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Dive into the research topics where Claudia C. Ma is active.

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Featured researches published by Claudia C. Ma.


Journal of Occupational and Environmental Medicine | 2014

Prevalence of obesity by occupation among US workers: the National Health Interview Survey 2004-2011.

Ja K. Gu; Luenda E. Charles; Ki Moon Bang; Claudia C. Ma; Michael E. Andrew; John M. Violanti; Cecil M. Burchfiel

Objective: To estimate the prevalence of obesity and the change of prevalence of obesity between 2004−2007 and 2008−20011 by occupation among US workers in the National Health Interview Survey. Methods: Self-reported weight and height were collected and used to assess obesity (body mass index ≥ 30 kg/m2). Gender-, race/ethnicity-, and occupation-specific prevalence of obesity were calculated. Results: Prevalence of obesity steadily increased from 2004 through 2008 across gender and race/ethnicity but leveled off from 2008 through 2011. Non-Hispanic black female workers in health care support (49.2%) and transportation/material moving (46.6%) had the highest prevalence of obesity. Prevalence of obesity in relatively low-obesity (white-collar) occupations significantly increased between 2004−2007 and 2008−2011, whereas it did not change significantly in high-obesity (blue-collar) occupations. Conclusions: Workers in all occupational categories are appropriate targets for health promotion and intervention programs to reduce obesity.


Journal of Occupational and Environmental Medicine | 2012

Long Work Hours and Adiposity Among Police Officers in a US Northeast City

Ja K. Gu; Luenda E. Charles; Cecil M. Burchfiel; Desta Fekedulegn; Khachatur Sarkisian; Michael E. Andrew; Claudia C. Ma; John M. Violanti

Objective: To investigate the associations between long work hours and adiposity measures in police officers. Methods: Participants included 408 officers from the Buffalo Cardio-Metabolic Occupational Police Stress study who were examined between 2004 and 2009. Total work hours were abstracted from payroll records and questionnaires. Analysis of variance and covariance models were used. Results: Among male officers who worked the midnight shift, mean values of waist circumference and body mass index increased with longer work hours after adjustment for age, physical activity, energy intake, sleep duration, smoking status, police rank, activities after work (eg, child/family care, sports), and household income. Adiposity measures were not associated with work hours among women on any shift. Conclusion: Working longer hours was significantly associated with larger waist circumferences and higher body mass index among male police officers working the midnight shift.


Safety and health at work | 2015

Shift Work and Occupational Stress in Police Officers

Claudia C. Ma; Michael E. Andrew; Desta Fekedulegn; Ja K. Gu; Tara A. Hartley; Luenda E. Charles; John M. Violanti; Cecil M. Burchfiel

Background Shift work has been associated with occupational stress in health providers and in those working in some industrial companies. The association is not well established in the law enforcement workforce. Our objective was to examine the association between shift work and police work-related stress. Methods The number of stressful events that occurred in the previous month and year was obtained using the Spielberger Police Stress Survey among 365 police officers aged 27–66 years. Work hours were derived from daily payroll records. A dominant shift (day, afternoon, or night) was defined for each participant as the shift with the largest percentage of total time a participant worked (starting time from 4:00 AM to 11:59 AM, from 12 PM to 7:59 PM, and from 8:00 PM to 3:59 AM for day, afternoon, and night shift, respectively) in the previous month or year. Analysis of variance and covariance were used to examine the number of total and subscale (administrative/professional pressure, physical/psychological danger, or organizational support) stressful events across the shift. Results During the previous month and year, officers working the afternoon and night shifts reported more stressful events than day shift officers for total stress, administrative/professional pressure, and physical/psychological danger (p < 0.05). These differences were independent of age, sex, race/ethnicity, and police rank. The frequency of these stressful events did not differ significantly between officers working the afternoon and night shifts. Conclusion Non–day shift workers may be exposed to more stressful events in this cohort. Interventions to reduce or manage police stress that are tailored by shift may be considered.


Journal of Occupational and Environmental Medicine | 2011

Association of Shift Work With Physical Activity Among Police Officers The Buffalo Cardio-Metabolic Occupational Police Stress Study

Claudia C. Ma; Cecil M. Burchfiel; Desta Fekedulegn; Michael E. Andrew; Luenda E. Charles; Ja K. Gu; Anna Mnatsakanova; John M. Violanti

Objective: To examine relations of shift work with occupational, sports, and household physical activity (PA) among police officers. Methods: Self-reported PA was assessed among 350 male and female officers (aged 27 to 66). Day, afternoon, or midnight shift was identified from daily payroll records. Results: Shift work was associated with prevalence of hard-intensity (occupational and sport) PA among men, and very hard-intensity sport PA among women, with afternoon workers reporting the highest prevalence. Shift work was independently associated with total hours of hard-intensity PA among men and very hard-intensity PA among women, with afternoon workers reporting the most hours. Conclusion: Results indicated that hard and very hard-intensity PA varied significantly across shifts with afternoon workers being the most active.


American Journal of Industrial Medicine | 2013

Associations of Objectively Measured and Self-Reported Sleep Duration With Carotid Artery Intima Media Thickness Among Police Officers

Claudia C. Ma; Cecil M. Burchfiel; Luenda E. Charles; Joan Dorn; Michael E. Andrew; Ja Kook Gu; Parveen Nedra Joseph; Desta Fekedulegn; James E. Slaven; Tara A. Hartley; Anna Mnatsakanova; John M. Violanti

BACKGROUND We aimed to examine the association of objectively measured and self-reported sleep duration with carotid artery intima media thickness (IMT) among 257 police officers, a group at high risk for cardiovascular disease (CVD). METHODS Sleep duration was estimated using actigraphic data and through self-reports. The mean maximum IMT was the average of the largest 12 values scanned bilaterally from three angles of the near and far wall of the common carotid, bulb, and internal carotid artery. Linear and quadratic regression models were used to assess the association of sleep duration with IMT. RESULTS Officers who had fewer than 5 or 8 hr or more of objectively measured sleep duration had significantly higher maximum IMT values, independent of age. Self-reported sleep duration was not associated with either IMT measure. CONCLUSION Attainment of sufficient sleep duration may be considered as a possible strategy for atherosclerosis prevention among police officers.


Environmental Health Perspectives | 2017

Combined Prenatal Pesticide Exposure and Folic Acid Intake in Relation to Autism Spectrum Disorder

Rebecca J. Schmidt; Vladimir Kogan; Janie F. Shelton; Lora Delwiche; Robin L. Hansen; Sally Ozonoff; Claudia C. Ma; Erin C. McCanlies; Deborah H. Bennett; Irva Hertz-Picciotto; Daniel J. Tancredi; Heather E. Volk

Background: Maternal folic acid (FA) protects against developmental toxicity from certain environmental chemicals. Objective: We examined combined exposures to maternal FA and pesticides in relation to autism spectrum disorder (ASD). Methods: Participants were California children born from 2000–2007 who were enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) case–control study at age 2–5 y, were clinically confirmed to have ASD (n=296) or typical development (n=220), and had information on maternal supplemental FA and pesticide exposures. Maternal supplemental FA and household pesticide product use were retrospectively collected in telephone interviews from 2003–2011. High vs. low daily FA intake was dichotomized at 800μg (median). Mothers’ addresses were linked to a statewide database of commercial applications to estimate agricultural pesticide exposure. Results: High FA intake (≥800μg) during the first pregnancy month and no known pesticide exposure was the reference group for all analyses. Compared with this group, ASD was increased in association with <800μg FA and any indoor pesticide exposure {adjusted odds ratio [OR]=2.5 [95% confidence interval (CI): 1.3, 4.7]} compared with low FA [OR=1.2 (95% CI: 0.7, 2.2)] or indoor pesticides [OR=1.7 (95% CI: 1.1, 2.8)] alone. ORs for the combination of low FA and regular pregnancy exposure (≥6 mo) to pet pesticides or to outdoor sprays and foggers were 3.9 (95% CI: 1.4, 11.5) and 4.1 (95% CI: 1.7, 10.1), respectively. ORs for low maternal FA and agricultural pesticide exposure 3 mo before or after conception were 2.2 (95% CI: 0.7, 6.5) for chlorpyrifos, 2.3 (95% CI: 0.98, 5.3) for organophosphates, 2.1 (95% CI: 0.9, 4.8) for pyrethroids, and 1.5 (95% CI: 0.5, 4.8) for carbamates. Except for carbamates, these ORs were approximately two times greater than those for either exposure alone or for the expected ORs for combined exposures under multiplicative or additive models. Conclusions: In this study population, associations between pesticide exposures and ASD were attenuated among those with high versus low FA intake during the first month of pregnancy. Confirmatory and mechanistic studies are needed. https://doi.org/10.1289/EHP604


Safety and health at work | 2013

Associations between Psychological Distress and Body Mass Index among Law Enforcement Officers: The National Health Interview Survey 2004-2010

Ja K. Gu; Luenda E. Charles; Cecil M. Burchfiel; Michael E. Andrew; Claudia C. Ma; Ki Moon Bang; John M. Violanti

Objectives To investigate the association between psychological distress and obesity among law enforcement officers (LEOs) in the United States. Methods Self-reported data on psychological distress based on six key questions were obtained from LEOs who participated in the National Health Interview Survey (2004-2010). We used Prochaskas cut-point of a Kessler 6 score ≥ 5 for moderate/high mental distress in our analysis. Mean levels of body mass index (BMI) were compared across three levels of psychological distress. Results The average age of LEOs (n = 929) was 39.3 years; 25% were female. Overall, 8.1% of LEOs had moderate or high psychological distress; 37.5% were obese (BMI ≥ 30). Mean BMI increased with increasing psychological distress (no distress, BMI = 27.2 kg/m2; mild distress, 27.6 kg/m2; and moderate/high distress, 33.1 kg/m2; p = 0.016) after adjustment for age, race, income, and education level among female officers only. Physical activity modified the association between psychological distress and BMI but only among male LEOs (interaction p = 0.002). Among male LEOs reporting low physical activity, psychological distress was positively associated with BMI (30.3 kg/m2 for no distress, 30.7 for mild distress, 31.8 for moderate/high distress; p = 0.179) after adjustment, but not significantly. This association was not significant among males reporting high physical activity. Conclusion Mean BMI significantly increased as psychological distress increased among female LEOs. A longitudinal study design may reveal the directionality of this association as well as the potential role that physical activity might play in this association.


Safety and health at work | 2016

Separate and Joint Associations of Shift Work and Sleep Quality with Lipids

Luenda E. Charles; Ja K. Gu; Cathy Tinney-Zara; Desta Fekedulegn; Claudia C. Ma; Penelope Baughman; Tara A. Hartley; Michael E. Andrew; John M. Violanti; Cecil M. Burchfiel

Background Shift work and/or sleep quality may affect health. We investigated whether shift work and sleep quality, separately and jointly, were associated with abnormal levels of triglycerides, total cholesterol (TC), and low-and high-density lipoprotein cholesterol in 360 police officers (27.5% women). Methods Triglycerides, TC, and high-density lipoprotein were analyzed on the Abbott Architect; low-density lipoprotein was calculated. Shift work was assessed using City of Buffalo payroll work history records. Sleep quality (good, ≤ 5; intermediate, 6–8; poor, ≥ 9) was assessed using the Pittsburgh Sleep Quality Index questionnaire. A shift work + sleep quality variable was created: day plus good sleep; day plus poor sleep; afternoon/night plus good; and poor sleep quality. Mean values of lipid biomarkers were compared across categories of the exposures using analysis of variance/analysis of covariance. Results Shift work was not significantly associated with lipids. However, as sleep quality worsened, mean levels of triglycerides and TC gradually increased but only among female officers (age- and race-adjusted p = 0.013 and 0.030, respectively). Age significantly modified the association between sleep quality and TC. Among officers ≥ 40 years old, those reporting poor sleep quality had a significantly higher mean level of TC (202.9 ± 3.7 mg/dL) compared with those reporting good sleep quality (190.6 ± 4.0 mg/dL) (gender- and race-adjusted p = 0.010). Female officers who worked the day shift and also reported good sleep quality had the lowest mean level of TC compared with women in the other three categories (p = 0.014). Conclusion Sleep quality and its combined influence with shift work may play a role in the alteration of some lipid measures.


Policing-an International Journal of Police Strategies & Management | 2017

Police stressors and health: a state-of-the-art review

John M. Violanti; Luenda E. Charles; Erin C. McCanlies; Tara A. Hartley; Penelope Baughman; Michael E. Andrew; Desta Fekedulegn; Claudia C. Ma; Anna Mnatsakanova; Cecil M. Burchfiel

Purpose – The purpose of this paper is to provide a state-of-the-art review on the topic of police stressors and associated health outcomes. Recent empirical research is reviewed in the areas of workplace stress, shift work, traumatic stress, and health. The authors provide a comprehensive table outlining occupational exposures and related health effects in police officers. Design/methodology/approach – A review of recent empirical research on police stress and untoward psychological and physiological health outcomes in police officers. Findings – The results offer a conceptual idea of the empirical associations between stressful workplace exposures and their impact on the mental and physical well-being of officers. Research limitations/implications – A key limitation observed in prior research is the cross-sectional study design; however, this serves as a motivator for researchers to explore these associations utilizing a longitudinal study design that will help determine causality. Originality/value – This review provides empirical evidence of both mental and physical outcomes associated with police stress and the processes involved in both. Research findings presented in this paper are based on sound psychological and medical evidence among police officers.


Journal of Safety Research | 2016

Prevalence of work-site injuries and relationship between obesity and injury among U.S. workers: NHIS 2004-2012.

Ja K. Gu; Luenda E. Charles; Michael E. Andrew; Claudia C. Ma; Tara A. Hartley; John M. Violanti; Cecil M. Burchfiel

INTRODUCTION Studies have reported associations between obesity and injury in a single occupation or industry. Our study estimated the prevalence of work-site injuries and investigated the association between obesity and work-site injury in a nationally representative sample of U.S. workers. METHODS Self-reported weight, height, and injuries within the previous three months were collected annually for U.S. workers in the National Health Interview Survey (NHIS) from 2004-2012. Participants were categorized as normal weight (BMI: 18.5-24.9kg/m(2)), overweight (BMI: 25.0-29.9), obese I (BMI: 30.0-34.9), and obese II (BMI: 35+). The prevalence of injury and prevalence ratios from fitted logistic regression models was used to assess relationships between obesity and injury after adjusting for covariates. Sampling weights were incorporated using SUDAAN software. RESULTS During the 9-year study period from 2004 to 2012, 1120 workers (78 workers per 10,000) experienced a work-related injury during the previous three months. The anatomical sites with the highest prevalence of injury were the back (14.3/10,000±1.2), fingers (11.5±1.3), and knees (7.1±0.8). The most common types of injuries were sprains/strains/twists (41.5% of all injuries), cuts (20.0%), and fractures (11.8%). Compared to normal weight workers, overweight and obese workers were more likely to experience work-site injuries [overweight: PR=1.25 (95% CI=1.04-1.52); obese I: 1.41 (1.14-1.74); obese II: 1.68 (1.32-2.14)]. These injuries were more likely to affect the lower extremities [overweight: PR=1.48, (95% CI=1.03-2.13); obese I: 1.70 (1.13-2.55); obese II: 2.91 (1.91-4.41)] and were more likely to be due to sprains/strains/twists [overweight: PR=1.73 (95% CI=1.29-2.31); obese I: PR=2.24 (1.64-3.06); obese II: PR=2.95 (2.04-4.26)]. CONCLUSIONS Among NHIS participants, overweight and obese workers were 25% to 68% more likely to experience injuries than normal weight workers. PRACTICAL APPLICATIONS Weight reduction policies and management programs may be effectively targeted towards overweight and obese groups to prevent or reduce work-site injuries.

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Michael E. Andrew

National Institute for Occupational Safety and Health

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Luenda E. Charles

National Institute for Occupational Safety and Health

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Cecil M. Burchfiel

National Institute for Occupational Safety and Health

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Desta Fekedulegn

National Institute for Occupational Safety and Health

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Ja K. Gu

National Institute for Occupational Safety and Health

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Tara A. Hartley

National Institute for Occupational Safety and Health

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Anna Mnatsakanova

National Institute for Occupational Safety and Health

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Ja Kook Gu

National Institute for Occupational Safety and Health

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