Do hospitals have a higher mortality rate on weekend admissions? An observational study to analyse weekend effect on urgent admissions to hospitals in Catalonia.

BACKGROUND: 'Weekend effect' is a term used to describe the increased mortality associated with weekend emergency admissions to hospital, in contrast with admission on weekdays. The objective of the present study is to determine whether the weekend effect is present in hospitals in Catalonia. METHODS: We analysed all urgent admissions in Catalonia in 2018, for a group of pathologies. Two groups were defined (those admitted on a weekday and those admitted on a weekend). We obtained mortality at 3, 7, 15 and 30 days, and applied a proportions test to both groups. Additionally, we used Cox's regression for mortality at 30 days, using the admission on a weekend as the exposition, adjusting by socioeconomic and clinical variables. We used the hospital discharge database and the Central Registry of the Insured Population. RESULTS: 72 427 admissions for the selected pathologies during 2018 were found. No statistically significant differences in mortality at 30 days (p=0.524) or at 15 days (p=0.119) according to the day of admission were observed. However, significant differences were found in mortality at 7 days (p=0.025) and at 3 days (p=0.002). The hazard rate associated with the weekend was 1.13 (95% CI: 1.04 to 1.23). By contrast, the adjusted HR of the weekend interaction with time was 0.99 (95% CI: 0.99 to 1.00). CONCLUSIONS: There is a weekend effect, but it is not constant in time. This could suggest the existence of dysfunctions in the quality of care during the weekend.

Determinants of the number of days people in the general population spent at home during end-of-life: Results from a population-based cohort analysis.

BACKGROUND: The number of days spent at home in the last six months of life has been proposed as a comprehensive indicator of high-value patient-centered care; however, information regarding the determinants of this outcome is scarce, particularly among the general population. We investigated the determinants of spending time at home within the six months preceding death. METHODS: Population-based, retrospective analysis of administrative databases of the Catalan government. The analysis included adult (≥18 years) individuals who died in Catalonia (North-east Spain) in 2017 and met the McNamara criteria for palliative care. The primary outcome was the number of days spent at home within the last 180 days of life. Other variables included the cause of death, demographic characteristics, and socioeconomic status, stratified as very low, low, mid, and high level. RESULTS: The analysis included 40,137 individuals (19,510 women; 20,627 men), who spent a median of 140 days (IQR 16-171) at home within the six months preceding death (women 140 [16-171]; men 150 [100-171]). Female gender was an independent factor of staying fewer days at home (OR 0.80 [95% CI 0.77-0.82]; p<0.001). Higher socioeconomic levels were significantly associated with an increasing number of days at home in both genders: among women, ORs of the low, middle, and high levels were 1.09 (0.97-1.22), 1.54 (1.36-1.75), and 2.52 (1.69-3.75) (p<0.001), respectively; the corresponding ORs among men were 1.27 (1.12-1.43), 1.56 (1.38-1.77), 2.82 (2.04-3.88) (p<0.001). The presence of dementia was a strong predictor of spending less time at home in women (0.41 (0.38-0.43); p<0.001) and men (0.45 (0.41-0.48); p<0.001). CONCLUSIONS: Our results suggest that end-of-life care is associated with gender and socioeconomic inequalities; women and individuals with lower socioeconomic status spend less time at home within the last 180 days of life.

Use of fourth-generation rapid combined antigen and antibody diagnostic tests for the detection of acute HIV infection in a community centre for men who have sex with men, between 2016 and 2019.

OBJECTIVE: To assess the use of fourth-generation rapid diagnostic tests in identifying acute infection of Human Immunodeficiency Virus (HIV). METHODS: BCN Checkpoint promotes sexual health among men who have sex with men (MSM), with a focus on diagnosing HIV early, initiating combined antiretroviral treatment (cART) promptly, and recommending regular repeat testing for those who have tested negative. This cross-sectional study included all test results obtained at the centre between 25 March 2016 and 24 March 2019. The Alere™ HIV Combo (now rebranded to Determine™ HIV Ultra, from Abbott) was used to detect p24 antigen (p24 Ag) and/or immunoglobulin M (IgM) and G (IgG) antibodies to HIV-1/HIV-2 (HIV Ab). Rapid polymerase chain reaction (PCR) confirmatory testing and Western blot (WB) were performed for clients with a positive rapid test result. Confirmed HIV cases were promptly referred to the HIV unit for care and cART prescription. RESULTS: A total of 12,961 clients attended BCN Checkpoint during the study and 27,298 rapid tests were performed. 450 tests were found to be reactive, of which 430 confirmed as HIV-positive, representing a prevalence of 3.32%. Four confirmed cases (0.93%) were detected as "p24 Ag only", nine (2.09%) as "both p24 and HIV Ab" and 417 (96.98%) as "HIV Ab only". The "p24 Ag only" group had a 1-log higher viral load than the other groups and initiated treatment on the following working day. Overall, there were 20 false-positive results (0.07% and 4.44% of total and reactive tests, respectively), of which 10 positive for "p24 Ag only" and 10 for "HIV Ab only". CONCLUSIONS: Four Acute HIV Infections (AHI), with very high viral loads, have been detected with the "p24 Ag only" while the HIV Ab were still absent. Referral to the HIV unit and initiation of cART on the following working day contributed to improving persons' health and to reduce HIV transmission chain.

Socioeconomic inequalities in 29 childhood diseases: evidence from a 1,500,000 children population retrospective study.

BACKGROUND: Socioeconomic position (SEP) powerfully affects health status in the childhood population. However, the knowledge of which diseases are more affected by SEP and whose outcomes could be improved by having a more equitable society remains uncertain on a population basis. METHODS: We measured socioeconomic and gender inequalities in the pre-COVID-19 era for 29 diseases in the entire childhood population in Catalonia to identify which diseases are most impacted by inequalities. This population-based study included 1,449,816 children under 15 years old from 2014 to 2017 (48.52% girls) and each of their registered diagnoses within the Catalonia National Health System. We calculated frequency measures by SEP and their sex ratios for each disease. We estimated four regression-based inequality measures: slope index of inequality, relative index of inequality (RII), absolute population-attributable fraction, and population-attributable fraction. RESULTS: Twenty-five of the 29 diseases examined showed SEP inequalities. The diseases with the greatest inequalities in both sexes were tuberculosis, obesity, adjustment and anxiety disorders, essential hypertension, poisoning, short gestation, low birth weight, foetal growth retardation and intrauterine hypoxia and birth asphyxia and trauma (RII ≥ 2.0); only food allergy showed the opposite pattern (RII < 1.0). Overall, 80,188 (7.80%) of the disease events in boys and 74,921 (8.88%) in girls would be avoided if all children had the same disease rate as those in the medium-high SEP group, with tuberculosis, intrauterine hypoxia and birth asphyxia and trauma, obesity, and short gestation, low birth weight, foetal growth retardation being those that could be reduced the most in relative terms, and dermatitis, injuries, acute bronquitis, and being overweight those that could be reduced the most in absolute terms. Girls present higher RII than boys for respiratory allergy, asthma, dermatitis, being overweight, and obesity (p < 0.05). In contrast, boys showed higher RII compared to girls only in congenital anomalies (p < 0.05). CONCLUSIONS: Socioeconomic and gender inequalities are widely present in childhood health. This indicates that SEP plays a common role in their development although it varies in magnitude according to each disease. It is also a phenomenon that comprises all SEP groups in society. Action needs to be taken to ensure a fairer start in life in terms of health.

Frequency of health-care service use and severity of illness in undocumented migrants in Catalonia, Spain: a population-based, cross-sectional study.

BACKGROUND: In Spain, legislation was passed in 2012 excluding undocumented migrants from the public health-care system. Catalonia was one of the Spanish regions that did not implement this legislation, and continued to guarantee access to health care to the whole population. We aimed to analyse health-care use and health status among undocumented migrants in Catalonia, and compare health-care use and health status with legal residents classified according to their socioeconomic position (SEP). METHODS: We did a population-based, cross-sectional study, with administrative individual data. The study included the resident population in Catalonia, Spain, in 2017, aged younger than 65 years and with a maximum annual income of less than €18 000 per year, and classified into three socioeconomic (SEP) groups-low SEP, very low SEP, and undocumented migrants. Indicators regarding health-care service use (primary care, emergency care, mental health care, acute care), drug prescriptions, and selected chronic and infectious diseases were analysed. FINDINGS: Between Jan 1 and Dec 31, 2017, 4 071 988 residents of Catalonia were included in this study; undocumented migrants represented 2·8% (n=113 450) of this population. Of all undocumented migrants, 25 942 (61·0%) female participants aged 15-64 years and 19 819 (46·0%) male participants aged 15-64 years attended primary health-care centres: these rates were lower than in individuals with a very low SEP (84·8% in female participants and 72·1% in male participants). Hospital admission rates among male participants aged 15-64 years in the very low SEP group were more than three times as high as in undocumented migrants (111·6 vs 35·7). The highest tuberculosis rate was found in undocumented male migrants (incidence rate 4·35 [95% CI 3·55-5·16]). INTERPRETATION: Undocumented migrants made less use of health-care services than those in the low and very low SEP groups, but for some infectious diseases, incidence was higher in undocumented migrants. These results constitute an additional argument to support the maintenance of universal health coverage for all citizens. FUNDING: None.

Advance directives and real-world end-of-life clinical practice: a case-control study.

BACKGROUND: Advance directives (ADs) have been legally regulated to promote autonomy over health decisions among patients who later lose decision-making capacity. AIMS AND OBJECTIVES: To analyse the differences in clinical practice at end of life among people who had completed an AD versus those who had not. METHODS: Retrospective case-control study (1:2), matched by age, sex, year, cause of death and region of residence. The data sources used were the ADs registry, central registry of insured persons, hospital discharge, pharmacy and billing databases, and the mortality registry. Conditional logistic regression models (crude and adjusted by socioeconomic level) were performed. The outcome variable was the frequency of medical procedures performed during the last year of life. RESULTS: 1723 people with ADs who died in Catalonia during 2014-2015 were matched with 3446 dead controls (without ADs). Thoracentesis was the procedure with the greatest reduction among women with an AD (adjusted OR (ORadj) 0.54, 95% CI: 0.32 to 0.89) in conjunction with artificial nutrition (ORadj 0.54, 95% CI: 0.31 to 0.95). Intubation was the procedure with the greatest reduction (ORadj 0.56, 95% CI: 0.33 to 0.94) among men. Slight differences could be seen in the case of cancer deaths. There were no relevant differences when adjusting by socioeconomic level. CONCLUSIONS: ADs are an effective tool to adjust the realisation of some procedures at end of life. These results can help better plan for the treatment of patients with ADs, as well as increase the awareness among clinical personnel, families and the general population.

Relationship between parents' mental disorders and socioeconomic status and offspring's psychopathology: A cross-sectional study.

Mental disorders (MD) are one of the main causes of the disease burden worldwide. Associations between socioeconomic status (SES) and presence of MD in parents have been related with increased odds of MD in offspring. However, there is a lack of population-based research in this field. The aim of the present study was to examine together the relationship between the presence of MD in children, and the SES and presence of MD in their parents, in a whole of population data. A gender approach was undertaken aiming to discern how these variables influence children's mental health when related with the father and the mother. Using administrative individual data from the National Health System, a retrospective cross-sectional study was conducted. The entire children population aged 6 to 15 resident in Catalonia in 2017 was examined. A logistic regression model was performed. Low SES was associated with increased odds of children's MD. Offspring of a parent with MD were at more risk of presenting MD than offspring of parents without these problems. Although these associations were consistent for both boys and girls when looking at the father's or mother's SES and MDs, the mother's SES and MDs showed a higher association with the offspring's MDs than the father's. Lowest associations, found for boys when looking at the father's SES and MDs, were: OR of 1.21, 95%CI 1.16 to 1.27 for lowest SES, and OR of 1.66, 95%CI 1.61 to 1.70 for parental MDs. Children's familiar environment, which includes SES and mental health of parents, plays an important role in their mental health. Socially constructed gender roles interfere with SES and parent's MD. These findings support the relevance of examining MD and its risk factors within a gender approach.

Comorbidity patterns and socioeconomic inequalities in children under 15 with medical complexity: a population-based study.

BACKGROUND: Children with medical complexity (CMC) denotes the profile of a child with diverse acute and chronic conditions, making intensive use of the healthcare services and with special health and social needs. Previous studies show that CMC are also affected by the socioeconomic position (SEP) of their family. The aim of this study is to describe the pathologic patterns of CMC and their socioeconomic inequalities in order to better manage their needs, plan healthcare services accordingly, and improve the care models in place. METHODS: Cross-sectional study with latent class analysis (LCA) of the CMC population under the age of 15 in Catalonia in 2016, using administrative data. LCA was used to define multimorbidity classes based on the presence/absence of 57 conditions. All individuals were assigned to a best-fit class. Each comorbidity class was described and its association with SEP tested. The Adjusted Morbidity Groups classification system (Catalan acronym GMA) was used to identify the CMC. The main outcome measures were SEP, GMA score, sex, and age distribution, in both populations (CMC and non-CMC) and in each of the classes identified. RESULTS: 71% of the CMC population had at least one parent with no employment or an annual income of less than €18,000. Four comorbidity classes were identified in the CMC: oncology (36.0%), neurodevelopment (13.7%), congenital and perinatal (19.8%), and respiratory (30.5%). SEP associations were: oncology OR 1.9 in boys and 2.0 in girls; neurodevelopment OR 2.3 in boys and 1.8 in girls; congenital and perinatal OR 1.7 in boys and 2.1 in girls; and respiratory OR 2.0 in boys and 2.0 in girls. CONCLUSIONS: Our findings show the existence of four different patterns of comorbidities in CMC and a significantly high proportion of lower SEP children in all classes. These results could benefit CMC management by creating more efficient multidisciplinary medical teams according to each comorbidity class and a holistic perspective taking into account its socioeconomic vulnerability.

Falling HIV incidence in a community clinic cohort of men who have sex with men and transgender women in Barcelona, Spain.

In Barcelona, Spain prior to 2006, HIV testing was mostly limited to formal healthcare facilities with no incidence data reported. A community-based organization (BCN Checkpoint) was established to increase HIV testing in a peer-led community location to generate incidence data in men who have sex with men and transgender women. Three community engagement interventions were conducted between 2009 and 2017 as follows: 2009-2011 (peer-led point-of-care testing for HIV), 2012-2014 (12-monthly HIV testing with an emphasis on testing in partnerships), 2015-2017 (three-monthly HIV testing with rapid referral for antiretroviral initiation). Between 2009 and 2017 a predominantly cisgender male (99.4%) and Spanish national (62.4%) population with mean age of 34.8 years had 49,630 visits. Mean visit number increased from 1.69 in the first to 2.07 in the last three-year period. HIV incidence fell from 4.17 (95% confidence interval [CI]: 3.53-4.93) per 100 person-years in 2009-2011 to 1.57 (95% CI: 1.30-1.89) per 100 person-years in 2015-2017. This represents a 62% reduction (incidence rate ratio: 0.38, 95% CI: 0.29-0.48) between the first and third study period (p < 0.001). These early interventions may have contributed to the reduction seen in HIV incidence in this cohort.

Caesarean section trends in Catalonia between 2013 and 2017 based on the Robson classification system: A cross-sectional study.

INTRODUCTION: In Catalonia caesarean rates have always been analysed as a single percentage. The objective is to estimate caesarean section rates using the Robson classification in publicly funded hospitals in Catalonia between 2013 and 2017, considering sociodemographic, institutional and obstetric characteristics. MATERIALS AND METHODS: Cross-sectional population-based study in Catalonia including all women delivering within publicly funded hospitals between 2013-2017 (n = 210 020). The modified Robson classification distribution was estimated, the caesarean rate and the overall contribution, analysed for each year, and by confounders, through logistic regression models. RESULTS: CS rates decreased steadily between 2013 and 2017 in Catalonia within publicly funded hospitals from 24.3% to 22.8% (cOR 0.92, 95% CI; 0.89 to 0.95). Once adjusted for changes in sociodemographic, institutional and obstetric characteristics the observed decline was even more pronounced (aOR 0.87, 95% CI; 0.84 to 0.90). Within the different groups of Robson once adjusted for confounders, groups 1+2 (aOR 0.88, 95% CI; 0.83 to 0.93), 3+4 (aOR 0.83, 95% CI; 0.78 to 0.89) and 10 (aOR 0.78, 95% CI; 0.68 to 0.90) presented a reduction in caesarean section rates, whereas group 5 showed no significant decrease (aOR 0.95, 95% CI; 0.87 to 1.03%). CONCLUSIONS: The decrease in caesarean section rates in Catalonia is more pronounced when adjusted for known confounders, suggesting retrospective overutilization of caesarean section and percentages of (in)adequacy in the past. In any case, it remains above the recommended by experts. Further efforts should be made to achieve optimum rates, including improvement on obstetric data collection.

Effect modification of FADS2 polymorphisms on the association between breastfeeding and intelligence: results from a collaborative meta-analysis.

BACKGROUND: Accumulating evidence suggests that breastfeeding benefits children's intelligence, possibly due to long-chain polyunsaturated fatty acids (LC-PUFAs) present in breast milk. Under a nutritional adequacy hypothesis, an interaction between breastfeeding and genetic variants associated with endogenous LC-PUFAs synthesis might be expected. However, the literature on this topic is controversial. METHODS: We investigated this gene × environment interaction through a collaborative effort. The primary analysis involved >12 000 individuals and used ever breastfeeding, FADS2 polymorphisms rs174575 and rs1535 coded assuming a recessive effect of the G allele, and intelligence quotient (IQ) in Z scores. RESULTS: There was no strong evidence of interaction, with pooled covariate-adjusted interaction coefficients (i.e. difference between genetic groups of the difference in IQ Z scores comparing ever with never breastfed individuals) of 0.12[(95% confidence interval (CI): -0.19; 0.43] and 0.06 (95% CI: -0.16; 0.27) for the rs174575 and rs1535 variants, respectively. Secondary analyses corroborated these results. In studies with ≥5.85 and <5.85 months of breastfeeding duration, pooled estimates for the rs174575 variant were 0.50 (95% CI: -0.06; 1.06) and 0.14 (95% CI: -0.10; 0.38), respectively, and 0.27 (95% CI: -0.28; 0.82) and -0.01 (95% CI: -0.19; 0.16) for the rs1535 variant. CONCLUSIONS: Our findings did not support an interaction between ever breastfeeding and FADS2 polymorphisms. However, subgroup analysis suggested that breastfeeding may supply LC-PUFAs requirements for cognitive development if breastfeeding lasts for some (currently unknown) time. Future studies in large individual-level datasets would allow properly powered subgroup analyses and further improve our understanding on the breastfeeding × FADS2 interaction.

Thyroid Function in Early Pregnancy, Child IQ, and Autistic Traits: A Meta-Analysis of Individual Participant Data.

Context: Low maternal free T4 (FT4) has been associated with poor child neurodevelopment in some single-center studies. Evidence remains scarce for the potential adverse effects of high FT4 and whether associations differ in countries with different iodine status. Objective: To assess the association of maternal thyroid function in early pregnancy with child neurodevelopment in countries with a different iodine status. Design, Setting, and Participants: Meta-analysis of individual participant data from 9036 mother-child pairs from three prospective population-based birth cohorts: INMA [Infancia y Medio Ambiente (Environment and Childhood project) (Spain)], Generation R (Netherlands), and ALSPAC (Avon Longitudinal Study of Parents and Children, United Kingdom). The exclusion criteria were multiple pregnancies, fertility treatments, thyroid-interfering medication usage, and known thyroid disease. Main Outcomes: Child nonverbal IQ at 5 to 8 years of age, verbal IQ at 1.5 to 8 years of age, and autistic traits within the clinical range at 5 to 8 years of age. Results: FT4 <2.5th percentile was associated with a 3.9-point (95% CI, -5.7 to -2.2) lower nonverbal IQ and a 2.1-point (95% CI, -4.0 to -0.1) lower verbal IQ. A suggestive association of hypothyroxinemia with a greater risk of autistic traits was observed. FT4 >97.5th percentile was associated with a 1.9-fold (95% CI, 1.0 to 3.4) greater risk of autistic traits. No independent associations were found with TSH. Conclusions: Low maternal FT4 was consistently associated with a lower IQ across the cohorts. Further studies are needed to replicate the findings of autistic traits and investigate the potential modifying role of maternal iodine status. FT4 seems a reliable marker of fetal thyroid state in early pregnancy, regardless of the type of immunoassay.

Spatial and temporal variability of personal environmental exposure to radio frequency electromagnetic fields in children in Europe.

BACKGROUND: Exposure to radiofrequency electromagnetic fields (RF-EMF) has rapidly increased and little is known about exposure levels in children. This study describes personal RF-EMF environmental exposure levels from handheld devices and fixed site transmitters in European children, the determinants of this, and the day-to-day and year-to-year repeatability of these exposure levels. METHODS: Personal environmental RF-EMF exposure (µW/m2, power flux density) was measured in 529 children (ages 8-18 years) in Denmark, the Netherlands, Slovenia, Switzerland, and Spain using personal portable exposure meters for a period of up to three days between 2014 and 2016, and repeated in a subsample of 28 children one year later. The meters captured 16 frequency bands every 4 s and incorporated a GPS. Activity diaries and questionnaires were used to collect children's location, use of handheld devices, and presence of indoor RF-EMF sources. Six general frequency bands were defined: total, digital enhanced cordless telecommunications (DECT), television and radio antennas (broadcast), mobile phones (uplink), mobile phone base stations (downlink), and Wireless Fidelity (WiFi). We used adjusted mixed effects models with region random effects to estimate associations of handheld device use habits and indoor RF-EMF sources with personal RF-EMF exposure. Day-to-day and year-to-year repeatability of personal RF-EMF exposure were calculated through intraclass correlations (ICC). RESULTS: Median total personal RF-EMF exposure was 75.5 µW/m2. Downlink was the largest contributor to total exposure (median: 27.2 µW/m2) followed by broadcast (9.9 µW/m2). Exposure from uplink (4.7 µW/m2) was lower. WiFi and DECT contributed very little to exposure levels. Exposure was higher during day (94.2 µW/m2) than night (23.0 µW/m2), and slightly higher during weekends than weekdays, although varying across regions. Median exposures were highest while children were outside (157.0 µW/m2) or traveling (171.3 µW/m2), and much lower at home (33.0 µW/m2) or in school (35.1 µW/m2). Children living in urban environments had higher exposure than children in rural environments. Older children and users of mobile phones had higher uplink exposure but not total exposure, compared to younger children and those that did not use mobile phones. Day-to-day repeatability was moderate to high for most of the general frequency bands (ICCs between 0.43 and 0.85), as well as for total, broadcast, and downlink for the year-to-year repeatability (ICCs between 0.49 and 0.80) in a small subsample. CONCLUSION: The largest contributors to total personal environmental RF-EMF exposure were downlink and broadcast, and these exposures showed high repeatability. Urbanicity was the most important determinant of total exposure and mobile phone use was the most important determinant of uplink exposure. It is important to continue evaluating RF-EMF exposure in children as device use habits, exposure levels, and main contributing sources may change.

Air Pollution Exposure During Fetal Life, Brain Morphology, and Cognitive Function in School-Age Children.

BACKGROUND: Air pollution exposure during fetal life has been related to impaired child neurodevelopment, but it is unclear if brain structural alterations underlie this association. The authors assessed whether air pollution exposure during fetal life alters brain morphology and whether these alterations mediate the association between air pollution exposure during fetal life and cognitive function in school-age children. METHODS: We used data from a population-based birth cohort set up in Rotterdam, The Netherlands (2002-2006). Residential levels of air pollution during the entire fetal period were calculated using land-use regression models. Structural neuroimaging and cognitive function were performed at 6 to 10 years of age (n = 783). Models were adjusted for several socioeconomic and lifestyle characteristics. RESULTS: Mean fine particle levels were 20.2 µg/m3 (range, 16.8-28.1 µg/m3). Children exposed to higher particulate matter levels during fetal life had thinner cortex in several brain regions of both hemispheres (e.g., cerebral cortex of the precuneus region in the right hemisphere was 0.045 mm thinner (95% confidence interval, 0.028-0.062) for each 5-µg/m3 increase in fine particles). The reduced cerebral cortex in precuneus and rostral middle frontal regions partially mediated the association between exposure to fine particles and impaired inhibitory control. Air pollution exposure was not associated with global brain volumes. CONCLUSIONS: Exposure to fine particles during fetal life was related to child brain structural alterations of the cerebral cortex, and these alterations partially mediated the association between exposure to fine particles during fetal life and impaired child inhibitory control. Such cognitive impairment at early ages could have significant long-term consequences.

The Association between Lifelong Greenspace Exposure and 3-Dimensional Brain Magnetic Resonance Imaging in Barcelona Schoolchildren.

BACKGROUND: Proponents of the biophilia hypothesis believe that contact with nature, including green spaces, has a crucial role in brain development in children. Currently, however, we are not aware of evidence linking such exposure with potential effects on brain structure. OBJECTIVE: We determined whether lifelong exposure to residential surrounding greenness is associated with regional differences in brain volume based on 3-dimensional magnetic resonance imaging (3D MRI) among children attending primary school. METHODS: We performed a series of analyses using data from a subcohort of 253 Barcelona schoolchildren from the Brain Development and Air Pollution Ultrafine Particles in School Children (BREATHE) project. We averaged satellite-based normalized difference vegetation index (NDVI) across 100-m buffers around all residential addresses since birth to estimate each participant's lifelong exposure to residential surrounding greenness, and we used high-resolution 3D MRIs of brain anatomy to identify regional differences in voxel-wise brain volume associated with greenness exposure. In addition, we performed a supporting substudy to identify regional differences in brain volume associated with measures of working memory (d' from computerized n-back tests) and inattentiveness (hit reaction time standard error from the Attentional Network Task instrument) that were repeated four times over one year. We also performed a second supporting substudy to determine whether peak voxel tissue volumes in brain regions associated with residential greenness predicted cognitive function test scores. RESULTS: Lifelong exposure to greenness was positively associated with gray matter volume in the left and right prefrontal cortex and in the left premotor cortex and with white matter volume in the right prefrontal region, in the left premotor region, and in both cerebellar hemispheres. Some of these regions partly overlapped with regions associated with cognitive test scores (prefrontal cortex and cerebellar and premotor white matter), and peak volumes in these regions predicted better working memory and reduced inattentiveness. CONCLUSION: Our findings from a study population of urban schoolchildren in Barcelona require confirmation, but they suggest that being raised in greener neighborhoods may have beneficial effects on brain development and cognitive function. https://doi.org/10.1289/EHP1876.

Exposure to elemental composition of outdoor PM2.5 at birth and cognitive and psychomotor function in childhood in four European birth cohorts.

BACKGROUND: Little is known about developmental neurotoxicity of particulate matter composition. We aimed to investigate associations between exposure to elemental composition of outdoor PM2.5 at birth and cognitive and psychomotor functions in childhood. METHODS: We analyzed data from 4 European population-based birth cohorts in the Netherlands, Germany, Italy and Spain, with recruitment in 2000-2006. Elemental composition of PM2.5 measurements were performed in each region in 2008-2011 and land use regression models were used to predict concentrations at participants' residential addresses at birth. We selected 8 elements (copper, iron, potassium, nickel, sulfur, silicon, vanadium and zinc) and used principal component analysis to combine elements from the same sources. Cognitive (general, verbal, and non-verbal) and psychomotor (fine and gross) functions were assessed between 1 and 9years of age. Adjusted cohort-specific effect estimates were combined using random-effects meta-analysis. RESULTS: 7246 children were included in this analysis. Single element analysis resulted in negative association between estimated airborne iron and fine motor function (-1.25 points [95% CI -2.45 to -0.06] per 100ng/m3 increase of iron). Association between the motorized traffic component, derived from principal component analysis, and fine motor function was not significant (-0.29 points [95% CI -0.64 to 0.06] per unit increase). None of the elements were associated with gross motor function or cognitive function, although the latter estimates were predominantly negative. CONCLUSION: Our results suggest that iron, a highly prevalent element in motorized traffic pollution, may be a neurotoxic compound. This raises concern given the ubiquity of motorized traffic air pollution.

Lifelong Residential Exposure to Green Space and Attention: A Population-based Prospective Study.

BACKGROUND: Natural environments, including green spaces, may have beneficial impacts on brain development. However, longitudinal evidence of an association between long-term exposure to green spaces and cognitive development (including attention) in children is limited. OBJECTIVES: We evaluated the association between lifelong residential exposure to green space and attention during preschool and early primary school years. METHODS: This longitudinal study was based on data from two well-established population-based birth cohorts in Spain. We assessed lifelong exposure to residential surrounding greenness and tree cover as the average of satellite-based normalized difference vegetation index and vegetation continuous fields, respectively, surrounding the child's residential addresses at birth, 4-5 y, and 7 y. Attention was characterized using two computer-based tests: Conners' Kiddie Continuous Performance Test (K-CPT) at 4-5 y (n=888) and Attentional Network Task (ANT) at 7 y (n=987). We used adjusted mixed effects models with cohort random effects to estimate associations between exposure to greenness and attention at ages 4-5 and 7 y. RESULTS: Higher lifelong residential surrounding greenness was associated with fewer K-CPT omission errors and lower K-CPT hit reaction time-standard error (HRT-SE) at 4-5 y and lower ANT HRT-SE at 7 y, consistent with better attention. This exposure was not associated with K-CPT commission errors or with ANT omission or commission errors. Associations with residential surrounding tree cover also were close to the null, or were negative (for ANT HRT-SE) but not statistically significant. CONCLUSION: Exposure to residential surrounding greenness was associated with better scores on tests of attention at 4-5 y and 7 y of age in our longitudinal cohort. https://doi.org/10.1289/EHP694.

Prenatal and postnatal exposure to NO2 and child attentional function at 4-5years of age.

BACKGROUND: Prenatal and postnatal exposure to air pollution has been linked to cognitive impairment in children, but very few studies have assessed its association with attentional function. OBJECTIVES: To evaluate the association between prenatal and postnatal exposure to nitrogen dioxide (NO2) and attentional function in children at 4-5years of age. METHODS: We used data from four regions of the Spanish INMA-Environment and Childhood-Project, a population-based birth cohort. Using land-use regression models (LUR), we estimated prenatal and postnatal NO2 levels in all of these regions at the participants' residential addresses. We assessed attentional function using the Kiddie-Conners Continuous Performance Test (K-CPT). We combined the region-specific adjusted effect estimates using random-effects meta-analysis. RESULTS: We included 1298 children with complete data. Prenatal exposure to NO2 was associated with an impaired standard error of the hit reaction time (HRT(SE)) (increase of 1.12ms [95% CI; 0.22 a 2.02] per 10µg/m3 increase in prenatal NO2) and increased omission errors (6% [95% CI; 1.01 to 1.11] per 10µg/m3 increase in prenatal NO2). Postnatal exposure to NO2 resulted in a similar but borderline significant increase of omission errors (5% [95% CI; =0.99 to 1.11] per 10µg/m3 increase in postnatal NO2). These associations did not vary markedly between regions, and were mainly observed in girls. Commission errors and lower detectability were associated with prenatal and postnatal exposure to NO2 only in some regions. CONCLUSIONS: This study indicates that higher exposure to ambient NO2, mainly during pregnancy and to a lesser extent postnatally, is associated with impaired attentional function in children at 4-5years of age.

Urban green and grey space in relation to respiratory health in children.

We assessed the effect of three different indices of urban built environment on allergic and respiratory conditions.This study involved 2472 children participating in the ongoing INMA birth cohort located in two bio-geographic regions (Euro-Siberian and Mediterranean) in Spain. Residential surrounding built environment was characterised as 1) residential surrounding greenness based on satellite-derived normalised difference vegetation index (NDVI), 2) residential proximity to green spaces and 3) residential surrounding greyness based on urban land use patterns. Information on wheezing, bronchitis, asthma and allergic rhinitis up to age 4 years was obtained from parent-completed questionnaires. Logistic regression and generalised estimating equation modelling were performed.Among children from the Euro-Siberian region, higher residential surrounding greenness and higher proximity to green spaces were negatively associated with wheezing. In the Mediterranean region, higher residential proximity to green spaces was associated with a reduced risk for bronchitis. A higher amount of residential surrounding greyness was found to increase the risk for bronchitis in this region.Associations between indices of urban residential greenness and greyness with respiratory diseases differ by region. The pathways underlying these associations require further exploration.

Traffic-related air pollution and spectacles use in schoolchildren.

PURPOSE: To investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren. METHODS: We analyzed the impact of exposure to NO2 and PM2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO2 and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7-10 years old) in Barcelona (2012-2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates. RESULTS: An interquartile range increase in exposure to NO2 and PM2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO2 and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted. CONCLUSION: We observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors.