Changes in leukocyte telomere length among children with obesity participating in a behavioural weight control program.

OBJECTIVE: To examine changes in leukocyte telomere length (LTL) during and after a behavioural weight control program for children with obesity. METHODS: We measured LTL among a cohort of 158 children 8-12 years of age with a body mass index greater than or equal to the 95th percentile for age and sex. Children were 55% female, 29% white, 52% Latinx, 8% Asian and 11% Pacific Islander, other or multiethnic. All children participated in a 6-month, family-based, group behavioural weight control program and were assessed before treatment, after treatment and 1 year after the end of treatment. To test the sample population slope of LTL over the intervention and maintenance time periods, we fit spline mixed-effect regression models. RESULTS: LTL increased an average of 0.09 T/S units per year (95% confidence interval [CI] 0.04 to 0.13; p = 0.0001) during the weight control program intervention period, followed by an average decline of -0.05 T/S units per year (95% CI -0.08 to -0.03; p < 0.0001) during the 1 year of follow-up after the completion of the intervention. Among 26 social, psychological, behavioural and physiological factors we examined, we did not find any predictors of these changes. CONCLUSIONS: LTL increased in response to a behavioural weight control program among children with obesity, suggesting an impact on biological health and cellular aging from participation in a behavioural weight control intervention. LTL may be a useful biomarker for assessing changes in response to behavioural interventions.

COVIDNearTerm: A simple method to forecast COVID-19 hospitalizations.

Introduction: COVID-19 has caused tremendous death and suffering since it first emerged in 2019. Soon after its emergence, models were developed to help predict the course of various disease metrics, and these models have been relied upon to help guide public health policy. Methods: Here we present a method called COVIDNearTerm to "forecast" hospitalizations in the short term, two to four weeks from the time of prediction. COVIDNearTerm is based on an autoregressive model and utilizes a parametric bootstrap approach to make predictions. It is easy to use as it requires only previous hospitalization data, and there is an open-source R package that implements the algorithm. We evaluated COVIDNearTerm on San Francisco Bay Area hospitalizations and compared it to models from the California COVID Assessment Tool (CalCAT). Results: We found that COVIDNearTerm predictions were more accurate than the CalCAT ensemble predictions for all comparisons and any CalCAT component for a majority of comparisons. For instance, at the county level our 14-day hospitalization median absolute percentage errors ranged from 16 to 36%. For those same comparisons, the CalCAT ensemble errors were between 30 and 59%. Conclusion: COVIDNearTerm is a simple and useful tool for predicting near-term COVID-19 hospitalizations.

Cardiovascular and Cerebrovascular Disease Mortality in Asian American Subgroups.

BACKGROUND: Asian American individuals comprise the fastest-growing race and ethnic group in the United States. Certain subgroups may be at disproportionately high cardiovascular risk. This analysis aimed to identify cardiovascular and cerebrovascular disease mortality trends in Asian American subgroups. METHODS: Age-standardized mortality rates (ASMR), average annual percent change of ASMR calculated by regression, and proportional mortality ratios of ischemic heart disease, heart failure, and cerebrovascular disease were calculated by sex in non-Hispanic Asian American subgroups (Chinese, Filipino, Asian Indian, Japanese, Korean, and Vietnamese), non-Hispanic White, and Hispanic individuals from US death certificates, 2003 to 2017. RESULTS: Among 618 004 non-Hispanic Asian American, 30 267 178 non-Hispanic White, and 2 292 257 Hispanic deaths from all causes, ASMR from ischemic heart disease significantly decreased in all subgroups of Asian American women and in non-Hispanic White and Hispanic women; significantly decreased in Chinese, Filipino, Japanese, and Korean men and non-Hispanic White and Hispanic men and remained stagnant in Asian Indian and Vietnamese men. The highest 2017 ASMR from ischemic heart disease among Asian American decedents was in Asian Indian women (77 per 100 000) and men (133 per 100 000). Heart failure ASMR remained stagnant in Chinese, Korean, and non-Hispanic White women, and Chinese and Vietnamese men. Heart failure ASMR significantly increased in both sexes in Filipino, Asian Indian, and Japanese individuals, Vietnamese women, and Korean men, with highest 2017 ASMR among Asian American subgroups in Asian Indian women (14 per 100 000) and Asian Indian men (15 per 100 000). Cerebrovascular disease ASMR decreased in Chinese, Filipino, and Japanese women and men between 2003 and 2017, and remained stagnant in Asian Indian, Korean, and Vietnamese women and men. The highest cerebrovascular disease ASMR among Asian American subgroups in 2017 was in Vietnamese women (46 per 100 000) and men (47 per 100 000). CONCLUSIONS: There was heterogeneity in cardiovascular and cerebrovascular mortality among Asian American subgroups, with stagnant or increasing mortality trends in several subgroups between 2003 and 2017.

The impact of estradiol on pregnancy outcomes in letrozole-stimulated frozen embryo transfer cycles.

OBJECTIVE: To assess the impact of low estradiol (E2) levels in letrozole-stimulated frozen embryo transfer (FET) cycles on pregnancy and neonatal outcomes. DESIGN: Retrospective cohort. SETTING: University-affiliated fertility center. PATIENTS: All patients who underwent letrozole-stimulated FET cycles from January 2017 to April 2020 (n = 217). The "Low E2" group was defined as those with E2 serum levels on the day of trigger <10th percentile level (E2 <91.16 pg/mL, n = 22) and the "Normal E2" group was defined as those with E2 serum levels ≥10th percentile level (E2 ≥91.16 pg/mL, n = 195). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Pregnancy outcomes including rates of clinical pregnancy, clinical miscarriage, and live birth. Neonatal outcomes including gestational age at delivery, birth weight, and Apgar score. RESULTS: The mean ± SD estradiol level was 66.8 ± 14.8 pg/mL for the "Low E2" group compared with 366.3 ± 322.1 pg/mL for the "Normal E2" group. There were otherwise no substantial differences in cycle characteristics such as endometrial thickness on the day of ovulation trigger and progesterone levels in early pregnancy. The "Low E2" group had a significantly higher clinical miscarriage rate (36.4% vs. 8.8%, adjusted odds ratio 8.06) and lower live birth rate (31.8% vs. 57.9%, adjusted odds ratio 0.28). Neonatal outcomes such as gestational age at delivery, mean birth weight, Apgar scores, and incidence of newborn complications were not clinically different between the groups. CONCLUSION: Low E2 levels were associated with a significantly higher miscarriage rate and lower live birth rate, suggesting that E2 levels in the follicular phase may have an effect on cycle outcomes. Given the rise in use of FET, further studies are needed to confirm our findings and understand the mechanisms.

A community-based, multi-level, multi-setting, multi-component intervention to reduce weight gain among low socioeconomic status Latinx children with overweight or obesity: The Stanford GOALS randomised controlled trial.

BACKGROUND: There are few long-term studies of interventions to reduce in low socioeconomic status children with overweight or obesity. The Stanford GOALS trial evaluated a 3-year, community-based, multi-level, multi-setting, multi-component (MMM) systems intervention, to reduce weight gain among low socioeconomic status, Latinx children with overweight or obesity. METHODS: We did a two-arm, parallel group, randomised, open-label, active placebo-controlled trial with masked assessment over 3 years. Families from low-income, primarily Latinx communities in Northern California, CA, USA, with 7-11-year-old children with overweight or obesity were randomly assigned to a MMM intervention or a Health Education (HE) comparison intervention. The MMM intervention included home environment changes and behavioural counselling, community after school team sports, and reports to primary health-care providers. The primary outcome was child BMI trajectory over three years. Secondary outcomes included one- and two-year changes in BMI. This trial is registered with ClinicalTrials.govNCT01642836. FINDINGS: Between July 13, 2012, and Oct 3, 2013, 241 families were recruited and randomly assigned to MMM (n=120) or HE (n=121). Children's mean age was 9·5 (SD 1·4) years, 134 (56%) were female and 107 (44%) were male, and 236 (98%) were Latinx. 238 (99%) children participated in year 1, 233 (97%) in year 2, and 227 (94%) in year 3 of follow-up assessments. In intention-to-treat analysis, over 3 years, the difference between intervention groups in BMI trajectory was not significant (mean adjusted difference -0·25 [95% CI -0·90 to 0·40] kg/m2; Cohen's d=0.10; p=0·45). Children in the MMM intervention group gained less BMI over 1 year than did children in the HE intervention group (-0·73 [-1·07 to -0·39] kg/m2, d=0.55); the same was true over 2 years (-0·63 [-1·13 to -0·14] kg/m2; d =0.33). No differential adverse events were observed. INTERPRETATION: The MMM intervention did not reduce BMI gain versus HE over 3 years but the effects over 1 and 2 years in this rigorous trial show the promise of this systems intervention approach for reducing weight gain and cardiometabolic risk factors in low socioeconomic status communities. FUNDING: US National Institutes of Health.

Safety of Plasma Infusions in Parkinson's Disease.

BACKGROUND: Young plasma infusions have emerged as a potential treatment for neurodegenerative disease, and convalescent plasma therapy has been used safely in the management of viral pandemics. However, the effect of plasma therapy in Parkinson's disease (PD) is unknown. OBJECTIVES: The objective of this study was to determine the safety, tolerability, and feasibility of plasma infusions in people with PD. METHODS: A total of 15 people with clinically established PD, at least 1 cognitive complaint, and on stable therapy received 1 unit of young fresh frozen plasma twice a week for 4 weeks. Assessments and adverse effects were performed/reported on and off therapy at baseline, immediately after, and 4 weeks after the infusions ended. Adverse effects were also assessed during infusions. The primary outcomes were safety, tolerability, and feasibility. Exploratory outcomes included Unified Parkinson's Disease Rating Scale Part III off medication, neuropsychological battery, Parkinson's Disease Questionnaire-39, inflammatory markers (tumor necrosis factor-α, interleukin-6), uric acid, and quantitative kinematics. RESULTS: Adherence rate was 100% with no serious adverse effects. There was evidence of improvement in phonemic fluency (P = 0.002) and in the Parkinson's Disease Questionnaire-39 stigma subscore (P = 0.013) that were maintained at the delayed evaluation. Elevated baseline tumor necrosis factor-α levels decreased 4 weeks after the infusions ended. CONCLUSIONS: Young fresh frozen plasma was safe, feasible, and well tolerated in people with PD, without serious adverse effects and with preliminary evidence for improvements in phonemic fluency and stigma. The results of this study warrant further therapeutic investigations in PD and provide safety and feasibility data for plasma therapy in people with PD who may be at higher risk for severe complications of COVID-19. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Sex differences in symptom presentation and functional outcomes: a pilot study in a matched sample of veterans with mild TBI.

Primary Objective: Research focused on mild traumatic brain injury in active military and veteran populations details the psychological, neurological and functional outcomes of mTBI, in a primarily male (~95%) cohort. This may misrepresent female symptoms and outcomes. Here we assess for genuine sex differences in symptom presentation and functional outcomes.Research Design: We used matched pairs to preclude potential sex bias in outcome data.Methods and Procedures: We matched 49 female/male pairs on; 1) mechanism of injury, 2) time from injury to assessment and 3) age at assessment. Statistics were t-tests, chi-square, correlations and post hoc linear regression.Main outcomes and results: Outcome assessment revealed four significant (p < .05) sex differences; Living situation, Marital status, Vocation and Branch of service. Only the Neurobehavioral Symptom Inventory (NSI) composite cognitive domain factor was significantly different between females (mean: 10.26) and males (mean: 7.58). Linear regression confirmed a significant effect of sex for the cognitive composite (p = .002).Conclusion: We conclude that sex has a moderate effect on mTBI post-concussive symptom presentation. The significant sex difference in the NSI cognitive domain characterizes sex-related symptomology profiles providers can focus on for better rehabilitation management. Replication in the larger cohort would improve generalizability.Abbreviation: TBI: Traumatic Brain Injuries; mTBI: mild Traumatic Brain Injuries; OIF: Operation Iraqi Freedom; OEF: Operation Enduring Freedom; VA: Veterans Affairs Health Care System; PSC: Polytrauma System of Care; PRC: Polytrauma Rehabilitation Center; PTRP: Polytrauma Transitional Rehabilitation Program; PNS: Polytrauma Network Site; PTSD: Post Traumatic Stress Disorder; DoD: Department of Defense; NSI: Neurobehavioral Symptom Inventory; LOC: loss of consciousness; AOC: alteration of consciousness; PTA: posttraumatic amnesia; CPRS: computerized patient record system; CTBIE: Comprehensive TBI Evaluation; OCD: obsessive compulsive disorder; ETOH: alcohol abuse.

QTc Prolongation and Risk of Torsades de Pointes in Hospitalized Pediatric Oncology Patients.

OBJECTIVE: To evaluate the prevalence of torsades de pointes and to identify risk factors associated with QTc prolongation of ≥500 milliseconds in hospitalized pediatric oncology patients. A QTc prolongation of ≥500 milliseconds is associated with higher mortality in hospitalized adults but has not been demonstrated in pediatrics. STUDY DESIGN: A single-center, retrospective review of all hospitalized oncology patients ≤21 years of age was performed from 2014 to 2016. Patients with long/short QT syndrome or a QRS interval of ≥120 ms were excluded. Rapid response events were reviewed to determine the prevalence of torsades. In patients with ECGs for review, data were compared between patients with a QTc of <500 and ≥500 ms via logistic regression. RESULTS: There were 1934 hospitalized patients included. Rapid response events occurred in 90 patients (4.7%) with 2 torsades events (0.1%). There were 1412 electrocardiograms performed in 287 unique patients (10.6 ± 6.3 years of age; 43% female). The mean QTc was 448 ± 31 ms; 25 patients (8.7%) had ≥1 ECG with a QTc of ≥500 ms. The prevalence of torsades was greater in patients with a QTc of ≥500 ms (8% vs 0%; P<.01). In multivariate analysis, factors associated with a QTc of ≥500 ms included female sex, (OR 2.95) and ≥2 QT-prolonging medications (OR, 2.95). CONCLUSIONS: The prevalence of torsades in hospitalized pediatric oncology patients was low (0.1%), although the risk was significantly greater in patients with a QTc of ≥500 ms. Routine monitoring of electrocardiograms and electrolytes is essential in patients with risk factors predisposing to QTc prolongation.

Maternal and neonatal outcomes associated with trophectoderm biopsy.

OBJECTIVE: To assess whether pregnancies achieved with trophectoderm biopsy for preimplantation genetic testing (PGT) have different risks of adverse obstetric and neonatal outcomes compared with pregnancies achieved with IVF without biopsy. DESIGN: Observational cohort. SETTING: University-affiliated fertility center. PATIENT(S): Pregnancies achieved via IVF with PGT (n = 177) and IVF without PGT (n = 180) that resulted in a live birth. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Maternal outcomes including preeclampsia and placenta previa and neonatal outcomes including birth weight and birth defects. RESULT(S): There was a statistically significant increase in the risk of preeclampsia among IVF+PGT pregnancies compared with IVF without PGT pregnancies, with an incidence of 10.5% versus 4.1% (adjusted odds ratio [aOR] = 3.02; 95% confidence interval [95% CI], 1.10, 8.29). The incidence of placenta previa was 5.8% in IVF+PGT pregnancies versus 1.4% in IVF without PGT pregnancies (aOR = 4.56; 95% CI, 0.93, 22.44). Similar incidences of gestational diabetes, preterm premature rupture of membranes, and postpartum hemorrhage were observed. IVF+PGT and IVF without PGT neonates did not have a significantly different gestational age at delivery or rate of preterm birth, low birth weight, neonatal intensive care unit admission, neonatal morbidities, or birth defects. All trends, including the significantly increased risk of preeclampsia in IVF+PGT pregnancies, persisted upon stratification of analysis to only singleton live births. CONCLUSION(S): To date, this is the largest and most extensively controlled study examining maternal and neonatal outcomes after trophectoderm biopsy. There was a statistically significant three-fold increase in the odds of preeclampsia associated with trophectoderm biopsy. Given the rise in PGT use, further investigation is warranted.

Dialysis versus Medical Management at Different Ages and Levels of Kidney Function in Veterans with Advanced CKD.

Background Appropriate patient selection and optimal timing of dialysis initiation among older adults with advanced CKD are uncertain. We determined the association between dialysis versus medical management and survival at different ages and levels of kidney function.Methods We assembled a nationally representative 20% sample of United States veterans with eGFR<30 ml/min per 1.73 m2 between 2005 and 2010 (n=73,349), with follow-up through 2012. We used an extended Cox model to determine associations among the time-varying exposures, age (<65, 65-74, 75-84, and ≥85 years), eGFR (<6, 6-<9, 9-<12, 12-<15, and 15-<29 ml/min per 1.73 m2), and provision of dialysis, and survival.Result Over the mean±SEM follow-up of 3.4±2.2 years, 15% of patients started dialysis and 52% died. The eGFR at which dialysis, compared with medical management, associated with lower mortality varied by age (P<0.001). For patients aged <65, 65-74, 75-84, and ≥85 years, dialysis associated with lower mortality for those with eGFR not exceeding 6-<9, <6, 9-<12, and 9-<12 ml/min per 1.73 m2, respectively. Dialysis initiation at eGFR<6 ml/min per 1.73 m2 associated with a higher median life expectancy of 26, 25, and 19 months for patients aged 65, 75, and 85 years, respectively. When dialysis was initiated at eGFR 9-<12 ml/min per 1.73 m2, the estimated difference in median life expectancy was <1 year for these patients.Conclusions Provision of dialysis at higher levels of kidney function may extend survival for some older patients.

Mortality outcomes for Chinese and Japanese immigrants in the USA and countries of origin (Hong Kong, Japan): a comparative analysis using national mortality records from 2003 to 2011.

BACKGROUND: With immigration and minority populations rapidly growing in the USA, it is critical to assess how these populations fare after immigration, and in subsequent generations. Our aim is to compare death rates and cause of death across foreign-born, US-born and country of origin Chinese and Japanese populations. METHODS: We analysed all-cause and cause-specific age-standardised mortality rates and trends using 2003-2011 US death record data for Chinese and Japanese decedents aged 25 or older by nativity status and sex, and used the WHO Mortality Database for Hong Kong and Japan decedents in the same years. Characteristics such as age at death, absolute number of deaths by cause and educational attainment were also reported. RESULTS: We examined a total of 10 458 849 deaths. All-cause mortality was highest in Hong Kong and Japan, intermediate for foreign-born, and lowest for US-born decedents. Improved mortality outcomes and higher educational attainment among foreign-born were observed compared with developed Asia counterparts. Lower rates in US-born decedents were due to decreased cancer and communicable disease mortality rates in the US heart disease mortality was either similar or slightly higher among Chinese-Americans and Japanese-Americans compared with those in developed Asia counterparts. CONCLUSIONS: Mortality advantages in the USA were largely due to improvements in cancer and communicable disease mortality outcomes. Mortality advantages and higher educational attainments for foreign-born populations compared with developed Asia counterparts may suggest selective migration. Findings add to our limited understanding of the racial and environmental contributions to immigrant health disparities.

Leading Causes of Death among Asian American Subgroups (2003-2011).

BACKGROUND: Our current understanding of Asian American mortality patterns has been distorted by the historical aggregation of diverse Asian subgroups on death certificates, masking important differences in the leading causes of death across subgroups. In this analysis, we aim to fill an important knowledge gap in Asian American health by reporting leading causes of mortality by disaggregated Asian American subgroups. METHODS AND FINDINGS: We examined national mortality records for the six largest Asian subgroups (Asian Indian, Chinese, Filipino, Japanese, Korean, Vietnamese) and non-Hispanic Whites (NHWs) from 2003-2011, and ranked the leading causes of death. We calculated all-cause and cause-specific age-adjusted rates, temporal trends with annual percent changes, and rate ratios by race/ethnicity and sex. Rankings revealed that as an aggregated group, cancer was the leading cause of death for Asian Americans. When disaggregated, there was notable heterogeneity. Among women, cancer was the leading cause of death for every group except Asian Indians. In men, cancer was the leading cause of death among Chinese, Korean, and Vietnamese men, while heart disease was the leading cause of death among Asian Indians, Filipino and Japanese men. The proportion of death due to heart disease for Asian Indian males was nearly double that of cancer (31% vs. 18%). Temporal trends showed increased mortality of cancer and diabetes in Asian Indians and Vietnamese; increased stroke mortality in Asian Indians; increased suicide mortality in Koreans; and increased mortality from Alzheimer's disease for all racial/ethnic groups from 2003-2011. All-cause rate ratios revealed that overall mortality is lower in Asian Americans compared to NHWs. CONCLUSIONS: Our findings show heterogeneity in the leading causes of death among Asian American subgroups. Additional research should focus on culturally competent and cost-effective approaches to prevent and treat specific diseases among these growing diverse populations.

Cardiovascular disease mortality in Asian Americans.

BACKGROUND: Asian Americans are a rapidly growing racial/ethnic group in the United States. Our current understanding of Asian-American cardiovascular disease mortality patterns is distorted by the aggregation of distinct subgroups. OBJECTIVES: The purpose of the study was to examine heart disease and stroke mortality rates in Asian-American subgroups to determine racial/ethnic differences in cardiovascular disease mortality within the United States. METHODS: We examined heart disease and stroke mortality rates for the 6 largest Asian-American subgroups (Asian Indian, Chinese, Filipino, Japanese, Korean, and Vietnamese) from 2003 to 2010. U.S. death records were used to identify race/ethnicity and cause of death by International Classification of Diseases-10th revision coding. Using both U.S. Census data and death record data, standardized mortality ratios (SMRs), relative SMRs (rSMRs), and proportional mortality ratios were calculated for each sex and ethnic group relative to non-Hispanic whites (NHWs). RESULTS: In this study, 10,442,034 death records were examined. Whereas NHW men and women had the highest overall mortality rates, Asian Indian men and women and Filipino men had greater proportionate mortality burden from ischemic heart disease. The proportionate mortality burden of hypertensive heart disease and cerebrovascular disease, especially hemorrhagic stroke, was higher in every Asian-American subgroup compared with NHWs. CONCLUSIONS: The heterogeneity in cardiovascular disease mortality patterns among diverse Asian-American subgroups calls attention to the need for more research to help direct more specific treatment and prevention efforts, in particular with hypertension and stroke, to reduce health disparities for this growing population.

Impact of San Francisco's toy ordinance on restaurants and children's food purchases, 2011-2012.

INTRODUCTION: In 2011, San Francisco passed the first citywide ordinance to improve the nutritional standards of children's meals sold at restaurants by preventing the giving away of free toys or other incentives with meals unless nutritional criteria were met. This study examined the impact of the Healthy Food Incentives Ordinance at ordinance-affected restaurants on restaurant response (eg, toy-distribution practices, change in children's menus), and the energy and nutrient content of all orders and children's-meal-only orders purchased for children aged 0 through 12 years. METHODS: Restaurant responses were examined from January 2010 through March 2012. Parent-caregiver/child dyads (n = 762) who were restaurant customers were surveyed at 2 points before and 1 seasonally matched point after ordinance enactment at Chain A and B restaurants (n = 30) in 2011 and 2012. RESULTS: Both restaurant chains responded to the ordinance by selling toys separately from children's meals, but neither changed their menus to meet ordinance-specified nutrition criteria. Among children for whom children's meals were purchased, significant decreases in kilocalories, sodium, and fat per order were likely due to changes in children's side dishes and beverages at Chain A. CONCLUSION: Although the changes at Chain A did not appear to be directly in response to the ordinance, the transition to a more healthful beverage and default side dish was consistent with the intent of the ordinance. Study results underscore the importance of policy wording, support the concept that more healthful defaults may be a powerful approach for improving dietary intake, and suggest that public policies may contribute to positive restaurant changes.

Secondhand smoke exposure in the nonsmoking section: how much protection?

INTRODUCTION: Secondhand smoke (SHS) exposure continues to be a problem in bars and restaurants where smoking is permitted. This study measures the relative SHS exposure reduction in nonsmoking sections of establishments that allow some smoking. METHODS: Measurements were conducted simultaneously in the smoking and nonsmoking sections of 14 Minnesota hospitality venues. All of the 16 two-hr visits included photometer measurements of fine particles (PM2.5) and 12 of the visits also included measurements of 4 gas-phase tracers of SHS. RESULTS: The median ratio of nonsmoking/smoking section PM2.5 concentrations was 0.65 with an interquartile range (IQR) of 0.49-0.72. Measurements conducted after implementation of a smoking ban at 13 of the venues resulted in a smoking section PM2.5 post-ban/pre-ban ratio of 0.06 (IQR = 0.02-0.16). The median nonsmoking/smoking section ratios for gas-phase compound were 0.67 (IQR = 0.35-0.78) for pyridine, 0.52 (IQR = 0.30-0.70) for pyrrole, 0.43 (IQR = 0.35-0.84) for 3-EP, and 0.27 (IQR = 0.16-0.47) for nicotine. These results are consistent with the expectations of differential removal: the lowest ratios are for the least volatile, most strongly sorbing gases and the highest ratios for less sorbing gases and PM2.5. CONCLUSIONS: Designated nonsmoking sections in establishments that allow some smoking resulted in a median PM2.5 reduction of 35% compared with a 94% reduction after a smoking ban. The only adequate protection from cigarette smoke exposure is to eliminate smoking in indoor spaces.

Change in indoor particle levels after a smoking ban in Minnesota bars and restaurants.

BACKGROUND: Smoking bans in bars and restaurants have been shown to improve worker health and reduce hospital admissions for acute myocardial infarction. Several studies have also reported improved indoor air quality, although these studies generally used single visits before and after a ban for a convenience sample of venues. PURPOSE: The primary objective of this study was to provide detailed time-of-day and day-of-week secondhand smoke-exposure data for representative bars and restaurants in Minnesota. METHODS: This study improved on previous approaches by using a statistically representative sample of three venue types (drinking places, limited-service restaurants, and full-service restaurants), conducting repeat visits to the same venue prior to the ban, and matching the day of week and time of day for the before- and after-ban monitoring. The repeat visits included laser photometer fine particulate (PM2.5) concentration measurements, lit cigarette counts, and customer counts for 19 drinking places, eight limited-service restaurants, and 35 full-service restaurants in the Minneapolis/St. Paul metropolitan area. The more rigorous design of this study provides improved confidence in the findings and reduces the likelihood of systematic bias. RESULTS: The median reduction in PM2.5 was greater than 95% for all three venue types. Examination of data from repeated visits shows that making only one pre-ban visit to each venue would greatly increase the range of computed percentage reductions and lower the statistical power of pre-post tests. Variations in PM2.5 concentrations were found based on time of day and day of week when monitoring occurred. CONCLUSIONS: These comprehensive measurements confirm that smoking bans provide significant reductions in SHS constituents, protecting customers and workers from PM2.5 in bars and restaurants.