EXPOSURE TO AMBIENT HEAT AND RISK OF SPONTANEOUS ABORTION: A CASE-CROSSOVER STUDY.

BACKGROUND: Few epidemiologic studies have examined the association of ambient heat with spontaneous abortion, a common and devastating pregnancy outcome. METHODS: We conducted a case-crossover study nested within Pregnancy Study Online, a preconception cohort study (2013-2022). We included all participants reporting spontaneous abortion (n=1,524). We defined the case window as the 7 days preceding the event and used time-stratified referent selection to select control windows matched on calendar month and day of week. Within each 7-day case and control window, we measured mean, maximum, and minimum of daily maximum outdoor air temperatures. We fit splines to examine non-linear relationships across the entire year and conditional logistic regression to estimate odds ratios (OR) and 95% CI of spontaneous abortion with increases in temperature during the warm season (May-September) and decreases during the cool season (November-March). RESULTS: We found evidence of a U-shaped association between outdoor air temperature and spontaneous abortion risk based on year-round data. When restricting to warm season events (n=657), the OR for a 10-percentile increase in the mean of lag 0-6 daily maximum temperatures was 1.1 (95% CI: 0.96, 1.2) and, for the maximum, 1.1 (95% CI: 0.99, 1.2). The OR associated with any extreme heat days (>95th county-specific percentile) in the preceding week was 1.2 (95% CI: 0.95, 1.5). Among cool season events (n=615), there was no appreciable association between lower temperatures and spontaneous abortion risk. CONCLUSION: Our study provides evidence of an association between high outdoor temperatures and incidence of spontaneous abortion.

Exposure to residential greenness, perceived stress, and depressive symptoms in a North American preconception cohort.

BACKGROUND: Studies suggest that greater exposure to natural vegetation (i.e., greenness) is associated with better mental health. However, there is limited research on greenness and mental health in the preconception period, a critical window of exposure in the life course. We investigated the associations of residential greenness with perceived stress and depressive symptoms using cross-sectional data from a cohort of pregnancy planners. METHODS: From 2013 to 2019, we enrolled female-identified participants aged 21-45 years who were trying to conceive without the use of fertility treatment into a North American preconception cohort study (Pregnancy Study Online [PRESTO]). On the baseline questionnaire, participants completed the 10-item Perceived Stress Scale (PSS) and the Major Depression Inventory (MDI). Using geocoded addresses, we estimated residential greenness exposure via satellite imagery (Normalized Difference Vegetation Index [NDVI]) in a 100m buffer. We estimated mean differences and 95% confidence intervals for the association of greenness with perceived stress and depression scores using linear regression models, adjusting for individual and neighborhood sociodemographic characteristics. We also evaluated the extent to which associations were modified by urbanicity and neighborhood socioeconomic status (SES). RESULTS: Among 9718 participants, mean age was 29.9 years, 81.5% identified as non-Hispanic White, 25% had household incomes <$50,000, and mean neighborhood income was $61,932. In adjusted models, higher greenness was associated with lower stress and depression scores (mean difference per interquartile range in greenness: -0.20, 95% CI: -0.39, -0.01; and -0.19, 95% CI: -0.48, 0.10, respectively). The association was stronger among residents of lower SES neighborhoods in urban areas (PSS: -0.57, 95% CI: -1.00, -0.15; MDI: -0.72, 95% CI: -1.40, -0.04). CONCLUSIONS: Higher greenness exposure was associated with lower stress and depressive symptoms among pregnancy planners, particularly in lower-SES neighborhoods.

Estimating ambient air pollutant concentrations outside and inside homes in the Subpopulations and Intermediate outcomes in COPD air pollution (SPIROMICS air) cohort.

BACKGROUND: Valid, high-resolution estimates of population-level exposure to air pollutants are necessary for accurate estimation of the association between air pollution and the occurrence or exacerbation of adverse health outcomes such as Chronic Obstructive Pulmonary Disease (COPD). OBJECTIVES: We produced fine-scale individual-level estimates of ambient concentrations of multiple air pollutants (fine particulate matter [PM2.5], NOX, NO2, and O3) at residences of participants in the Subpopulations and Intermediate Outcomes in COPD Air Pollution (SPIROMICS Air) study, located in seven regions in the US. For PM2.5, we additionally integrated modeled estimates of particulate infiltration based on home characteristics and measured total indoor concentrations to provide comprehensive estimates of exposure levels. METHODS: To estimate ambient concentrations, we used a hierarchical high-resolution spatiotemporal model that integrates hundreds of geographic covariates and pollutant measurements from regulatory and study-specific monitors, including ones located at participant residences. We modeled infiltration efficiency based on data on house characteristics, home heating and cooling practices, indoor smoke and combustion sources, meteorological factors, and paired indoor-outdoor pollutant measurements, among other indicators. RESULTS: Cross-validated prediction accuracy (R2) for models of ambient concentrations was above 0.80 for most regions and pollutants. Particulate matter infiltration efficiency varied by region, from 0.51 in Winston-Salem to 0.72 in Los Angeles, and ambient-source particles constituted a substantial fraction of total indoor PM2.5. CONCLUSION: Leveraging well-validated fine-scale approaches for estimating outdoor, ambient-source indoor, and total indoor pollutant concentrations, we can provide comprehensive estimates of short and long-term exposure levels for cohorts undergoing follow-up in multiple different regions.

Ambient air pollution and rate of spontaneous abortion.

Spontaneous abortion (SAB), defined as a pregnancy loss before 20 weeks of gestation, affects up to 30% of conceptions, yet few modifiable risk factors have been identified. We estimated the effect of ambient air pollution exposure on SAB incidence in Pregnancy Study Online (PRESTO), a preconception cohort study of North American couples who were trying to conceive. Participants completed questionnaires at baseline, every 8 weeks during preconception follow-up, and in early and late pregnancy. We analyzed data on 4643 United States (U.S.) participants and 851 Canadian participants who enrolled during 2013-2019 and conceived during 12 months of follow-up. We used country-specific national spatiotemporal models to estimate concentrations of particulate matter <2.5 µm (PM2.5), nitrogen dioxide (NO2), and ozone (O3) during the preconception and prenatal periods at each participant's residential address. On follow-up and pregnancy questionnaires, participants reported information on pregnancy status, including SAB incidence and timing. We fit Cox proportional hazards regression models with gestational weeks as the time scale to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of time-varying prenatal concentrations of PM2.5, NO2, and O3 with rate of SAB, adjusting for individual- and neighborhood-level factors. Nineteen percent of pregnancies ended in SAB. Greater PM2.5 concentrations were associated with a higher incidence of SAB in Canada, but not in the U.S. (HRs for a 5 µg/m3 increase = 1.29, 95% CI: 0.99, 1.68 and 0.94, 95% CI: 0.83, 1.08, respectively). NO2 and O3 concentrations were not appreciably associated with SAB incidence. Results did not vary substantially by gestational weeks or season at risk. In summary, we found little evidence for an effect of residential ambient PM2.5, NO2, and O3 concentrations on SAB incidence in the U.S., but a moderate positive association of PM2.5 with SAB incidence in Canada.

A Prospective Cohort Study of Seasonal Variation in Spontaneous Abortion.

BACKGROUND: Up to 30% of pregnancies end in spontaneous abortion, yet few risk factors have been identified. Examining seasonal patterns in risk of spontaneous abortion can generate new hypotheses regarding environmental and lifestyle determinants. METHODS: We used data from Pregnancy Study Online-a preconception cohort study of pregnancy planners from the United States and Canada-to examine seasonal variation in spontaneous abortion risk. We enrolled 12,197 women during 2013 to 2020, 6104 of whom reported a conception within 12 months of enrollment. On follow-up questionnaires, participants reported date of spontaneous abortion and weeks gestation at time of loss. We used periodic regression to estimate two aspects of seasonal occurrence: peak/low ratio-a measure of intensity of seasonal variation-and peak timing. We examined season at risk (from the date of each gestational week) in relation to spontaneous abortion; in a secondary analysis, we examined season of conception in relation to spontaneous abortion. We controlled for seasonal patterns in attempt initiation via month the pregnancy attempt began. RESULTS: Almost 20% of women experienced spontaneous abortion. Risk was highest in late August, with a peak/low ratio of 1.3 (95% confidence interval [CI] = 1.1, 1.6). This seasonal pattern was evident almost exclusively for spontaneous abortion at <8 weeks since the last menstrual period date (peak/low ratio = 1.4; 95% CI = 1.2, 1.8), and associations were stronger among women living in the Southern and Midwestern United States. CONCLUSIONS: Environmental or lifestyle factors more prevalent in late summer may be associated with increased risk of early spontaneous abortion.

Patient Transfers and Their Impact on Gaps in Clinical Care: Differences by Gender in a Large Cohort of Adults Living with HIV on Antiretroviral Therapy in South Africa.

For people living with HIV (PLWH), patient transfers may affect engagement in care. We followed a cohort of PLWH in Cape Town, South Africa who tested positive for HIV in 2012-2013 from ART initiation in 2012-2016 through December 2016. Patient transfers were defined as moving from one healthcare facility to another on a different day, considering all healthcare visits and recorded HIV-visits only. We estimated incidence rates (IR) for transfers by time since ART initiation, overall and by gender, and associations between transfers and gaps of > 180 days in clinical care. Overall, 4,176 PLWH were followed for a median of 32 months, and 8% (HIV visits)-17% (all healthcare visits) of visits were patient transfers. Including all healthcare visits, transfers were highest through 3 months on ART (IR 20.2 transfers per 100 visits, 95% CI 19.2-21.2), but increased through 36 months on ART when only HIV visits were included (IR 9.7, 95% CI 8.8-10.8). Overall, women were more likely to transfer than men, and transfers were associated with gaps in care (IR ratio [IRR] 3.06 95% CI 2.83-3.32; HIV visits only). In this cohort, patient transfers were frequent, more common among women, and associated with gaps in care.

Preterm birth and PM2.5 in Puerto Rico: evidence from the PROTECT birth cohort.

BACKGROUND: Preterm birth (PTB, birth before 37 weeks of gestation) has been associated with adverse health outcomes across the lifespan. Evidence on the association between PTB and prenatal exposure to air pollutants is inconsistent, and is especially lacking for ethnic/racial minority populations. METHODS: We obtained data on maternal characteristics and behaviors and PTB and other birth outcomes for women participating in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) cohort, who lived in municipalities located along the North Coast of Puerto Rico. We assessed pre-natal PM2.5 exposures for each infant based on the nearest US Environmental Protection Agency monitor. We estimated prenatal phthalate exposures as the geometric mean of urinary measurements obtained during pregnancy. We then examined the association between PM2.5 and PTB using modified Poisson regression and assessed modification of the association by phthalate exposure levels and sociodemographic factors such as maternal age and infant gender. RESULTS: Among 1092 singleton births, 9.1% of infants were born preterm and 92.9% of mothers had at least a high school education. Mothers had a mean (standard deviation) age of 26.9 (5.5) years and a median (range) of 2.0 (1.0-8.0) pregnancies. Nearly all women were Hispanic white, black, or mixed race. Median (range) prenatal PM2.5 concentrations were 6.0 (3.1-19.8) µ g/m3. Median (interquartile range) prenatal phthalate levels were 14.9 (8.9-26.0) and 14.5 (8.4-26.0), respectively, for di-n-butyl phthalate (DBP) and di-isobutyl phthalate (DiBP). An interquartile range increase in PM2.5 was associated with a 1.2% (95% CI 0.4, 2.1%) higher risk of PTB. There was little difference in PTB risk in strata of infant sex, mother's age, family income, history of adverse birth outcome, parity, and pre-pregnancy body mass index. Pregnancy urinary phthalate metabolite levels did not modify the PM2.5-PTB association. CONCLUSION: Among ethnic minority women in Puerto Rico, prenatal PM2.5 exposure is associated with a small but significant increase in risk of PTB.

Modeling residential indoor concentrations of PM2.5 , NO2 , NOx , and secondhand smoke in the Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) Air study.

Increased outdoor concentrations of fine particulate matter (PM2.5 ) and oxides of nitrogen (NO2 , NOx ) are associated with respiratory and cardiovascular morbidity in adults and children. However, people spend most of their time indoors and this is particularly true for individuals with chronic obstructive pulmonary disease (COPD). Both outdoor and indoor air pollution may accelerate lung function loss in individuals with COPD, but it is not feasible to measure indoor pollutant concentrations in all participants in large cohort studies. We aimed to understand indoor exposures in a cohort of adults (SPIROMICS Air, the SubPopulations and Intermediate Outcome Measures in COPD Study of Air pollution). We developed models for the entire cohort based on monitoring in a subset of homes, to predict mean 2-week-measured concentrations of PM2.5 , NO2 , NOx , and nicotine, using home and behavioral questionnaire responses available in the full cohort. Models incorporating socioeconomic, meteorological, behavioral, and residential information together explained about 60% of the variation in indoor concentration of each pollutant. Cross-validated R2 for best indoor prediction models ranged from 0.43 (NOx ) to 0.51 (NO2 ). Models based on questionnaire responses and estimated outdoor concentrations successfully explained most variation in indoor PM2.5 , NO2 , NOx , and nicotine concentrations.

Estimating retention in HIV care accounting for clinic transfers using electronic medical records: evidence from a large antiretroviral treatment programme in the Western Cape, South Africa.

BACKGROUND: Estimates of retention in antiretroviral treatment (ART) programmes may be biased if patients who transfer to healthcare clinics are misclassified as lost to follow-up (LTFU) at their original clinic. In a large cohort, we estimated retention in care accounting for patient transfers using medical records. METHODS: Using linked electronic medical records, we followed adults living with HIV (PLWH) in Cape Town, South Africa from ART initiation (2012-2016) through database closure at 36 months or 30 June 2016, whichever came first. Retention was defined as alive and with a healthcare visit in the 180 days between database closure and administrative censoring on 31 December 2016. Participants who died or did not have a healthcare visit in > 180 days were censored at their last healthcare visit. We estimated the cumulative incidence of retention using Kaplan-Meier methods considering (i) only records from a participant's ART initiation clinic (not accounting for transfers) and (ii) all records (accounting for transfers), over time and by gender. We estimated risk differences and bootstrapped 95% confidence intervals to quantify misclassification in retention estimates due to patient transfers. RESULTS: We included 3406 PLWH initiating ART. Retention through 36 months on ART rose from 45.4% (95% CI 43.6%, 47.2%) to 54.3% (95% CI 52.4%, 56.1%) after accounting for patient transfers. Overall, 8.9% (95% CI 8.1%, 9.7%) of participants were misclassified as LTFU due to patient transfers. CONCLUSIONS: Patient transfers can appreciably bias estimates of retention in HIV care. Electronic medical records can help quantify patient transfers and improve retention estimates.

CONTEXTE: Les estimations de la rétention dans les programmes de traitement antirétroviral (ART) peuvent être biaisées si les patients qui sont transférés dans des cliniques de soins de santé sont classés à tort comme perdus au suivi (PS) dans leur clinique d'origine. Dans une large cohorte, nous avons estimé la rétention dans les soins en tenant compte des transferts de patients à l'aide des dossiers médicaux. MÉTHODES: A l'aide de dossiers médicaux électroniques reliés entre eux, nous avons suivi des adultes vivant avec le VIH (PVVIH) à Cape Town, en Afrique du Sud, depuis le début de l'ART (2012-2016) jusqu'à la clotûre de la base de données à 36 mois ou au 30 juin 2016, selon la première éventualité. La rétention a été définie comme étant en vie et avec une visite médicale dans les 180 jours entre la clôture de la base de données et recensement administrative le 31 décembre 2016. Les participants qui sont décédés ou qui n'ont pas eu de visite médicale dans un délai de plus de 180 jours ont été recensés lors de leur dernière visite médicale. Nous avons estimé l'incidence cumulative de la rétention en utilisant les méthodes de Kaplan-Meier en considérant: (i) uniquement les dossiers de la clinique d'initiation de l'ART d'un participant (sans tenir compte des transferts) et (ii) tous les dossiers (en tenant compte des transferts), au cours du temps et par sexe. Nous avons estimé les différences de risque et avons considéré des intervalles de confiance à 95% pour quantifier les erreurs de classification dans les estimations de rétention dues aux transferts de patients. RÉSULTAT: Nous avons inclus 3.406 PVVIH qui ont commencé un ART. La rétention sous ART est passée de 45,4% (IC 95%: 43,6-47,2) à 54,3% (IC 95%: 52,4-56,1) après avoir tenu compte des transferts de patients. Dans l'ensemble, 8,9% (IC 95%: 8,1-9,7) des participants ont été classés à tort dans la catégorie PS en raison des transferts de patients. CONCLUSIONS: Les transferts de patients peuvent biaiser sensiblement les estimations de la rétention dans les soins liés au VIH. Les dossiers médicaux électroniques peuvent aider à quantifier les transferts de patients et à améliorer les estimations de rétention.

Quantifying the HIV treatment cascade in a South African health sub-district by gender: retrospective cohort study.

OBJECTIVES: To quantify the HIV care cascade in a Cape Town sub-district to understand rates of linkage to and engagement in HIV care. METHODS: We used routinely collected data to reconstruct the treatment cascade for 8382 infected individuals who tested HIV + in 2012/2013. We obtained data on patient gender, year of initial HIV-positive test, age at testing and initial CD4 cell count and defined five stages of the HIV care cascade. We quantified attrition across cascade stages. RESULTS: Two-thirds of the sample (5646) were women. Men were older at time of first testing (36.5 vs. 31.3 years) and had more advanced HIV disease at diagnosis (298 vs. 404 CD4 cells/µL for women). The median duration of follow-up was 818 days. Among women, 90.5% attended an initial HIV care visit, 54.6% became eligible for antiretroviral therapy under local guidelines during follow-up, 49.3% initiated ART and 45.6% achieved a therapeutic response. Among men, 88.0% attended an initial HIV care visit, 67.4% became ART eligible during follow-up, 48.0% initiated ART and 42.4% achieved a therapeutic response. Approximately 3% of women and 5% of men died during follow-up. CONCLUSIONS: We were able to reconstruct the HIV treatment cascade using routinely collected data. In this setting, rates of engagement in care differ by gender in key stages of the cascade, with men faring worse than women at each cascade point. This highlights the need for interventions aimed at encouraging earlier testing, linkage, ART initiation and retention among men.

OBJECTIFS: Quantifier la cascade des soins du VIH dans un sous-district de Cape Town pour comprendre les taux de liaisons et d'engagement avec les soins du VIH. MÉTHODES: Nous avons utilisé des données collectées en routine pour reconstruire la cascade de traitement pour 8.382 personnes infectées, testées positives pour le VIH en 2012/13. Nous avons obtenu des données sur le sexe du patient, l'année du premier test positif pour le VIH, l'âge au moment de ce test et le nombre initial de cellules CD4, et avons défini cinq étapes de la cascade des soins du VIH. Nous avons quantifié l'attrition au long des étapes de la cascade. RÉSULTATS: Deux tiers de l'échantillon (5.646) étaient des femmes. Les hommes étaient plus âgés au moment du premier test (36,5 contre 31,3 ans) et avaient la maladie du VIH plus avancée au moment du diagnostic (298 contre 404 cellules CD4/µL pour les femmes). La durée médiane de suivi était de 818 jours. Parmi les femmes, 90,5% ont pris part à une première visite pour des soins du VIH, 54,6% sont devenues éligibles au traitement antirétroviral selon les directives locales au cours du suivi, 49,3% ont commencé une ART et 45,6% ont atteint une réponse thérapeutique. Chez les hommes, 88,0% ont pris part à une première visite pour les soins du VIH; 67,4% sont devenus éligibles à l'ART au cours du suivi, 48,0% ont commencé l'ART et 42,4% ont atteint une réponse thérapeutique. Environ 3% des femmes et 5% des hommes sont décédés au cours du suivi. CONCLUSIONS: Nous avons pu reconstruire la cascade de traitement du VIH en utilisant des données collectées en routine. Dans ce contexte, les taux d'engagement dans les soins diffèrent selon le sexe dans les étapes clés de la cascade, les hommes s'en tirant moins bien que les femmes à chaque point de la cascade. Cela met en évidence la nécessité d'interventions visant à encourager le dépistage précoce, la liaison, l'initiation de l'ART et la rétention chez les hommes.

Association Between Long-term Exposure to Ambient Air Pollution and Change in Quantitatively Assessed Emphysema and Lung Function.

Importance: While air pollutants at historical levels have been associated with cardiovascular and respiratory diseases, it is not known whether exposure to contemporary air pollutant concentrations is associated with progression of emphysema. Objective: To assess the longitudinal association of ambient ozone (O3), fine particulate matter (PM2.5), oxides of nitrogen (NOx), and black carbon exposure with change in percent emphysema assessed via computed tomographic (CT) imaging and lung function. Design, Setting, and Participants: This cohort study included participants from the Multi-Ethnic Study of Atherosclerosis (MESA) Air and Lung Studies conducted in 6 metropolitan regions of the United States, which included 6814 adults aged 45 to 84 years recruited between July 2000 and August 2002, and an additional 257 participants recruited from February 2005 to May 2007, with follow-up through November 2018. Exposures: Residence-specific air pollutant concentrations (O3, PM2.5, NOx, and black carbon) were estimated by validated spatiotemporal models incorporating cohort-specific monitoring, determined from 1999 through the end of follow-up. Main Outcomes and Measures: Percent emphysema, defined as the percent of lung pixels less than -950 Hounsfield units, was assessed up to 5 times per participant via cardiac CT scan (2000-2007) and equivalent regions on lung CT scans (2010-2018). Spirometry was performed up to 3 times per participant (2004-2018). Results: Among 7071 study participants (mean [range] age at recruitment, 60 [45-84] years; 3330 [47.1%] were men), 5780 were assigned outdoor residential air pollution concentrations in the year of their baseline examination and during the follow-up period and had at least 1 follow-up CT scan, and 2772 had at least 1 follow-up spirometric assessment, over a median of 10 years. Median percent emphysema was 3% at baseline and increased a mean of 0.58 percentage points per 10 years. Mean ambient concentrations of PM2.5 and NOx, but not O3, decreased substantially during follow-up. Ambient concentrations of O3, PM2.5, NOx, and black carbon at study baseline were significantly associated with greater increases in percent emphysema per 10 years (O3: 0.13 per 3 parts per billion [95% CI, 0.03-0.24]; PM2.5: 0.11 per 2 µg/m3 [95% CI, 0.03-0.19]; NOx: 0.06 per 10 parts per billion [95% CI, 0.01-0.12]; black carbon: 0.10 per 0.2 µg/m3 [95% CI, 0.01-0.18]). Ambient O3 and NOx concentrations, but not PM2.5 concentrations, during follow-up were also significantly associated with greater increases in percent emphysema. Ambient O3 concentrations, but not other pollutants, at baseline and during follow-up were significantly associated with a greater decline in forced expiratory volume in 1 second per 10 years (baseline: 13.41 mL per 3 parts per billion [95% CI, 0.7-26.1]; follow-up: 18.15 mL per 3 parts per billion [95% CI, 1.59-34.71]). Conclusions and Relevance: In this cohort study conducted between 2000 and 2018 in 6 US metropolitan regions, long-term exposure to ambient air pollutants was significantly associated with increasing emphysema assessed quantitatively using CT imaging and lung function.

Projected Changes in Temperature-related Morbidity and Mortality in Southern New England.

BACKGROUND: Climate change is expected to result in more heat-related, but potentially fewer cold-related, emergency department visits and deaths. The net effect of projected changes in temperature on morbidity and mortality remains incompletely understood. We estimated the change in temperature-related morbidity and mortality at two sites in southern New England, United States, through the end of the 21st century. METHODS: We used distributed lag Poisson regression models to estimate the present-day associations between daily mean temperature and all-cause emergency department visits and deaths in Rhode Island and in Boston, Massachusetts. We estimated the change in temperature-related visits and deaths in 2045-2054 and 2085-2094 (relative to 2001-2010) under two greenhouse gas emissions scenarios (RCP4.5 and RCP8.5) using downscaled projections from an ensemble of over 40 climate models, assuming all other factors remain constant. RESULTS: We observed U-shaped relationships between temperature and morbidity and mortality in Rhode Island, with minima at 10.9°C and 22.5°C, respectively. We estimated that, if this population were exposed to the future temperatures projected under RCP8.5 for 2085-2094, there would be 5,976 (95% eCI = 1,630, 11,379) more emergency department visits but 218 (95% eCI = -551, 43) fewer deaths annually. Results were similar in Boston and similar but less pronounced in the 2050s and under RCP4.5. CONCLUSIONS: We estimated that in the absence of further adaptation, if the current southern New England population were exposed to the higher temperatures projected for future decades, temperature-related emergency department visits would increase but temperature-related deaths would not.

Effectiveness of peer-led interventions to increase HIV testing among men who have sex with men: a systematic review and meta-analysis.

HIV testing constitutes a key step along the continuum of HIV care. Men who have sex with men (MSM) have low HIV testing rates and delayed diagnosis, especially in low-resource settings. Peer-led interventions offer a strategy to increase testing rates in this population. This systematic review and meta-analysis summarizes evidence on the effectiveness of peer-led interventions to increase the uptake of HIV testing among MSM. Using a systematic review protocol that was developed a priori, we searched PubMed, PsycINFO and CINAHL for articles reporting original results of randomized or non-randomized controlled trials (RCTs), quasi-experimental interventions, and pre- and post-intervention studies. Studies were eligible if they targeted MSM and utilized peers to increase HIV testing. We included studies published in or after 1996 to focus on HIV testing during the era of combination antiretroviral therapy. Seven studies encompassing a total of 6205 participants met eligibility criteria, including two quasi-experimental studies, four non-randomized pre- and-post intervention studies, and one cluster randomized trial. Four studies were from high-income countries, two were from Asia and only one from sub-Saharan Africa. We assigned four studies a "moderate" methodological rigor rating and three a "strong" rating. Meta-analysis of the seven studies found HIV testing rates were statistically significantly higher in the peer-led intervention groups versus control groups (pooled OR 2.00, 95% CI 1.74-2.31). Among randomized trials, HIV testing rates were significantly higher in the peer-led intervention versus control groups (pooled OR: 2.48, 95% CI 1.99-3.08). Among the non-randomized pre- and post-intervention studies, the overall pooled OR for intervention versus control groups was 1.71 (95% CI 1.42-2.06), with substantial heterogeneity among studies (I2 = 70%, p < 0.02). Overall, peer-led interventions increased HIV testing among MSM but more data from high-quality studies are needed to evaluate effects of peer-led interventions on HIV testing among MSM in low- and middle-income countries.

High burden of STIs among HIV-infected adults prior to initiation of ART in South Africa: a retrospective cohort study.

OBJECTIVES: To assess the burden of sexually transmitted infections (STIs) among HIV-positive South Africans in the period prior to antiretroviral therapy (ART) initiation compared with the period once on ART. METHODS: We linked the clinic records of 1465 patients currently on ART to the electronic database which records all visits to city clinics. We used a mixed effects Poisson model to assess the relative rates of occurrence of treatment seeking for an STI in the periods prior to initiation of ART and while on ART. RESULTS: We accumulated 4214 person-years of follow-up, divided nearly equally between the pre-ART and on-ART periods. The rate of treatment seeking for new STIs was 5.50 (95% CI 5.43 to 5.78) per 100 person-years, and individuals had on average a sevenfold higher rate of seeking treatment for STIs in the period prior to initiating ART (9.57 per 100 person-years) compared with the period once on ART (5.5 per 100 person-years) (adjusted rate ratio (RR) 7.01, 95% CI 4.64 to 10.59). Being male (RR 1.73, 95% CI 1.18 to 2.55) or younger (age <25) (RR 2.67, 95% CI 1.53 to 4.65) was associated with higher incidence of clinic visits for STI treatment, while advanced stage of HIV disease (WHO stage 4) (RR 0.33, 95% CI 0.15 to 0.69) was associated with lower incidence. CONCLUSIONS: The period prior to the initiation of ART is a critical period where increased attention should be focused on the detection and treatment of STIs. A successful effort to treat STIs in this period will likely reduce further HIV transmission and fits within a test-and-treat approach.

Methylomic, proteomic, and metabolomic correlates of traffic-related air pollution: A systematic review, pathway analysis, and network analysis relating traffic-related air pollution to subclinical and clinical cardiorespiratory outcomes.

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease, and highlight contemporary challenges and opportunities associated with such efforts.

Methylomic, Proteomic, and Metabolomic Correlates of Traffic-Related Air Pollution in the Context of Cardiorespiratory Health: A Systematic Review, Pathway Analysis, and Network Analysis.

A growing body of literature has attempted to characterize how traffic-related air pollution (TRAP) affects molecular and subclinical biological processes in ways that could lead to cardiorespiratory disease. To provide a streamlined synthesis of what is known about the multiple mechanisms through which TRAP could lead to cardiorespiratory pathology, we conducted a systematic review of the epidemiological literature relating TRAP exposure to methylomic, proteomic, and metabolomic biomarkers in adult populations. Using the 139 papers that met our inclusion criteria, we identified the omic biomarkers significantly associated with short- or long-term TRAP and used these biomarkers to conduct pathway and network analyses. We considered the evidence for TRAP-related associations with biological pathways involving lipid metabolism, cellular energy production, amino acid metabolism, inflammation and immunity, coagulation, endothelial function, and oxidative stress. Our analysis suggests that an integrated multi-omics approach may provide critical new insights into the ways TRAP could lead to adverse clinical outcomes. We advocate for efforts to build a more unified approach for characterizing the dynamic and complex biological processes linking TRAP exposure and subclinical and clinical disease and highlight contemporary challenges and opportunities associated with such efforts.

Associations between Residential Greenspace and Fecundability in a North American Preconception Cohort Study.

BACKGROUND: Residential green space can have positive physiological effects on human health through various mechanisms, including reducing stress and/or depression or facilitating physical activity. Although green space has been consistently associated with improved birth outcomes in several studies, there has been limited study of its effect on other reproductive outcomes, including fertility. OBJECTIVE: We examined associations between residential green space and fecundability, the per-cycle probability of conception. METHODS: We analyzed data from 8,563 female participants enrolled between 2013 and 2019 in Pregnancy Study Online (PRESTO), a prospective preconception cohort study of North American couples attempting conception. Participants completed a baseline questionnaire on sociodemographic, behavioral, and reproductive factors, and bimonthly follow-up questionnaires for up to 12 months to ascertain pregnancies. Using geocoded addresses, we calculated residential green space exposure using the Normalized Difference Vegetation Index (NDVI) within 50-, 100-, 250-, and 500-m buffers across multiple temporal scales: annual maximum, seasonal maximum, and seasonal mean. We used proportional probabilities regression models to estimate fecundability ratios (FRs), adjusting for sociodemographic, behavioral, and neighborhood characteristics. We also evaluated the extent to which associations were mediated by reductions in perceived stress or depressive symptoms and increased physical activity. RESULTS: When comparing the highest (≥0.8) with the lowest (<0.2) NDVI exposures within 50m, we observed positive associations in the annual maximum NDVI [FR: 1.33; 95% confidence interval (CI): 1.06, 1.67] and seasonal maximum NDVI (FR: 1.19; 95% CI: 1.00, 1.41) models, but little association in the seasonal mean NDVI models (FR: 0.98; 95% CI: 0.73, 1.30). Restricted cubic splines showed evidence of nonlinearity in this association. Results were similar across buffer distances. Perceived stress, depressive symptoms, and physical activity explained ≤5:0% of mediation across all NDVI metrics. DISCUSSION: In this cohort, greater residential green space was associated with a modest increase in fecundability. https://doi.org/10.1289/EHP10648.

Air pollution and fecundability in a North American preconception cohort study.

BACKGROUND: Animal and epidemiologic studies indicate that air pollution may adversely affect fertility. However, the level of evidence is limited and specific pollutants driving the association are inconsistent across studies. METHODS: We used data from a web-based preconception cohort study of pregnancy planners enrolled during 2013-2019 (Pregnancy Study Online; PRESTO). Eligible participants self-identified as female, were aged 21-45 years, resided in the United States (U.S.) or Canada, and were trying to conceive without fertility treatments. Participants completed a baseline questionnaire and bi-monthly follow-up questionnaires until conception or 12 months. We analyzed data from 8,747 participants (U.S.: 7,304; Canada: 1,443) who had been trying to conceive for < 12 cycles at enrollment. We estimated residential ambient concentrations of particulate matter < 2.5 µm (PM2.5), nitrogen dioxide (NO2), and ozone (O3) using validated spatiotemporal models specific to each country. We fit country-specific proportional probabilities regression models to estimate the association between annual average, menstrual cycle-specific, and preconception average pollutant concentrations with fecundability, the per-cycle probability of conception. We calculated fecundability ratios (FRs) and 95% confidence intervals (CIs) and adjusted for individual- and neighborhood-level confounders. RESULTS: In the U.S., the FRs for a 5-µg/m3 increase in annual average, cycle-specific, and preconception average PM2.5 concentrations were 0.94 (95% CI: 0.83, 1.08), 1.00 (95% CI: 0.93, 1.07), and 1.00 (95% CI: 0.93, 1.09), respectively. In Canada, the corresponding FRs were 0.92 (95% CI: 0.74, 1.16), 0.97 (95% CI: 0.87, 1.09), and 0.94 (95% CI: 0.80, 1.09), respectively. Likewise, NO2 and O3 concentrations were not strongly associated with fecundability in either country. CONCLUSIONS: Neither annual average, menstrual cycle-specific, nor preconception average exposure to ambient PM2.5, NO2, and O3 were appreciably associated with reduced fecundability in this cohort of pregnancy planners.

Within-City Variation in Ambient Carbon Monoxide Concentrations: Leveraging Low-Cost Monitors in a Spatiotemporal Modeling Framework.

BACKGROUND: Based on human and animal experimental studies, exposure to ambient carbon monoxide (CO) may be associated with cardiovascular disease outcomes, but epidemiological evidence of this link is limited. The number and distribution of ground-level regulatory agency monitors are insufficient to characterize fine-scale variations in CO concentrations. OBJECTIVES: To develop a daily, high-resolution ambient CO exposure prediction model at the city scale. METHODS: We developed a CO prediction model in Baltimore, Maryland, based on a spatiotemporal statistical algorithm with regulatory agency monitoring data and measurements from calibrated low-cost gas monitors. We also evaluated the contribution of three novel parameters to model performance: high-resolution meteorological data, satellite remote sensing data, and copollutant (PM2.5, NO2, and NOx) concentrations. RESULTS: The CO model had spatial cross-validation (CV) R2 and root-mean-square error (RMSE) of 0.70 and 0.02 parts per million (ppm), respectively; the model had temporal CV R2 and RMSE of 0.61 and 0.04 ppm, respectively. The predictions revealed spatially resolved CO hot spots associated with population, traffic, and other nonroad emission sources (e.g., railroads and airport), as well as sharp concentration decreases within short distances from primary roads. DISCUSSION: The three novel parameters did not substantially improve model performance, suggesting that, on its own, our spatiotemporal modeling framework based on geographic features was reliable and robust. As low-cost air monitors become increasingly available, this approach to CO concentration modeling can be generalized to resource-restricted environments to facilitate comprehensive epidemiological research. https://doi.org/10.1289/EHP10889.