Ambient Air Pollutant Exposures and COVID-19 Severity and Mortality in a Cohort of Patients with COVID-19 in Southern California.

Rationale: Ecological studies have shown air pollution associations with coronavirus disease (COVID-19) outcomes. However, few cohort studies have been conducted. Objectives: To conduct a cohort study investigating the association between air pollution and COVID-19 severity using individual-level data from the electronic medical record. Methods: This cohort included all individuals who received diagnoses of COVID-19 from Kaiser Permanente Southern California between March 1 and August 31, 2020. One-year and 1-month averaged ambient air pollutant (particulate matter ⩽2.5 µm in aerodynamic diameter [PM2.5], NO2, and O3) exposures before COVID-19 diagnosis were estimated on the basis of residential address history. Outcomes included COVID-19-related hospitalizations, intensive respiratory support (IRS), and ICU admissions within 30 days and mortality within 60 days after COVID-19 diagnosis. Covariates included socioeconomic characteristics and comorbidities. Measurements and Main Results: Among 74,915 individuals (mean age, 42.5 years; 54% women; 66% Hispanic), rates of hospitalization, IRS, ICU admission, and mortality were 6.3%, 2.4%, 1.5%, and 1.5%, respectively. Using multipollutant models adjusted for covariates, 1-year PM2.5 and 1-month NO2 average exposures were associated with COVID-19 severity. The odds ratios associated with a 1-SD increase in 1-year PM2.5 (SD, 1.5 µg/m3) were 1.24 (95% confidence interval [CI], 1.16-1.32) for COVID-19-related hospitalization, 1.33 (95% CI, 1.20-1.47) for IRS, and 1.32 (95% CI, 1.16-1.51) for ICU admission; the corresponding odds ratios associated with 1-month NO2 (SD, 3.3 ppb) were 1.12 (95% CI, 1.06-1.17) for hospitalization, 1.18 (95% CI, 1.10-1.27) for IRS, and 1.21 (95% CI, 1.11-1.33) for ICU admission. The hazard ratios for mortality were 1.14 (95% CI, 1.02-1.27) for 1-year PM2.5 and 1.07 (95% CI, 0.98-1.16) for 1-month NO2. No significant interactions with age, sex or ethnicity were observed. Conclusions: Ambient PM2.5 and NO2 exposures may affect COVID-19 severity and mortality.

The longitudinal associations of physical activity, time spent outdoors in nature and symptoms of depression and anxiety during COVID-19 quarantine and social distancing in the United States.

Stressors associated with COVID-19 pandemic stay-at-home orders are associated with increased depression and anxiety and decreased physical activity. Given that physical activity and time spent outdoors in nature are associated with improved mental health, we examined the longitudinal association of these variables during the pandemic. Over 20,000 adults who participated in the U.S. Kaiser Permanente Research Bank, did not report COVID-19 symptoms, and responded to an online baseline and 3 follow-up surveys over approximately 3 months formed the cohort. Physical activity was assessed from a modified survey, time spent outdoors was assessed from one question, and anxiety and depression scores were assessed from validated instruments. Almost 60% were women, 82.8% were non-Hispanic white, and more than 93% of respondents were over the age of 50. Less in-person contact with friends and visiting crowded places was highly prevalent (>80%) initially and decreased somewhat (>70%). Participants in the lowest physical activity category (no physical activity) had the highest depression and anxiety scores compared to each successive physical activity category (p < 0.001). Spending less time outdoors was associated with higher depression and anxiety scores. This effect was greater for participants in the younger age categories compared with older age categories. The effect of less time spent outdoors on anxiety (p = 0.012) and depression (p < 0.001) scores was smaller for males than females. Results suggest that physical activity and time outdoors is associated with better mental health. People should be encouraged to continue physical activity participation during public health emergencies.

Ambient air pollution and COVID-19 incidence during four 2020-2021 case surges.

BACKGROUND: Air pollution exposure may make people more vulnerable to COVID-19 infection. However, previous studies in this area mostly focused on infection before May 2020 and long-term exposure. OBJECTIVE: To assess both long-term and short-term exposure to air pollution and COVID-19 incidence across four case surges from 03/1/2020 to 02/28/2021. METHODS: The cohort included 4.6 million members from a large integrated health care system in southern California with comprehensive electronic medical records (EMR). COVID-19 cases were identified from EMR. Incidence of COVID-19 was computed at the census tract-level among members. Prior 1-month and 1-year averaged air pollutant levels (PM2.5, NO2, and O3) at the census tract-level were estimated based on hourly and daily air quality data. Data analyses were conducted by each wave: 3/1/2020-5/31/2020, 6/1/202-9/30/2020, 10/1/2020-12/31/2020, and 1/1/2021-2/28/2021 and pooled across waves using meta-analysis. Generalized linear mixed effects models with Poisson distribution and spatial autocorrelation were used with adjustment for meteorological factors and census tract-level social and health characteristics. Results were expressed as relative risk (RR) per 1 standard deviation. RESULTS: The cohort included 446,440 COVID-19 cases covering 4609 census tracts. The pooled RRs (95% CI) of COVID-19 incidence associated with 1-year exposures to PM2.5, NO2, and O3 were 1.11 (1.04, 1.18) per 2.3 µg/m3,1.09 (1.02, 1.17) per 3.2 ppb, and 1.06 (1.00, 1.12) per 5.5 ppb respectively. The corresponding RRs (95% CI) associated with prior 1-month exposures were 1.11 (1.03, 1.20) per 5.2 µg/m3 for PM2.5, 1.09 (1.01, 1.17) per 6.0 ppb for NO2 and 0.96 (0.85, 1.08) per 12.0 ppb for O3. CONCLUSION: Long-term PM2.5 and NO2 exposures were associated with increased risk of COVID-19 incidence across all case surges before February 2021. Short-term PM2.5 and NO2 exposures were also associated. Our findings suggest that air pollution may play a role in increasing the risk of COVID-19 infection.

Intrapartum Antibiotic Exposure and Body Mass Index in Children.

BACKGROUND: Intrapartum antibiotic prophylaxis (IAP) reduces a newborn's risk of group B streptococcal infection (GBS) but may lead to an increased childhood body mass index (BMI). METHODS: This was a retrospective cohort study of infants (n = 223 431) born 2007-2015 in an integrated healthcare system. For vaginal delivery, we compared children exposed to GBS-IAP and to any other type or duration of intrapartum antibiotics to no antibiotic exposure. For cesarean delivery, we compared children exposed to GBS-IAP to those exposed to all other intrapartum antibiotics, including surgical prophylaxis. BMI over 5 years was compared using nonlinear multivariate models with B-spline functions, stratified by delivery mode and adjusted for demographics, maternal factors, breastfeeding, and childhood antibiotic exposure. RESULTS: In vaginal deliveries, GBS-IAP was associated with higher BMI from 0.5 to 5.0 years of age compared to no antibiotics (P < .0001 for all time points, ΔBMI at age 5 years 0.12 kg/m2, 95% confidence interval [CI]: .07-.16 kg/m2). Other antibiotics were associated with higher BMI from 0.3 to 5.0 years of age. In cesarean deliveries, GBS-IAP was associated with increased BMI from 0.7 years to 5.0 years of age (P < .05 for 0.7-0.8 years, P < .0001 for all other time points) compared to other antibiotics (ΔBMI at age 5 years 0.24 kg/m2, 95% CI: .14-.34 kg/m2). Breastfeeding did not modify these associations. CONCLUSIONS: GBS-IAP was associated with a small but sustained increase in BMI starting at very early age. This association highlights the need to better understand the effects of perinatal antibiotic exposure on childhood health.

Statins as a free pass: Body mass index and other cardiovascular risk factors among lipid-lowering medication users and nonusers in the California Men's Health Study.

To lower risk from cardiovascular disease (CVD), national guidelines recommend lifestyle changes followed by use of lipid-lowering medications when appropriate. Previous studies have questioned whether individuals taking these medications are less likely to modify their dietary intake and physical activity, resulting in increased body mass index (BMI). We assessed BMI and CVD clinical risk factors over time between lipid-lowering medication users and nonusers in a diverse cohort of middle-aged and older men. The cohort consisted of 63,357 men who enrolled in the California Men's Health Study between 2002 and 2003 and were not taking lipid-lowering medications at baseline. Lipid-lowering medication use was determined over twelve years of follow-up. BMI and other CVD risk factors were assessed with longitudinal linear mixed effect models adjusting for possible confounders. Overall, lipid-lowering medication users had higher BMI than nonusers (p < .0001); however, there was a decrease over time for both groups (p < .0001). Total cholesterol, LDL-C, and triglycerides decreased for users and nonusers (p < .0001). While HDL-C was higher for nonusers (p < .05), over time this measure increased in both groups (p < .0001). We found no evidence of increases in BMI after initiation of lipid-lowering medication in this cohort. Instead, BMI decreased and several cholesterol-related CVD risk factors improved for lipid-lowering medication users and nonusers. This suggests that men placed on lipid-lowering medications do not view them as a panacea for their increased risk of cardiovascular disease. Instead, they appear to perceive them as one component of a multi-pronged strategy including lifestyle and nutrition as suggested by current guidelines.

Serum Phosphorus Levels, Race, and Socioeconomic Status in Incident Hemodialysis Patients.

OBJECTIVE: We sought to examine the relationship between race, socioeconomic status, and serum phosphorus levels in patients with end-stage renal disease incident to hemodialysis (HD) at a large, integrated health-care delivery system in Southern California. DESIGN: Retrospective cohort study. SUBJECTS: A total of 5,778 adult patients who initiated HD at our institution between January 1, 2007 and June 30, 2013. MAIN OUTCOME MEASURES: Unadjusted and adjusted time-averaged serum phosphorus levels and actual phosphorus levels over time. Phosphorus levels were also analyzed by repeated measures as a continuous measure and by phosphorus category. Baseline patient covariates included age, self-reported race, gender, cause of end-stage renal disease, and Charlson comorbidity index scores. Education and income level were estimated using geocoded data. RESULTS: A total of 68,372 phosphorus levels were available for 4,862 patients. Estimated annual family income fell below $40,001 in 66.1% of African Americans (AAs) and 62.7% of Hispanics compared with 43.5% of Asians and 43.7% of whites, P < .0001. Educational level fell into the highest category for whites (70.8%) compared with AA (44.8%) or Hispanic (30.5%) patients, P < .0001. Adjusted time-averaged phosphorus levels were lower among Hispanics (4.33 mg/dL, 95% confidence interval [CI] 4.27-4.40) compared with Asian (4.54 mg/dL, 95% CI 4.45-4.64, P < .001) and white patients (4.48 mg/dL, 95% CI 4.43-4.54, P < .001) but similar to AA patients. Asian patients experienced a significant increase in phosphorus levels over time (0.11 mg/dL per year, P < .0001). There were no significant effects of race, time, or race by time interactions in the unadjusted and adjusted categorical analyses of phosphorus levels. CONCLUSIONS: Our findings suggest that serum phosphorus levels are similar among HD patients, irrespective of race or socioeconomic status.

Quadrivalent Human Papillomavirus Vaccine Initiation in Boys Before and Since Routine Use: Southern California, 2009-2013.

OBJECTIVES: We examined the trends and correlates of quadrivalent human papillomavirus vaccine (HPV4) initiation in insured boys during the periods before and after routine use recommendation. METHODS: We grouped data from electronic medical records of boys aged 9 to 17 years from the Kaiser Permanente Southern California prepaid health plan into 3 open cohorts: permissive use: 2009 to 2010; anal cancer indication added: 2010 to 2011; and routine use: 2011 to 2013. We estimated adjusted risk ratios (ARRs) between demographics and vaccination initiation using Poisson regression. RESULTS: HPV4 initiation increased across cohorts--1.6%, 3.4%, and 18.5%--with the greatest increase among boys aged 11 to 12 years in cohort 3. Initiation was associated with receiving influenza vaccination in the previous year in all cohorts (cohort 3: ARR = 1.48; 95% confidence interval [CI] = 1.46, 1.51) and with non-White race/ethnicity following routine recommendation (cohort 3, non-Hispanic Black: ARR = 1.18; 95% CI = 1.08, 1.30; Hispanic: ARR = 1.23; 95% CI = 1.17, 1.29; Asian/Pacific Islanders: ARR = 1.16; 95% CI = 1.11, 1.20). CONCLUSIONS: Routine use recommendation increased the uptake of HPV4 in boys. System-level interventions to encourage providers to routinely recommend HPV4 vaccination may help increase HPV4 uptake in boys.

Survival of propensity matched incident peritoneal and hemodialysis patients in a United States health care system.

We sought to compare survival among incident peritoneal dialysis (PD) patients to matched hemodialysis (HD) patients who received pre-dialysis care, including permanent dialysis access placement. Patients starting PD were propensity matched to those starting HD. HD patients who used a central venous catheter during the first 90 days of dialysis were excluded. Stratified Cox proportional hazards models were used to compare patient survival using both intent-to-treat and as-treated analyses. In the intent-to-treat analysis, patients were followed from the date of first dialysis until death and censored at the earliest of the following: renal transplantation, death, renal recovery, loss to follow-up or study end. In the as-treated analysis, patients were also censored at the time of modality change. A total of 1003 matched pairs were obtained from 11,301 incident patients (10,298 HD and 1003 PD). The cumulative hazard ratio for death at one year was 2.38 (95% CI 1.68-3.40) and 2.10 (1.50-2.94) for HD relative to PD patients in the as-treated and intent-to-treat analyses, respectively. The cumulative risk of death, as estimated by the cumulative hazard ratio, favored PD for almost up to 3 years of follow-up in the as-treated analysis and nearly 2 years of follow-up in the intent-to-treat analysis with no differences thereafter. The higher adjusted rate of death observed for HD patients cannot be attributed to initial use of central venous catheters or lack of pre-dialysis care.

Adverse childhood experiences screening in healthcare settings: A focus on pediatric primary care.

BACKGROUND: Adverse Childhood Experiences (ACEs) screening in healthcare settings is emerging as one of the tangible responses to address the consistent evidence linking ACEs with health. Kaiser Permanente Southern California (KPSC) began ACEs screening in pediatric primary care in 2018 and has developed screening and referral processes based on continued feedback from stakeholders as well as data driven assessment. OBJECTIVE: We give an overview of the state of ACEs screening in pediatric healthcare settings, challenges facing pediatric providers, and suggestions to address them. We then describe the development of our ACEs screening and referral process within KPSC as an example of how a large healthcare system has implemented and adapted ACEs screening from pilot testing, to phased expansion, to complete implementation. PARTICIPANTS AND SETTING: Children aged 2-18 years old who were members of KPSC 2018-2023. RESULTS: We present data on the tailored screening and referral workflows we have developed, rates of positive screens and referrals, and how the initiation of ACEs screening may affect the rates of visit to behavioral health as a treatment option. We also integrate qualitative data to demonstrate the perspective of parents, with the goal of understanding what might help or hinder receipt of behavioral health treatment after ACEs screening. CONCLUSIONS: We close with future directions for ACEs screening in healthcare settings and considerations for pediatric healthcare providers who may want to begin ACEs screening or adapt their screening and referral processes.

Prevalence of Adolescents Meeting Criteria for Metabolic and Bariatric Surgery.

BACKGROUND AND OBJECTIVES: The American Academy of Pediatrics endorses metabolic and bariatric surgery (MBS) as a safe and effective treatment of severe obesity in children with class 3 obesity or with class 2 obesity and qualifying comorbidities. The study objective was to determine eligibility and characteristics of adolescents who qualify for MBS based on American Academy of Pediatrics guidelines. METHODS: This retrospective cohort study analyzed electronic health record data of 603 051 adolescents aged 13 to 17 years between January 1, 2018, and December 31, 2021. Centers for Disease Control and Prevention criteria were used to define obesity classes 2 and 3. Multivariable logistic regression was used to evaluate the factors associated with meeting MBS eligibility criteria. RESULTS: Of the 603 041 adolescents evaluated, 22.2% had obesity (12.9% class 1, 5.4% class 2, and 3.9% class 3). The most frequently diagnosed comorbid conditions were gastroesophageal reflux disease (3.2%), hypertension (0.5%), and nonalcoholic fatty liver disease (0.5%). Among adolescents with class 2 obesity, 9.1% had 1 or more comorbidities qualifying for MBS, and 4.4% of all adolescents met the eligibility criteria for MBS. In multivariable modeling, males, Black and Hispanic adolescents, and those living in more deprived neighborhoods were more likely to meet MBS eligibility criteria. CONCLUSIONS: Overall, 1 in 23 adolescents met the eligibility criteria for MBS. Demographic and social determinants were associated with a higher risk for meeting these criteria. The study suggests that the health care system may face challenges in accommodating the demand for MBS among eligible adolescents.

The Effect of City-Level Sugar-Sweetened Beverage Taxes on Longitudinal HbA1c and Incident Diabetes in Adults With Prediabetes.

OBJECTIVE: Prediabetes, which is a condition characterized by higher-than-normal blood glucose levels that are under the threshold for diabetes, impacts over one-third of U.S. adults. Excise taxes on sugar-sweetened beverages (SSBs) are a proposed policy intervention to lower population consumption of SSBs and generate revenue to support health-related programs, thus potentially delaying or preventing the development of diabetes in individuals with prediabetes. We leveraged data from Kaiser Permanente in California to examine the impact of SSB taxes in California on individual-level mean HbA1c levels and rates of incident diabetes. RESEARCH DESIGN AND METHODS: We compared two outcomes, mean HbA1c levels and rates of incident diabetes, among a matched cohort of adults with prediabetes who lived and did not live in SSB excise tax cities, using outcomes collected in the 6 years prior and 4 years following SSB tax implementation. We used multivariable linear mixed effects models to analyze longitudinal mean HbA1c and discrete-time survival models for incident diabetes. RESULTS: We included 68,658 adults in the analysis. In adjusted models, longitudinal mean HbA1c was 0.007% (95% CI 0.002, 0.011) higher in the tax cities compared with control individuals; while the estimated difference was statistically significant, it was not clinically significant (HbA1c <0.5%). There was no significant difference in the risk of incident diabetes between individuals living in tax and control cities. CONCLUSIONS: We found no clinically significant association between SSB taxes and either longitudinal mean HbA1c or incident diabetes among adults with prediabetes in the 4 years following SSB tax implementation.

Quadrivalent human papillomavirus vaccine uptake in adolescent boys and maternal utilization of preventive care and history of sexually transmitted infections.

OBJECTIVES: We examined whether maternal utilization of preventive care and history of sexually transmitted infections (STIs) predicted quadrivalent human papillomavirus vaccine (HPV4) uptake among adolescent boys 1 year following the recommendation for permissive use of HPV4 for males. METHODS: We linked maternal information with electronic health records of 254 489 boys aged 9 to 17 years who enrolled in Kaiser Permanente Southern California health plan from October 21, 2009, through December 21, 2010. We used multivariable Poisson regression with robust error variance to examine whether HPV4 initiation was associated with maternal uptake of influenza vaccine, Papanicolaou (Pap) screening, and history of STIs. RESULTS: We identified a modest but statistically significant association between initiation of HPV4 series and maternal receipt of influenza vaccine (rate ratio [RR] = 1.16; 95% confidence interval [CI] = 1.07, 1.26) and Pap screening (RR = 1.13; 95% CI = 1.01, 1.26). Boys whose mothers had a history of genital warts were more likely to initiate HPV4 (RR = 1.47; 95% CI = 0.93, 2.34), although the association did not reach statistical significance (P = .1). CONCLUSIONS: Maternal utilization of preventive care and history of genital warts may influence HPV4 uptake among adolescent boys. The important role of maternal health characteristics and health behaviors needs be considered in intervention efforts to increase vaccine uptake among boys.

Association of High Normal Body Weight in Youths With Risk of Hypertension.

Importance: Ample evidence links obesity to hypertension in youths. However, the association of high normal body mass index (BMI) with obesity and the interaction with different weight trajectories are not well understood. Objective: To examine the hypertension risk associated with high normal BMI for age and different weight trajectories in youths. Design, Setting, and Participants: This retrospective cohort study assessed 801 019 youths aged 3 to 17 years in an integrated health care system in Southern California from January 1, 2008, to February 28, 2015, with a maximum follow-up of 5 years from January 1, 2008, to February 28, 2020. Data analysis was performed from 2018 to 2022. Exposures: Youths were compared by first available (baseline) sex-specific BMI for age and change in the distance to the median BMI for age during the 5-year follow-up. Main Outcomes and Measures: Cox proportional hazards regression models with age as a time scale to assess hypertension risk (based on 2017 Blood Pressure Guidelines by the American Academy of Pediatrics from 3 consecutive independent visits), adjusted for sex, race and ethnicity, socioeconomic status, baseline year, and birth year. Results: A total of 801 019 youths (mean [SD] age, 9.4 [4.6] years; 409 167 [51.1%] female]; 59 399 [7.4%] Asian and Pacific Islanders, 65 712 [8.2%] Black, and 427 492 [53.4%] Hispanic) were studied. Compared with youths with a baseline BMI for age in the 40th to 59th percentiles, the adjusted hazard ratio (aHR) for hypertension within a maximum of 5 years was 1.26 (95% CI, 1.20-1.33) for youths between the 60th and 84th percentiles if they maintained their BMI for age. With every 1-unit annual increase in the distance to the median BMI for age, the aHR increased by 1.04 (95% CI, 1.04-1.05). The aHR was 4.94 (95% CI, 4.72-5.18) in youths with a baseline BMI for age in the 97th percentile or higher who maintained their body weight. Weight gain increased the risk associated with baseline BMI for age in the 97th percentile or higher with an aHR of 1.04 (95% CI, 1.04-1.05) per 1-unit annual increase in the distance to the median BMI for age. The risk associated with weight change was higher in youths living with low to high normal weight and overweight than in youths living with severe obesity. Conclusions and Relevance: In this cohort study of youths, high normal body weight above the 60th percentile of BMI for age was associated with increased risk of hypertension. Weight gain was associated with further increases in hypertension risk. Further research is needed to evaluate the wide range of body weight considered normal in youths and the health risks associated with high normal weight.

Disparities in weight changes during the COVID-19 pandemic-related lockdown in youths.

OBJECTIVE: This study evaluates whether changes in weight among school-aged youth in California due to the COVID-19 lockdown vary by social constructs of race/ethnicity and associated social factors. METHODS: Including 160,472 youth aged 5 to 17 years enrolled at Kaiser Permanente Southern California, mixed effects models stratified by age group were fitted to estimate changes in distance from the median BMI-for-age from March 2020 to January 2021 (lockdown) compared with the same period before the pandemic. RESULTS: Excess pandemic weight gain was higher among Black and Hispanic youth aged 5 to 17 years than among White and Asian youth; this difference was most pronounced in those aged 5 to 11 years. In youth aged 5 to 11 years, the distance from the median BMI-for-age increased by 1.72 kg/m2 (95% CI: 1.61-1.84) in Hispanic and 1.70 kg/m2 (95% CI: 1.47-1.94) in Black youth during the lockdown compared with 1.16 kg/m2 (95% CI: 1.02-1.29) in non-Hispanic White youth. The excess weight gain was also higher in youth with fewer neighborhood parks and those with state-subsidized health insurance. CONCLUSIONS: The COVID-19 pandemic lockdown led to a gain of excess body weight, particularly for Black and Hispanic youth; this weight gain varied by social factors associated with race and ethnicity.

Higher body mass index after intrapartum antibiotic exposure in children persists over 10-years.

Exposure to intrapartum antibiotic prophylaxis to reduce perinatal group B streptococcal disease was associated with increased childhood body mass index (BMI) persisting to age 10 years compared to no exposure (Δ BMI at 10 years: vaginal delivery 0.14 kg/m2 , caesarean 0.40 kg/m2 ).

Classification system of graft tears following superior capsule reconstruction.

OBJECTIVE: Superior capsule reconstruction (SCR) is a treatment option for irreparable massive rotator cuff tears (MRCT). The purpose of this study is to describe a classification system for graft integrity and tear location. METHODS: Patients who underwent SCR at a single institution were included. Pre-operative age, gender, prior surgery, Hamada grade, and Goutallier stage were recorded. An MRI was performed postoperatively to assess graft integrity and tear location. RESULTS: 53 patients met inclusion criteria. Mean age was 60.1 ± 7.9 years. A post-operative MRI was performed in 42 (80%) patients at a mean of 14 ± 7 months (range, 6-40 months). MRIs demonstrated an intact graft in 16 (38%) shoulders. Of the 26 graft tears, 14 (54%) were from the glenoid, 5 (19%) mid-substance, 6 (23%) from the tuberosity, and 1 (3.8%) had complete graft absence. CONCLUSION: Graft tears are common following SCR. We describe four different graft tear locations and submit a classification system that can be used in future studies to better compare outcomes based on graft integrity and tear location. Clinical correlation with graft integrity and graft tear location needs to be further investigated.

Near-roadway air pollution associated with COVID-19 severity and mortality - Multiethnic cohort study in Southern California.

BACKGROUND: Air pollution exposure has been associated with increased risk of COVID-19 incidence and mortality by ecological analyses. Few studies have investigated the specific effect of traffic-related air pollution on COVID-19 severity. OBJECTIVE: To investigate the associations of near-roadway air pollution (NRAP) exposure with COVID-19 severity and mortality using individual-level exposure and outcome data. METHODS: The retrospective cohort includes 75,010 individuals (mean age 42.5 years, 54% female, 66% Hispanic) diagnosed with COVID-19 at Kaiser Permanente Southern California between 3/1/2020-8/31/2020. NRAP exposures from both freeways and non-freeways during 1-year prior to the COVID-19 diagnosis date were estimated based on residential address history using the CALINE4 line source dispersion model. Primary outcomes include COVID-19 severity defined as COVID-19-related hospitalizations, intensive respiratory support (IRS), intensive care unit (ICU) admissions within 30 days, and mortality within 60 days after COVID-19 diagnosis. Covariates including socio-characteristics and comorbidities were adjusted for in the analysis. RESULT: One standard deviation (SD) increase in 1-year-averaged non-freeway NRAP (0.5 ppb NOx) was associated with increased odds of COVID-19-related IRS and ICU admission [OR (95% CI): 1.07 (1.01, 1.13) and 1.11 (1.04, 1.19) respectively] and increased risk of mortality (HR = 1.10, 95% CI = 1.03, 1.18). The associations of non-freeway NRAP with COVID-19 outcomes were largely independent of the effect of regional fine particulate matter and nitrogen dioxide exposures. These associations were generally consistent across age, sex, and race/ethnicity subgroups. The associations of freeway and total NRAP with COVID-19 severity and mortality were not statistically significant. CONCLUSIONS: Data from this multiethnic cohort suggested that NRAP, particularly non-freeway exposure in Southern California, may be associated with increased risk of COVID-19 severity and mortality among COVID-19 infected patients. Future studies are needed to assess the impact of emerging COVID-19 variants and chemical components from freeway and non-freeway NRAP.