actual observation. The DCA indicated that each machine learning model can yield net benefits for both treat-none and treat-all strategies. Carcinoembryonic antigen (CEA) and N stage were identified as the most significant risk factors for LM based on the SHAP summary plot of the RF and XGB models. The XGB and RF were the best machine learning models among the four algorithms, of which CEA and N stage were identified as the most important risk factors related to LM.

Association between preterm birth and economic and educational outcomes in adulthood: A population-based matched cohort study.

Preterm birth (PTB) affects ~10% of births worldwide; however, most literature focused on short-term clinical outcomes, with much less focus on long-term socioeconomic outcomes after PTB. We examined associations between PTB and individuals' income, employment, and educational outcomes during early adulthood. We conducted a population-level matched cohort study including all live births in Canada between 1990 and 1996, followed until 2018. Outcomes included Employment income per year in 2018 CAD and employment between ages 18 and 28 years, postsecondary education enrollment (18-22 years), and maximum educational attainment at age 22-27 years. Mean differences and risk ratios (RR) and differences (RD) were estimated using generalized estimating equation regression models for economic outcomes and multinomial logistic regression models for educational outcomes. Of 2.4 million births, 7% were born preterm (0.3%, 0.6%, 0.8%, and 5.4% born extremely preterm (24-27 weeks), very preterm (28-31 weeks), moderately preterm (32-33 weeks), and late preterm (34-36 weeks) respectively). After matching on baseline characteristics (e.g., sex, province of birth, and parental demographics) and adjusting for age and period effects, preterm-born individuals, on average, had $958 CAD less employment income per year (95% CI: $854-$1062), 6% lower income per year, than term-born individuals, and were 2.13% less likely to be employed (1.98-2.29%). PTB was also negatively associated with university enrollment (RR 0.93 (0.91-0.94) and graduation with a university degree (RR 0.95 (0.94-0.97)). Mean income differences for those born 24-27 weeks were -$5,463 CAD per year (17% lower), and adjusted RR were 0.55 for university enrollment and graduation. In this population-based study, preterm birth was associated with lower economic and educational achievements at least until the late twenties. The associations were stronger with decreasing GA at birth. Policymakers, clinicians, and parents should be aware that the socioeconomic impact of PTB is not limited to the early neonatal period but extends into adulthood.

Bayesian Model Projecting Cardiovascular Disease Related Mortality Trends in the United States.

As future cardiovascular disease mortality trends have public health implications, we aimed to project ischemic heart disease (IHD), cerebrovascular disease (CeVD), and heart failure (HF) mortality rates for adults (40-79 years). In this population-level study, we linked the yearly mortality rates (per 100 000 US residents) (2000-2019) with IHD, CeVD, or HF as the primary cause of death from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research with the midyear US population estimates (2000-2035) for adults (40-79 years). We calculated the observed age-standardized mortality rates (2000-2019) (per 100 000 residents) (aSMR) and fitted Bayesian age-period-cohort models to project aSMR for IHD, CeVD, and HF up to 2035 in the United States. Between 2019 (last year of observed data) and 2035 (last year of projected results), the US population (40-79 years) will increase by 16% and age. The IHD aSMR will reduce from 111.9 (in 2019) to 81.8 (66.7-96.9) in 2035, an effect observed for all age groups. The CeVD aSMR will remain comparable between 2019 (37.4) and 2035 (38.6 [30.7-46.5]). The HF aSMR will increase from 16.5 in 2019 to reach 30.9 (13-48.8) in 2035; such increases were observed in all age groups. In the United States, between 2020 and 2035, the aSMR for IHD is expected to decrease, for CeVD will remain stable, and for HF will increase substantially. These data can inform resource allocation for future public health initiatives.

Development and validation of a clinical prediction tool to estimate survival in community-dwelling adults living with dementia: a protocol

IntroductionA clinical prediction tool to estimate life expectancy in community-dwelling individuals living with dementia could inform healthcare decision-making and prompt future planning. An existing Ontario-based tool for community-dwelling elderly individuals does not perform well in people living with dementia specifically. This study seeks to develop and validate a clinical prediction tool to estimate survival in community-dwelling individuals living with dementia receiving home care in Ontario, Canada.Methods and analysisThis will be a population-level retrospective cohort study that will use data in linked healthcare administrative databases at ICES. Specifically, data that are routinely collected from regularly administered assessments for home care will be used. Community-dwelling individuals living with dementia receiving home care at any point between April 2010 and March 2020 will be included (N≈200 000). The model will be developed in the derivation cohort (N≈140 000), which includes individuals with a randomly selected home care assessment between 2010 and 2017. The outcome variable will be survival time from index assessment. The selection of predictor variables will be fully prespecified and literature/expert-informed. The model will be estimated using a Cox proportional hazards model. The model’s performance will be assessed in a temporally distinct validation cohort (N≈60 000), which includes individuals with an assessment between 2018 and 2020. Overall performance will be assessed using Nagelkerke’s R2, discrimination using the concordance statistic and calibration using the calibration curve. Overfitting will be assessed visually and statistically. Model performance will be assessed in the validation cohort and in prespecified subgroups.Ethics and disseminationThe study received research ethics board approval from the Sunnybrook Health Sciences Centre (SUN-6138). Abstracts of the project will be submitted to academic conferences, and a manuscript thereof will be submitted to a peer-reviewed journal for publication. The model will be disseminated on a publicly accessible website (www.projectbiglife.com).Trial registration numberNCT06266325(clinicaltrials.gov).

A population-level study reveals hidden patterns in resting site choice of free-ranging dogs

Abstract Rest is an essential biological activity for all animals. Urban animals encounter multiple anthropogenic disturbances while resting. Since free-ranging dogs (FRDs) have survived as a population in the Global South for centuries, they provide a unique opportunity to study adaptation to the human-dominated landscape. In a field-based study over 3 years, we documented resting behaviour and site selection in 66 dog groups (284 dogs) in India. Eleven physical parameters of the resting sites, along with biological activities such as mating and pup-rearing, season, and the time of day, affected their choice of resting sites. The frequency-rank distribution of the unique combinations of the 11 parameters followed a power-law distribution, suggesting underlying biological reasons for the observed preferences. Seven of these parameters were most consistently involved in site choice, explaining around 24% of the observations. FRDs prefer to rest near resources at the centre of their territory, where they have maximum visibility and minimal anthropogenic disturbance. They prefer concrete surfaces with low insect presence. Our results suggest that the FRDs choose resting sites that enable better resource and territory defence, foraging effectiveness, and insect avoidance. Urban planners can use these insights to reduce situations of conflict and build more inclusive urban areas.

Associations between diabesity and mortality over 7 years: a Maltese population-level case study

Abstract Introduction Diabesity presents a growing global epidemic. Demographic and socioeconomic associations have been documented, yet, the literature on mortality risk associated with diabesity is scarce. The aim of this study was to assess whether diabetes and/or diabesity increas the risk of all-cause mortality across a period of 7 years at a population level. Methods A nation-wide health examination survey in Malta was conducted between 2014 and 2016. This collected sociodemographic information, bio-anthropometric measurements (waist circumference, body mass index [BMI], body adiposity index [BAI]) and blood samples. Mortality information was acquired in 2021 by cross-referencing with the national mortality register. Statistical analysis was conducted using chi-square tests and Cox proportional hazard models. Results A mortality rate of 1.67% was observed (n = 3947), with diabetes and obesity being responsible for 6.06% and 3.03% of deaths, respectively. Examining the deceased individuals alongside their baseline characteristics (2014-2015) revealed that 25.76% (CI95%: 16.75 - 37.44) had diabetes, and 30.30% (CI95%: 20.55 - 42.22) were obese. Diabetes was associated with significant mortality risk (HR: 2.65 CI95%: 1.20 - 5.85; p = 0.02), while diabesity showed borderline significance (p = 0.06). After adjustment for potential confounding factors the mortality risk linked to diabetes remained significant and BAI was the only anthropometric measurement positively associated with mortality. Conclusions These findings emphasise the urgency for comprehensive public health policies targeting the concurrent prevention and management of diabetes and obesity at a population level. Our results also indicate that incorporating body adiposity index (BAI) into risk assessment protocols may provide valuable insights into mortality risk prediction and inform tailored interventions. Key messages • Diabetes and a high BAI score were significantly associated with mortality in the Maltese population, while diabesity had moderate significance, emphasising the urgency of tackling this epidemic. • These findings call for broad health policies to address diabesity at a population level and suggest integrating BAI into risk assessment for better mortality prediction and tailored interventions.

Association between volume and cost in low-resection volume regions: a population-level study on pancreatoduodenectomy for pancreatic cancer patients.

Pancreatoduodenectomy (PD) is a highly complex, invasive, and costly surgical procedure. Limited evidence on the PD volume-cost relationship in countries with a low population density exists. This study aimed to investigate this issue in Australia. This retrospective cohort study included pancreatic cancer patients who had a PD at any public hospital in New South Wales, Australia between 2016 and 2019. The primary outcome was the total hospital cost during PD admission (not including patient financial burden). Study hospitals were grouped into low-volume hospitals (LVHs; <10 PDs per annum) or high-volume hospitals (HVHs). Multivariable modelling was applied to examine the association between volume and cost. Of 443 PDs, the median total hospital cost per patient at HVHs was AU$55398; significantly lower than that at LVHs (AU$62859; P = 0.001). After adjusting for available patient and clinical factors, the total cost per patient at LVHs was 22% higher than that of HVHs (adjusted estimate: 1.22, 95% CI: 1.08-1.37; P = 0.002). Similar patterns were found in three main cost components: 24% higher employee cost at LVHs than at HVHs (1.24, 95% CI: 1.10-1.41; P < 0.001), 15% higher operating cost (1.15, 95% CI: 1.00-1.31; P = 0.047), and 31% higher other costs (1.31, 95% CI: 1.12-1.53; P < 0.001). Performance of PDs at HVHs was associated with substantially lower hospital costs. Our findings demonstrate the likely economic benefit of centralizing PDs in countries with a relatively low population density. Future studies should investigate related patient financial burdens.

Special educational needs provision in primary education and its impact on unauthorised absence in children born with Cleft Lip and Palate: a population level study using linked health and education data

IntroductionWithout accounting for the underlying need for Special Educational Needs (SEN) provision, pupils with SEN in England have been shown to have higher rates of unauthorised absences. Objectives and ApproachOur objective was to understand the impact of SEN provision on unauthorised absences in children with an expected need for SEN, those born with Cleft Lip and/or Palate. We used linked health and educational records to investigate the relationship between three categories of SEN provision (No Provision versus SEN Support versus Education and Healthcare Plan (EHCP)) and unauthorised absences. We aimed to causally estimate the incident rate ratio (IRR) of SEN Support vs No Provision and EHCP vs SEN support on unauthorised absences between years one and six of primary education. Combining sociodemographic, educational and clinical variables from linked data, we used propensity-score based methods to adjust for non-randomised assignment to these categories of treatment. ConclusionsBetween academic years 2009 to 2019, we found common support between comparison groups No provision (n = 4350) and SEN support (n = 2009) only for children with Cleft lip and palate and only reported on these comparisons. Unadjusted estimates demonstrate a 22% increase in absences in children with SEN support over No Support (IRR: 1.22 95%CI: 1.10-1.34). Reweighting for need using data from linked health and education records demonstrated a 14% reduction in unauthorised absences (IRR: 0.86 95%CI: 0.76-0.97). ImplicationContrary to prior findings, by carefully matching on detailed linked health and education characteristics, we find SEN provision reduces unauthorised absences

Self-reported Ethnicity Changes over Time: A Population Level Study using Public Voter Databases

ObjectivesAdministrative databases such as voter registries contain a wealth of information about a large proportion of a population. This is especially true when longitudinal information about individuals is available, such as changes in their names, addresses, or self-reported ethnic attributes. Apparent changes in ethnic attributes might be due to perceptions of majority evaluations of ethnic groups. In this project, we analysed snapshots of a publicly available US voter database from 2015 to 2022, exploring if and how recent presidential elections impacted changes in voters' self-reported ethnic attributes. ApproachUsing bi-monthly snapshots of a publicly available US voter database from 2015 to 2022, we generated cohorts by linking active voters during seven twelve-month periods (2015/16 to 2021/22). These seven time periods included one mid-term and two presidential elections, and four control time spans before, between, and after these elections. We compared changes in self-reported ethnic attributes of voters during the times of elections versus the control time periods. ResultsPreliminary results reveal a substantial change to self-reported ethnic attributes during the periods leading to an election. A majority of such changes are by individuals from a specific ethnic group choosing not to report an ethnicity, an indication of their preference to not disclose ethnicity-related sensitive information. ConclusionsWe have shown how a publicly available voter database can be used to explore how self-reported ethnic attributes are modified by individual voters over time, and how the prevalence of such changes is influenced by political events such as presidential elections.

Mortality in adolescents receiving special education and social care provision: A population-level cohort study in England

BackgroundOver a third of children in England receive either special educational need (SEN) provision/children’s social care (CSC) support at least once during school. We aimed to describe all-cause and adversity-related mortality for adolescents who received SEN or CSC provision in England. ApproachWe used linked data from hospital admissions, death registrations, social care and education in the ECHILD database to follow all adolescents in state schools from age 13-years between 2009/10-2014/15 until death or 2020. Adolescents were grouped according to provision ever recorded before age 14: None, SEN only, CSC only or CSC and SEN. We estimated all-cause and adversity-related mortality in children with SEN/CSC/both compared to peers. ResultsThe cohort comprised 3,381,502 children (51% boys), of whom 30.1% (n=1,017,670, 62% boys) received SEN only, 4.2% (n=143,430, 36% boys) received CSC only and 8.7% (n=293,310, 57% boys) received SEN and CSC. In ten-year follow up, 6,590 deaths occurred (66% in boys). Mortality rates were 5.4 times higher for adolescents receiving both SEN and CSC, 2.4 times higher for CSC only, and 1.7 times higher for SEN only compared to peers. Rates of adversity-related deaths were highest for boys receiving SEN and CSC compared to peers. Conclusions &amp; Implications8-in-1000 adolescents who received both SEN and CSC before age 13 died by age 23 years, far more often than their peers. Policies need to consider support for young people with additional educational and social care needs as they leave school and transition to adulthood.

Potentially burdensome care at the end-of-life for people who had a death from cancer: A retrospective population-level cohort study

ObjectivesTo examine factors associated with indicators of potentially burdensome care provided in hospital, and use of hospital services in the last 12 months of life for people who had a death from cancer. ApproachA population-based retrospective cohort study of people aged ≥20 years with a cancer-related cause of death during 2014-2019 in New South Wales, Australia using linked hospital, cancer registry and mortality records. Ten indicators of potentially burdensome care were examined. Multinominal logistic regression examined predictors of a composite measure of potentially burdensome care, derived by summing 4 indicators: &gt;1 ED presentation; &gt;1 hospital admission; ≥1 ICU admission within 30 days of death; died in acute care (scored as 0, 1 ≥2). ResultsOf the 80,005 cancer-related deaths, 69.1% had none, 20.0% had 1 indicator, and 10.9% had ≥2 indicators of potentially burdensome care. Compared to having no indicators of potentially burdensome care, people who smoked, lived in rural areas, were most socially economically disadvantaged, and had their last admission in a private hospital were more likely to experience potentially burdensome care. Older people (≥55 years), females, people with 1 or ≥2 Charlson comorbidities, people with neurological cancers, and people who died in 2018-2019 were less likely to experience potentially burdensome care. Conclusions and implicationsThis study shows the challenge of delivering health services at end-of-life. Opportunities to address potentially burdensome EOLC could involve taking a person-centric approach to integrate oncology and palliative care around individual needs and preferences.

Characteristics and Rates of Preterm Births During the COVID-19 Pandemic in Germany

Population-based analyses provided divergent data on the changes in preterm birth rates during the COVID-19 pandemic, and there is a gap of knowledge on the variations in birth characteristics. To study changes in perinatal care, causes of preterm delivery, and very preterm (VPT; defined as <32 weeks' gestation) birth rates before and during the COVID-19 pandemic. This population-level cohort study used data from the quality assurance registry, which covers all births in Hesse, Germany. Deliveries during the COVID-19 pandemic (2020) were compared with the corresponding grouped prepandemic time intervals (2017 to 2019). Analyses were executed between August 2023 and July 2024. Analyses were directed to study differences in preterm births before and during 3 pandemic phases: first (March 14 to May 15, 2020) and second (October 19 to December 31, 2020) lockdowns and a period of less-vigorous restrictions between them (May 16 to October 18, 2020). Outcomes of interest were variations in preterm birth rates in the context of baseline characteristics and causes of preterm births during vs before the first year of the COVID-19 pandemic. From the total cohort of 184 827 births from 2017 to 2020, 719 stillbirths occurred and 184 108 infants were liveborn. Compared with the prepandemic period, medical care characteristics did not differ during the COVID-19 period. The odds of VPT births were lower during the pandemic period (odds ratio [OR], 0.87; 95% CI, 0.79-0.95) compared with the prepandemic period, with the greatest reduction observed during the second lockdown period (OR, 0.69; 95% CI, 0.55-0.84). Reduction in VPT births was attributed to fewer births in pregnancies among individuals with a history of serious disease (OR, 0.64; 95% CI, 0.50-0.83), pathologic cardiotocography (OR, 0.66; 95% CI, 0.53-0.82), and intrauterine infection (OR, 0.82; 95% CI, 0.72-0.92) while incidences of history of preterm birth, multiple pregnancies, serious or severe psychological distress, and preeclampsia, eclampsia, or hemolysis, elevated liver enzymes, and low platelet count syndrome as cause for preterm delivery remained unchanged. In this population-based cohort study on the COVID-19 pandemic and preterm birth rates, the duration of exposure to mitigation measures during pregnancy was associated with accelerated reductions in preterm births. The findings of lower rates of baseline risks and causes of preterm deliveries support efforts to intensify health care prevention programs during pregnancy to reduce the preterm birth burden. These findings of this study put particular focus on hygiene measures to reduce the rate of deliveries for intrauterine infection and highlight the potential of expanding strategies to the different risks and causes of preterm delivery.

A population-based repeated cross-sectional study using administrative health data to examine the impact of the COVID-19 pandemic on mental wellness in citizens of the Métis Nation of Ontario

Objective and ApproachThe COVID-19 pandemic led to unprecedented levels of mental unwellness and yet there are no reports to date that share Métis-specific data. Our study examined changes in patterns of mental and addictions-related (MHA) outpatient health service utilization using population-based data on Métis Nation of Ontario (MNO) citizens before and during the COVID-19 pandemic. Administrative health data in Ontario, Canada between 2017 and 2022 was linked with the MNO's Citizenship Registry (2022) under an existing Data Governance and Sharing Agreement. Monthly rates of MHA outpatient visits were compared between the pre-COVID-19 period (March 2017 to February 2020) and post-COVID-19 onset (March 2020 to December 2022), and rate ratios comparing observed and expected rates were derived using Poisson generalized estimating equations. Stratifications by age and sex were examined. Results and ConclusionAmong 28,400 MNO citizens (50.3% male; median age 44 years; 28.3% living rurally), the average monthly rate of MHA outpatient visits was 47.4 per 1000 population pre-COVID-19. During the COVID-19 pandemic, the observed MHA outpatient visit rates were 13% higher than expected (RR=1.13; 95% CI: 1.02-1.26). MHA outpatient visits were higher in females compared to males and MNO citizens aged 30 to 64 years versus older or younger citizens. Implications This study is the first to use population-level study to examine MHA health service use in Métis people. High-quality, contemporary data on the mental health outcomes of MNO citizens is crucial to inform MNO’s Mental Health and Addictions programming, resource allocation and emergency preparedness.

Registry study of cardiovascular death in Sweden 2013–2019: Home as place of death and specialized palliative care are the preserve of a minority

BackgroundPalliative care needs in patients with cardiovascular diseases (CVD) are expected to increase. For the planning of equitable palliative care, it is important to understand where people with CVD die. The aim was to examine trends in place of death, associated factors including utilization of specialized palliative services, and to what extent longitudinal development is influenced by national policy. MethodsA population-level registry study of place of death for adults deceased due to CVD (n = 209 671) in Sweden 2013–2019. Linear regression analysis was applied. ResultsThe predominant place of death was nursing home (39.1 %) and hospital (37.6 %), followed by home (22.0 %). From 2013 to 2019 home deaths increased by 2.8 % and hospital deaths decreased by 3.0 %. An overall downward trend was found for dying in hospital compared to dying at home. With variations, this trend was seen in all healthcare regions and for all CVD types, except Stockholm and cerebrovascular disease, with no significant trend. Overall, but with cross-regional variations, 2.1 % utilized specialized palliative services, while 94.2 % had potential palliative care needs. Other variables significantly influencing the trend were age and having had an unplanned healthcare visit. ConclusionDespite a slight positive trend, only a minority of people with CVD die in their own home. Regional variations in place of death and the low and varied utilization of specialized palliative services indicate inequity in access to palliative care. Hence, the impact of current national policies is questionable and calls for strengthening through inclusion of early palliative care in specific CVD policies.

50136 Lichen planus is associated with other autoimmune conditions: A retrospective population-level study

50136 Lichen planus is associated with other autoimmune conditions: A retrospective population-level study

Trends in viral hepatitis liver-related morbidity and mortality in New South Wales, Australia

Monitoring hepatitis B virus (HBV) and hepatitis C virus (HCV) liver-related morbidity and mortality is key to evaluate progress towards elimination targets. HBV and HCV notifications in NSW, Australia (1995-2022) were linked to hospital and mortality records. Temporal trends in decompensated cirrhosis (DC), hepatocellular carcinoma (HCC), and mortality were evaluated among people notified for HBV and HCV. Segmented Poisson regression models were used to assess the impact of the viral hepatitis elimination era (1 January 2015-31 December 2022) on advanced liver disease and mortality. During 1995-2022, there were 64,865 people with an HBV notification and 112,277 people with an HCV notification in NSW. Between 2002 and 2022, there were significant reductions in age-adjusted HBV- and HCV-related DC, HCC, and liver-related mortality. Among those with HBV, age-standardised incidence per 1000 person-years (py) in 2002, 2015, and 2022 was 3.08, 1.47, and 1.16 for DC (p<0.001); 2.97, 1.45, and 0.75 for HCC (p<0.001); and 2.84, 1.93, and 1.40 for liver-related mortality (p<0.001). Among those with HCV, age-standardised incidence per 1000 py in 2002, 2015, and 2022, was 5.53, 4.57, and 2.31 for DC (p<0.001); 2.22, 2.59, and 1.87 for HCC (p<0.001); and 3.89, 4.73, and 3.16 for liver-related mortality (p<0.001). In 2022, absolute liver-related mortality per 100,000 population was 0.95 for HBV and 3.56 for HCV. In adjusted analyses, older age, comorbidity, and a history of alcohol use disorder were associated with increased liver-related mortality among those with HBV and HCV. This population-level study demonstrated declining risks of DC, HCC, and mortality, with HBV-related declines commencing well before elimination era while HCV-related declines were mostly during elimination era. Population liver mortality indicates elimination target achieved for combined viral hepatitis and HBV, but not HCV. The Kirby Institute, UNSW Sydney, and New South Wales Ministry of Health, Australia.

Association between antibiotic usage during infancy and asthma incidence among children: a population-level ecological study in British Columbia, Canada.

This study follows published associations in BC to 2014 (updated in 2019) to model the predicted incidence of asthma in BC children attributable to antibiotic use within the context of reduced antibiotic use and increased breastfeeding in BC infants from 2000 to 2019. A population-based ecological study was conducted in BC from 2000 to 2019, using outpatient antibiotic prescription data from BC PharmaNet and asthma diagnoses from the Chronic Disease Registry. Breastfeeding estimates were calculated using the Canadian Community Health Survey (CCHS). Population attributable risk (PAR) was calculated using a blended relative risk (RR) of asthma in antibiotic-exposed children who were and were not breastfed. PAR was used to calculate predicted vs. actual asthma incidence in 2019. Negative binomial regression was used to estimate the association between the average antibiotic prescription rate in infants under 1 and asthma incidence in 1-4 year olds, stratified by periods between 2000-2014 and 2015-2019. In BC, antibiotic prescribing decreased by 77% in infants under 1 and asthma incidence decreased by 41% in children 1-4 years from 2000 to 2019. BC breastfeeding rates increased from 46% in the 2005 CCHS to 71% in the 2017/18 CCHS. After calculating the PAR using a blended RR, the predicted asthma incidence in 2019 was 18.8/1,000 population. This was comparable to the observed asthma incidence in children 1-4 years of 16.6/1,000 population in 2019. During 2000-2014, adjusted incidence risk ratio (aIRR) for children under Quintile 5 of average antibiotic prescribing was 1.75 (95% CI: 1.63-1.88, P < 0.0001) times higher than that for Quintile 1. However, between 2015 and 2019, this association weakened (as expected because of increasing prevalence of breastfeeding), with the expected asthma incidence for Quintile 5 only 11% (aIRR 1.11, 95% CI: 0.78-1.57) higher than for Quintile 1. We identified that over the past 20 years, antibiotic exposure in infants under 1 and asthma incidence in children 1-4 years has decreased significantly. Decreasing antibiotic exposure and increasing breastfeeding (which further mitigates risk associated with antibiotics) are of sufficient scale to explain much of this population trend. Changes in environmental, social and other exposures remain relevant to this complicated etiological pathway.

Genomic implications of the repeated shift to self-fertilization across a species' geographic distribution.

The ability to self-fertilize often varies among closely related hermaphroditic plant species, though, variation can also exist within species. In the North American Arabidopsis lyrata, the shift from self-incompatibility (SI) to selfing established in multiple regions independently, mostly since recent postglacial range expansion. This has made the species an ideal model for the investigation of the genomic underpinnings of the breakdown of SI and its population genetic consequences. By comparing nearby selfing and outcrossing populations across the entire species' geographic distribution, we investigated variation at the self-incompatibility (S-)locus and across the genome. Furthermore, a diallel crossing experiment on one mixed-mating population was performed to gain insight in the genetics of mating system variation. We confirmed that the breakdown of SI had evolved in several S-locus backgrounds. The diallel suggested the involvement of binuclearly expressed parental genes with dominance relations. Though, the population-level genome-wide association study did not single out clear-cut candidate genes but several regions with one near the S-locus. On the implication side, selfing as compared to outcrossing populations had less than half of the genomic diversity, while the number of runs of homozygosity and their length scaled with the degree of inbreeding. The results highlight that mating system shifts to selfing, its genetic underpinning and the likely negative genomic consequences for evolutionary potential can be strongly interlinked with past range dynamics.

Hidradenitis suppurativa is associated with inflammatory arthritis, systemic lupus erythematosus, and other autoimmune diseases: A retrospective population-level study

Hidradenitis suppurativa is associated with inflammatory arthritis, systemic lupus erythematosus, and other autoimmune diseases: A retrospective population-level study

Integrating youth participatory action research and health communication to inform youth and young adult covid-19 vaccine communication research.

COVID-19 vaccination rates remain lower among adolescents compared with adults. Youth participatory action research (YPAR) offers opportunities to inform youth vaccine communication at the local and population level. However, few studies have integrated systematic health communication research with YPAR. In the current study, a diverse team of paid high school interns, undergraduate student mentors and communication researchers in West Philadelphia YPAR programs developed a theory-informed communication survey to measure teen COVID-19 vaccine beliefs, information sources and behavior. The survey was distributed locally and informed youth-created vaccine campaign messages. In addition, YPAR-derived survey measures complimented a qualitative online elicitation survey with US young adults. Responses were coded using inductive content analysis, informing measures for a subsequent population-level study of young adults. This research followed protocols approved by an Institutional Review Board. Applying a YPAR framework elevated youth voices in the study development process. Communication theory and methods aided the development of survey studies to advance both local YPAR program objectives and population-level research. Future implications are discussed.