Examining reactivity to intensive longitudinal ecological momentary assessment: 12-month prospective study.

PURPOSE: To examine the association between intensive, longitudinal ecological momentary assessment (EMA) and self-reported eating behaviors. METHODS: Secondary analysis of the EMPOWER study-a 12-month observational study that examined the microprocesses of relapse following intentional weight loss using smartphone-administered EMA-was conducted. Participants were asked to complete four types of EMA surveys using a mobile app. For this analysis, only the number of completed random EMA surveys was used. Using linear mixed-effects modeling, we analyzed whether the number of completed random EMA surveys was associated with changes in self-reported dietary restraint, dietary disinhibition, and susceptibility to hunger measured using the Three-Factor Eating Questionnaire (TFEQ). RESULTS: During the 12-month study, 132 participants completed a mean of 1062 random EMA surveys (range: 673-1362). The median time it took for participants to complete random EMA surveys was 20 s and 90% of random EMA surveys were completed within 46 s. The number of completed random EMA surveys was not significantly associated with the TFEQ scores. CONCLUSIONS: Intensive longitudinal EMA did not influence self-reported eating behaviors. The findings suggest that EMA can be used to frequently assess real-world eating behaviors with minimal concern about assessment reactivity. Nonetheless, care must be taken when designing EMA surveys-particularly when using self-reported outcome measures. LEVEL OF EVIDENCE: Level III, prospective observational study.

Nightly Variation in Sleep Influences Self-efficacy for Adhering to a Healthy Lifestyle: A Prospective Study.

BACKGROUND: Self-efficacy, or the perceived capability to engage in a behavior, has been shown to play an important role in adhering to weight loss treatment. Given that adherence is extremely important for successful weight loss outcomes and that sleep and self-efficacy are modifiable factors in this relationship, we examined the association between sleep and self-efficacy for adhering to the daily plan. Investigators examined whether various dimensions of sleep were associated with self-efficacy for adhering to the daily recommended lifestyle plan among participants (N = 150) in a 12-month weight loss study. METHOD: This study was a secondary analysis of data from a 12-month prospective observational study that included a standard behavioral weight loss intervention. Daily assessments at the beginning of day (BOD) of self-efficacy and the previous night's sleep were collected in real-time using ecological momentary assessment. RESULTS: The analysis included 44,613 BOD assessments. On average, participants reported sleeping for 6.93 ± 1.28 h, reported 1.56 ± 3.54 awakenings, and gave low ratings for trouble sleeping (3.11 ± 2.58; 0: no trouble; 10: a lot of trouble) and mid-high ratings for sleep quality (6.45 ± 2.09; 0: poor; 10: excellent). Participants woke up feeling tired 41.7% of the time. Using linear mixed effects modeling, a better rating in each sleep dimension was associated with higher self-efficacy the following day (all p values < .001). CONCLUSION: Our findings supported the hypothesis that better sleep would be associated with higher levels of reported self-efficacy for adhering to the healthy lifestyle plan.

The association between sleep health and weight change during a 12-month behavioral weight loss intervention.

BACKGROUND: Prior research on the relationship between sleep and attempted weight loss failed to recognize the multidimensional nature of sleep. We examined the relationship between a composite measure of sleep health and change in weight and body composition among adults in a weight loss intervention. METHODS: Adults (N = 125) with overweight or obesity (50.3 ± 10.6 years, 91% female, 81% white) participated in a 12-month behavioral weight loss intervention, with assessments of sleep, weight, fat mass, and fat-free mass at baseline, 6 months, and 12 months. Six sleep dimensions (regularity, satisfaction, alertness, timing, efficiency, and duration) were categorized as "good" or "poor" using questionnaires and actigraphy. A composite score was calculated by summing the number of "good" dimensions. Obstructive sleep apnea (OSA) was assessed in a subsample (n = 117), using the apnea-hypopnea index (AHI) to determine OSA severity. Linear mixed modeling was used to examine the relationships between sleep health and outcomes of percent weight, fat mass, or fat-free mass change during the subsequent 6-month interval, adjusting for age, sex, bed partner, and race; an additional model adjusted for AHI. RESULTS: Mean baseline and 6-month sleep health was 4.5 ± 1.1 and 4.5 ± 1.2, respectively. Mean weight, fat mass, and fat-free mass changes from 0 to 6 months were -9.3 ± 6.1%, -16.9 ± 13.5%, and -3.4 ± 3.4%, respectively, and 0.4 ± 4.8%, -0.3 ± 10.3%, and 0.7 ± 4.1% from 6 to 12 months. Better sleep health was associated with greater subsequent weight loss (P = 0.016) and fat loss (P = 0.006), but not fat-free mass loss (P = 0.232). Following AHI adjustment, the association between sleep health and weight loss was attenuated (P = 0.102) but remained significant with fat loss (P = 0.040). Regularity, satisfaction, timing, and efficiency were each associated with weight and/or fat loss (P ≤ 0.041). CONCLUSIONS: Better sleep health was associated with greater weight and fat loss, with associations attenuated after accounting for OSA severity. Future studies should explore whether improving sleep health, OSA, or the combination improves weight loss.

Ecological momentary assessment of stress, racism and other forms of discrimination during pregnancy using smartphone technology.

BACKGROUND: In the United States, there are considerable racial inequities in adverse perinatal outcomes. Exposure to racism, sexism, and other forms of oppression may help explain these inequities. OBJECTIVES: To describe the application of real-time data collection using ecological momentary assessment (EMA) and smartphone technology to assess exposure to stress, racism, sexism, microaggressions, and other forms of oppression. METHODS: The Postpartum Mothers Mobile Study (PMOMS) is an ongoing longitudinal cohort study that began recruitment in December 2017. Participants delivering at a hospital in Pittsburgh, PA are recruited by 29 weeks' gestation. Using smartphones and smart scales, participants complete daily surveys related to psychosocial, behavioural, and contextual factors and weigh themselves weekly for approximately 15 months. We provide a preliminary descriptive analysis of EMA self-reported measures of stress, racism, sexism, and microaggressions; and non-EMA measures of stress and major discrimination. RESULTS: The sample (n = 230) is 63.5% White, 24.8% Black/African American, and 7% Hispanic origin. The most commonly reported item from the Major Discrimination Scale is being unfairly fired (18.1% of the sample). Of those, 31.7% and 17.1% attribute unfair firing to their gender and race, respectively. From the random EMA measures, on average, participants report experiences of racism and sexism at least once daily, in an average 12-hour day over the 4-week period. Black participants indicate about two experiences per day of racism, and White participants indicate more than 1 per day of sexism. Mean stress levels from the EMA measures were similar to the stress measures collected at baseline. CONCLUSIONS: The methods applied in PMOMS provide real-time data regarding how participants' daily experiences of stress and discrimination influence their lives. Future work will include understanding if and how these EMA measures may relate to already established measures of racism, sexism, and stress; and ultimately understanding associations with perinatal inequities.

Law Accommodating Nonmotorized Road Users and Pedestrian Fatalities in Florida, 1975 to 2013.

OBJECTIVES: To examine the effect of Florida's adoption of Statute 335.065-a law requiring the routine accommodation of nonmotorized road users (i.e., a "Complete Streets" policy)-on pedestrian fatalities and to identify factors influencing its implementation. METHODS: We used a multimethod design (interrupted time-series quasi-experiment and interviews) to calculate Florida's pedestrian fatality rates from 1975 to 2013-39 quarters before and 117 quarters after adoption of the law. Using statistical models, we compared Florida with regional and national comparison groups. Semistructured interviews were conducted with 10 current and former Florida transportation professionals in 2015. RESULTS: Florida's pedestrian fatality rates decreased significantly-by at least 0.500% more each quarter-after Statute 335.065 was adopted, resulting in more than 3500 lives saved across 29 years. Interviewees described supports and challenges associated with implementing the law. CONCLUSIONS: Florida Statute 335.065 is associated with a 3-decade decrease in pedestrian fatalities. The study also reveals factors that influenced the implementation and effectiveness of the law. Public Health Implications. Transportation policies-particularly Complete Streets policies-can have significant, quantifiable impacts on population health. Multimethod designs are valuable approaches to policy evaluations.

Elevated Nicotine Dependence Scores among Electronic Cigarette Users at an Electronic Cigarette Convention.

Electronic cigarette (e-cigarette) conventions are trade shows held across the globe to promote e-cigarette products and provide a venue for users to socialize. E-cigarette users that attend these events likely represent the most intensive e-cigarette user group. No study has characterized addiction and behavior characteristics in this population. We surveyed 131 e-cigarette users attending a large Southeastern e-cigarette convention in Fall 2015. All questions from the Fagerstrom Test for Nicotine Dependence (FTND), select questions from the Penn State Electronic Cigarette Dependence Index, and novel user behavior questions were included. In total, 25 questions were included in the survey. FTND scores were calculated for each respondent who answered all six FTND questions (n = 117). Fisher's Exact Chi square test was used to assess the relationship between addiction and behavior characteristics and FTND scores. Most respondents were classified as moderately dependent (score 5-7, 45.3% of respondents). Length of use, waking at night to use an e-cigarette, strength of cravings, strength of urges over the past week, and frequency of visiting e-cigarette blogs were significantly associated with FTND scores. E-cigarettes users have average FTND scores higher than tobacco smokers. Scores were not significantly associated with prior tobacco cigarette use. Characteristics associated with tobacco smokers' nicotine addiction, such as waking at night to smoke and strength of cravings experienced, are relevant to e-cigarette users. E-cigarettes do not contain the magnitude of toxicants in tobacco cigarettes, but e-cigarettes may produce new chemical exposures evidenced by the adverse health effects reported by some respondents.

Ecological Momentary Assessment in Behavioral Research: Addressing Technological and Human Participant Challenges.

BACKGROUND: Ecological momentary assessment (EMA) assesses individuals' current experiences, behaviors, and moods as they occur in real time and in their natural environment. EMA studies, particularly those of longer duration, are complex and require an infrastructure to support the data flow and monitoring of EMA completion. OBJECTIVE: Our objective is to provide a practical guide to developing and implementing an EMA study, with a focus on the methods and logistics of conducting such a study. METHODS: The EMPOWER study was a 12-month study that used EMA to examine the triggers of lapses and relapse following intentional weight loss. We report on several studies that informed the implementation of the EMPOWER study: (1) a series of pilot studies, (2) the EMPOWER study's infrastructure, (3) training of study participants in use of smartphones and the EMA protocol and, (4) strategies used to enhance adherence to completing EMA surveys. RESULTS: The study enrolled 151 adults and had 87.4% (132/151) retention rate at 12 months. Our learning experiences in the development of the infrastructure to support EMA assessments for the 12-month study spanned several topic areas. Included were the optimal frequency of EMA prompts to maximize data collection without overburdening participants; the timing and scheduling of EMA prompts; technological lessons to support a longitudinal study, such as proper communication between the Android smartphone, the Web server, and the database server; and use of a phone that provided access to the system's functionality for EMA data collection to avoid loss of data and minimize the impact of loss of network connectivity. These were especially important in a 1-year study with participants who might travel. It also protected the data collection from any server-side failure. Regular monitoring of participants' response to EMA prompts was critical, so we built in incentives to enhance completion of EMA surveys. During the first 6 months of the 12-month study interval, adherence to completing EMA surveys was high, with 88.3% (66,978/75,888) completion of random assessments and around 90% (23,411/25,929 and 23,343/26,010) completion of time-contingent assessments, despite the duration of EMA data collection and challenges with implementation. CONCLUSIONS: This work informed us of the necessary preliminary steps to plan and prepare a longitudinal study using smartphone technology and the critical elements to ensure participant engagement in the potentially burdensome protocol, which spanned 12 months. While this was a technology-supported and -programmed study, it required close oversight to ensure all elements were functioning correctly, particularly once human participants became involved.

Mixed effects models for recurrent events data with partially observed time-varying covariates: Ecological momentary assessment of smoking.

Cigarette smoking is a prototypical example of a recurrent event. The pattern of recurrent smoking events may depend on time-varying covariates including mood and environmental variables. Fixed effects and frailty models for recurrent events data assume that smokers have a common association with time-varying covariates. We develop a mixed effects version of a recurrent events model that may be used to describe variation among smokers in how they respond to those covariates, potentially leading to the development of individual-based smoking cessation therapies. Our method extends the modified EM algorithm of Steele (1996) for generalized mixed models to recurrent events data with partially observed time-varying covariates. It is offered as an alternative to the method of Rizopoulos, Verbeke, and Lesaffre (2009) who extended Steele's (1996) algorithm to a joint-model for the recurrent events data and time-varying covariates. Our approach does not require a model for the time-varying covariates, but instead assumes that the time-varying covariates are sampled according to a Poisson point process with known intensity. Our methods are well suited to data collected using Ecological Momentary Assessment (EMA), a method of data collection widely used in the behavioral sciences to collect data on emotional state and recurrent events in the every-day environments of study subjects using electronic devices such as Personal Digital Assistants (PDA) or smart phones.

Changes in the concentrations of biochemical indicators of diet and nutritional status of pregnant women across pregnancy trimesters in Trujillo, Peru, 2004-2005.

BACKGROUND: In developing countries, deficiencies in essential micronutrients are common, particularly in pregnant women. Although, biochemical indicators of diet and nutrition are useful to assess nutritional status, few studies have examined such indicators throughout pregnancy in women in developing countries. METHODS: The primary objective of this study was to assess the nutritional status of 78 Peruvian women throughout pregnancy for 16 different nutritional indicators including fat-soluble vitamins and carotenoids, iron-status indicators, and selenium. Venous blood samples from which serum was prepared were collected during trimesters one (n = 78), two (n = 65), three (n = 62), and at term via the umbilical cord (n = 52). Questionnaires were completed to determine the demographic characteristics of subjects. Linear mixed effects models were used to study the associations between each maternal indicator and the demographic characteristics. RESULTS: None of the women were vitamin A and E deficient at any stage of pregnancy and only 1/62 women (1.6%) was selenium deficient during the third trimester. However, 6.4%, 44% and 64% of women had ferritin levels indicative of iron deficiency during the first, second and third trimester, respectively. Statistically significant changes (p ≤ 0.05) throughout pregnancy were noted for 15/16 nutritional indicators for this Peruvian cohort, with little-to-no association with demographic characteristics. Three carotenoids (beta-carotene, beta-cryptoxanthin and trans-lycopene) were significantly associated with education status, while trans-lycopene was associated with age and beta-cryptoxanthin with SES (p < 0.05). Concentrations of retinol, tocopherol, beta-cryptoxanthin, lutein + zeaxanthin and selenium were lower in cord serum compared with maternal serum (p < 0.05). Conversely, levels of iron status indicators (ferritin, transferrin saturation and iron) were higher in cord serum (p < 0.05). CONCLUSION: The increasing prevalence of iron deficiency throughout pregnancy in these Peruvian women was expected. It was surprising though not to find deficiencies in other nutrients. The results highlight the importance of continual monitoring of women throughout pregnancy for iron deficiency which could be caused by increasing fetal needs and/or inadequate iron intake as pregnancy progresses.

Using exhaled carbon monoxide and carboxyhemoglobin to evaluate the effectiveness of a chimney stove model in Peru.

BACKGROUND: Measurement of biological indicators of physiological change may be useful in evaluating the effectiveness of stove models, which are intended to reduce indoor smoke exposure and potential health effects. OBJECTIVES: We examined changes in exhaled carbon monoxide (CO), percentage carboxy-hemoglobin, and total hemoglobin in response to the installation of a chimney stove model by the Juntos National Program in Huayatan, Peru in 2008. METHODS: Biomarkers were measured in a convenience sample comprising 35 women who met requirements for participation, and were measured before and three weeks after installation of a chimney stove. The relationships between exposure to indoor smoke and biomarker measurements were also analyzed using simple linear regression models. RESULTS: Exhaled CO reduced from 6.71 ppm (95% CI 5.84-7.71) to 3.14 ppm (95% CI 2.77-3.66) three weeks after stove installation (P < 0.001) while % COHb reduced from 1.76% (95% CI 1.62-1.91) to 1.18% (95% CI 1.12-1.25; P < 0.001). Changes in exhaled CO and % COHb from pre- to post-chimney stove installation were not correlated with corresponding changes in exposure to CO and PM2.5 even though the exposures also reduced after stove installation. CONCLUSION: Exhaled CO and % COHb both showed improvement with reduction in concentration after the installation of the chimney cook stoves, indicating a positive physiological response subsequent to the intervention.

Radionuclide activity concentrations in forest surface fuels at the Savannah River Site.

BACKGROUND/OBJECTIVE: A study was undertaken at the United States Department of Energy's Savannah River Site (SRS), Aiken, South Carolina to investigate radionuclide activity concentrations in litter and duff from select areas at SRS. Litter (i.e. vegetative debris) and duff (i.e. highly decomposed vegetative debris) can often be the major fuels consumed during prescribed burns and have potential to release radiological contaminants into the environment. METHODS: Repeated samples from 97 locations were collected systematically across SRS and analyzed for radionuclide activity. Radionuclide activity concentrations found in litter and duff were compared. As spatial trends were of interest, spatial distributions of radionuclide activity concentrations found in litter and duff and spatial dependency amongst the data were explored. RESULTS: (7)Be, (40)K, and (137)Cs showed statistically significant proportional differences between litter and duff samples. Duff sample concentrations for (137)Cs (p < 0.0001) and (40)K (p = 0.0015) were statistically higher compared to litter samples. (7)Be activity concentrations were statistically higher in litter as compared to duff (p < 0.0001). For (40)K litter and duff samples, spatial correlation tests were not significant at p = 0.05 and the maps did not indicate any apparent high concentrations centered near possible radionuclide sources (i.e. SRS facilities). For (7)Be litter samples, significant spatial correlation was calculated (p = 0.0085). No spatial correlation was evident in the (7)Be duff samples (p = 1.0000) probably due to small sample size (n = 7). (137)Cs litter and duff samples showed significant spatial correlations (p < 0.0001 and p < 0.0001, respectively). CONCLUSIONS: To date, few studies characterize radionuclide activity concentrations in litter and duff, and to our knowledge none present spatial analysis. Key findings show that across SRS, (137)Cs is the primary radionuclide of concern, with the highest number of samples reported above MDC in litter (51.4%) and duff samples (83.2%). However, (137)Cs litter and duff spatial trends in the maps generated from the kriging parameters do not appear to directly link the areas with higher activity concentrations with SRS facilities. The results found herein provide valuable baseline monitoring data for future studies of forest surface fuels and can be used to evaluate changes in radioactivity in surface fuels in the southeast region of the U.S.

Inflammatory effects of woodsmoke exposure among wildland firefighters working at prescribed burns at the Savannah River Site, SC.

Wildland firefighters in the United States are occupationally exposed to high levels of woodsmoke. Results from experimental studies show that exposure to woodsmoke induces inflammation. A study was conducted to investigate the effect of occupational woodsmoke exposure on inflammatory biomarkers in firefighters working at prescribed burns. Twelve U.S. Forest Service wildland firefighters at the Savannah River Site, South Carolina, volunteered to give blood samples during four prescribed burns between February and March 2011. Twenty-four paired (pre- and post-work shift) blood samples were collected using dried blood spot method to facilitate repeated sample collection. Inflammatory biomarker concentrations in blood samples were measured using the Meso Scale Discovery multi-spot assay system. Concurrent personal PM2.5 and CO monitoring of firefighters was conducted. Linear mixed models were used to test whether cross-work shift differences occurred in the following inflammatory biomarkers: IL-1ß, IL-8, CRP, SAA, ICAM-1, and VCAM-1. IL-8 showed a significant cross-work shift difference as indicated by a post/pre-work shift ratio of 1.70 (95% CL: 1.35, 2.13; p = 0.0012). Concentrations of IL-8, CRP, and ICAM-1 increased in >50% of samples across work shift. Firefighters who lighted fires as opposed to other work tasks had the largest cross-work shift increase in IL-8. A significant cross-work shift increase in IL-8 in blood samples was observed in healthy wildland firefighters working at prescribed burns. Further research is needed to understand the physiological responses underlying the adverse effects of woodsmoke exposure, and the dose-response relationship between woodsmoke exposure and inflammatory responses.

Agreement between Fitbit and ActiGraph Estimates of Physical Activity in Young Children.

Physical activity (PA) estimates from the Fitbit Flex 2 were compared to those from the ActiGraph GT9X Link in 123 elementary school children. Steps and intensity-specific estimates of PA and 3-month PA change were calculated using two different ActiGraph cut-points (Evenson and Romanzini). Fitbit estimates were 35% higher for steps compared to the ActiGraph. Fitbit and ActiGraph intensity-specific estimates were closest for sedentary and light PA while estimates of moderate and vigorous PA varied substantially depending upon the ActiGraph cut-points used. Spearman correlations between device estimates were higher for steps (rs=.70) than for moderate (rs =.54 to .55) or vigorous (rs =.29 to .48) PA. There was low concordance between devices in assessing PA changes over time. Agreement between Fitbit Flex 2 and ActiGraph estimates may depend upon the cut-points used to classify PA intensity. However, there is fair to good agreement between devices in ranking children's steps and MVPA.

Direct wastewater extraction as a simple and effective method for SARS-CoV-2 surveillance and COVID-19 community-level monitoring.

Wastewater surveillance has proven to be an effective tool to monitor the transmission and emergence of infectious agents at a community scale. Workflows for wastewater surveillance generally rely on concentration steps to increase the probability of detection of low-abundance targets, but preconcentration can substantially increase the time and cost of analyses while also introducing additional loss of target during processing. To address some of these issues, we conducted a longitudinal study implementing a simplified workflow for SARS-CoV-2 detection from wastewater, using a direct column-based extraction approach. Composite influent wastewater samples were collected weekly for 1 year between June 2020 and June 2021 in Athens-Clarke County, Georgia, USA. Bypassing any concentration step, low volumes (280 µl) of influent wastewater were extracted using a commercial kit, and immediately analyzed by RT-qPCR for the SARS-CoV-2 N1 and N2 gene targets. SARS-CoV-2 viral RNA was detected in 76% (193/254) of influent samples, and the recovery of the surrogate bovine coronavirus was 42% (IQR: 28%, 59%). N1 and N2 assay positivity, viral concentration, and flow-adjusted daily viral load correlated significantly with per-capita case reports of COVID-19 at the county-level (ρ = 0.69-0.82). To compensate for the method's high limit of detection (approximately 106-107 copies l-1 in wastewater), we extracted multiple small-volume replicates of each wastewater sample. With this approach, we detected as few as five cases of COVID-19 per 100 000 individuals. These results indicate that a direct-extraction-based workflow for SARS-CoV-2 wastewater surveillance can provide informative and actionable results.

Examining demographic and psychosocial factors related to self-weighing behavior during pregnancy and postpartum periods.

Black childbearing individuals in the US experience a higher risk of postpartum weight retention (PPWR) compared to their White counterparts. Given that PPWR is related to adverse health outcomes, it is important to investigate predictors of weight-related health behaviors, such as self-weighing (i.e., using a scale at home). Regular self-weighing is an evidence-based weight management strategy, but there is minimal insight into sociodemographic factors related to frequency. The Postpartum Mothers Mobile Study (PMOMS) facilitated longitudinal ambulatory weight assessments to investigate racial inequities in PPWR. Our objective for the present study was to describe self-weighing behavior during and after pregnancy in the PMOMS cohort, as well as related demographic and psychosocial factors. Applying tree modeling and multiple regression, we examined self-weighing during and after pregnancy. Participants (N = 236) were 30.2 years old on average (SD = 4.7), with the majority being college-educated (53.8%, n = 127), earning at least $30,000 annually (61.4%, n = 145), and self-identifying as non-Hispanic White (NHW; 68.2%, n = 161). Adherence to regular self-weighing (at least once weekly) was highest among participants during pregnancy, with a considerable decline after giving birth. Low-income Black participants (earning < $30,000) were significantly less likely to reach a completion rate of ≥ 80% during pregnancy (AOR = 0.10) or the postpartum period (AOR = 0.16), compared to NHW participants earning at least $30,000 annually. Increases in perceived stress were associated with decreased odds of sustained self-weighing after delivery (AOR = 0.79). Future research should consider behavioral differences across demographic intersections, such as race and socioeconomic status, and the impact on efficacy of self-weighing.

Mean corrected generalized estimating equations for longitudinal binary outcomes with report bias.

Cocaine addiction is an important public health problem worldwide. Cognitive-behavioral therapy is a counseling intervention for supporting cocaine-dependent individuals through recovery and relapse prevention. It may reduce patients' cocaine uses by improving their motivations and enabling them to recognize risky situations. To study the effect of cognitive behavioral therapy on cocaine dependence, the self-reported cocaine use with urine test data were collected at the Primary Care Center of Yale-New Haven Hospital. Its outcomes are binary, including both the daily self-reported drug uses and weekly urine test results. To date, the generalized estimating equations are widely used to analyze binary data with repeated measures. However, due to the existence of significant self-report bias in the self-reported cocaine use with urine test data, a direct application of the generalized estimating equations approach may not be valid. In this paper, we proposed a novel mean corrected generalized estimating equations approach for analyzing longitudinal binary outcomes subject to reporting bias. The mean corrected generalized estimating equations can provide consistently and asymptotically normally distributed estimators under true contamination probabilities. In the self-reported cocaine use with urine test study, accurate weekly urine test results are used to detect contamination. The superior performances of the proposed method are illustrated by both simulation studies and real data analysis.

Differences in Fine Particle Exposure and Estimated Pulmonary Ventilation Rate with Respect to Work Tasks of Wildland Firefighters at Prescribed Burns: A Repeated Measures Study.

Wildland firefighters (WLFFs) are exposed to a mixture of chemicals found in wildland fire smoke and emissions from nonwildland-fuel smoke sources such as diesel. We investigated compositional differences in exposure to particulate matter and explored differences in ventilation rate and potential inhaled dose relative to the work tasks of WLFFs. Repeated measures on ten professional and two volunteer firefighters were collected on prescribed burn and nonburn days. Personal monitoring consisted of real-time and gravimetric fine particulate matter (PM2.5), carbon monoxide (CO), and accelerometer measurements to estimate ventilation rate and potential dose of PM2.5. The fine particulate matter was analyzed for levoglucosan (LG) and light absorbing carbon as a surrogate for black carbon (BC). Breathing zone personal exposure concentrations of PM2.5, LG, BC, and CO were higher on burn days (P < 0.05). Differences in exposure concentrations were observed between burn day tasks (P < 0.05) with firefighters managing fire boundaries (holders) being exposed to higher CO and LG concentrations and less BC concentrations than those conducting lighting (lighters). While no statistical difference in PM2.5 exposure measures was observed between the two tasks, holders in the study tended to be exposed to higher PM2.5 concentrations (~1.4×), while lighters tended to have more inhaled amounts of PM2.5 (~1.3×). Our findings demonstrate possible diversity in the sources of particulate matter exposure at the fireline and suggest the potential importance of using dose as a metric of inhalation exposure in occupational or other settings.

Spatial Analysis of the 2017 Outbreak of Hemorrhagic Disease and Physiographic Region in the Eastern United States.

Hemorrhagic disease (HD) is considered one of the most significant infectious diseases of white-tailed deer in North America. Investigations into environmental conditions associated with outbreaks suggest drought conditions are strongly correlated with outbreaks in some regions of the United States. However, during 2017, an HD outbreak occurred in the Eastern United States which appeared to be associated with a specific physiographic region, the Appalachian Plateau, and not drought conditions. The objective of this study was to determine if reported HD in white-tailed deer in 2017 was correlated with physiographic region. There were 456 reports of HD from 1605 counties across 26 states and 12 physiographic regions. Of the 93 HD reports confirmed by virus isolation, 76.3% (71/93) were identified as EHDV-2 and 66.2% (47/71) were from the Appalachian Plateau. A report of HD was 4.4 times more likely to occur in the Appalachian Plateau than not in 2017. Autologistic regression models suggested a statistically significant spatial dependence. The underlying factors explaining this correlation are unknown, but may be related to a variety of host, vector, or environmental factors. This unique outbreak and its implications for HD epidemiology highlight the importance for increased surveillance and reporting efforts in the future.

Clinical management of an outbreak of nutritionally variant streptococcus endophthalmitis following intravitreal bevacizumab injection.

BACKGROUND: The management of an outbreak of endophthalmitis associated with intravitreal bevacizumab represents a challenging real-time process involving identification of cases, treatment and mitigation measures during the outbreak. We summarize the clinical presentation and management of a cluster of endophthalmitis cases from contaminated bevacizumab, in addition to mathematical probabilistic assessment of the number of cases that define an outbreak. METHODS: A retrospective study was conducted to assess the management of an endophthalmitis outbreak after intravitreal bevacizumab (IVB) administration. Demographic data, clinical information, individual patient management and public health reporting measures were reviewed. Outcomes of patients who received prophylactic antibiotics for endophthalmitis prevention were also reviewed. Binomial tail probability calculations were performed to determine the likelihood of clusters of endophthalmitis that could inform when an outbreak was evolving that would warrant more public health notification measures and communication. RESULTS: Forty-five eyes of 42 patients who received IVB from a single batch were reviewed. Four cases of endophthalmitis from Granulicatella adiacens, a nutritionally-variant Streptococcus species, were treated successfully with intravitreal antibiotics ± vitrectomy. Thirty-four of the remaining 41 eyes were treated with prophylactic intravitreal vancomycin with no additional cases of endophthalmitis. Outbreak management also included CDC, ASRS and public health authority notification. Binominal tail probabilities demonstrated the rarity of clusters from a single batch (i.e. ~ 1/10,000 for 2 cases; 1/2 million for 3 cases). However, given the U.S. scale of IVB administration, there is an 87% chance of a cluster ≧ 2 and a 1% chance of a cluster ≧ 3 cases annually, which may guide outbreak management. A process diagram was developed to incorporate patient management and public health measures when an outbreak is suspected. CONCLUSION: Intravitreal antibiotics and vitrectomy were effective in the individual management of cases of endophthalmitis, and no serious adverse events occurred with prophylactic intravitreal vancomycin for at-risk eyes. Best practices for outbreaks should be evaluated, given their likelihood within the U.S. and the sight-threatening consequences of endophthalmitis.

Effectiveness of neuraminidase inhibitors to prevent mortality in patients with laboratory-confirmed avian influenza A H7N9.

OBJECTIVES: Avian influenza virus A(H7N9) remains a threat to humans and has great potential to cause a pandemic in the foreseeable future. Antiviral treatment with neuraminidase inhibitors has been recommended to treat patients with H7N9 infection as early as possible, although evidence-based research on their effectiveness for H7N9 infection is lacking. METHODS: Data from all laboratory-confirmed cases of H7N9 infection in Zhejiang Province between 2013 and 2017 were retrieved, and time-dependent survival models were used to evaluate the effectiveness of treatment with neuraminidase inhibitors to reduce the risk of mortality. RESULTS: The final optimal model found no significant association (odds ratio 1.29, 95% confidence interval 0.78-2.15) between time to treatment with neuraminidase inhibitors and survival after controlling for age and white blood cell count. Sensitivity analyses with multiple imputation for missing data concurred with the primary analysis. CONCLUSIONS: No association was found between treatment with neuraminidase inhibitors and survival in patients with H7N9 infection using various adjusted models and sensitivity analyses of missing data imputations.