Claudia Ma - Academia.edu (original) (raw)

Papers by Claudia Ma

Research paper thumbnail of Association of perceived stress with sleep duration and sleep quality in police officers

International journal of emergency mental health

The objective was to investigate associations ofperceived stress with sleep duration and quality ... more The objective was to investigate associations ofperceived stress with sleep duration and quality among 430 police officers. Perceived stress was assessed using the perceived stress scale. Sleep duration and quality were assessed using the Pittsburg sleep quality index questionnaire. Mean hours of sleep were determined across quartiles of perceived stress using ANOVA/ANCOVA. Logistic regression was used to obtain odds ratios and 95% confidence intervals for poor sleep quality across perceived stress quartiles. Mean age was 42.1 years. Perceived stress was inversely associated with sleep duration among certain groups: men (p = 0.004), higher-ranked officers (p = 0.002), those with higher depressive symptoms (p 0.097), no military experience (p = 0.006), and higher workload (p = 0.003). Gender, police rank, depressive symptoms, and workload each significantly modified the association between stress and sleep duration. Prevalence of poor sleep quality increased with higher levels of per...

Research paper thumbnail of Association of sleep quality with depression in police officers

International journal of emergency mental health, 2011

Poor sleep quality has been shown to adversely affect neurobehavior including an increase in depr... more Poor sleep quality has been shown to adversely affect neurobehavior including an increase in depression symptoms. Police officers are at increased risk of poor sleep quality due to occupational factors. This study analyzed self-reported sleep and depression data from police officers; 391 police officers from Buffalo, New York reported on sleep and depression by completing the Pittsburgh Sleep Quality Index (PSQI) and the Center for Epidemiological Studies Depression (CES-D) questionnaires. Mean CES-D scores were assessed across quintiles of PSQI. As PSQI scores increased, reflecting poorer sleep quality, CES-D scores also increased significantly indicating an increase in depression symptoms as sleep quality worsens. This trend held for both male and female officers. Mean CES-D scores across quintiles ranged from 4.72 to 12.65 in men and from 5.53 to 12.63 in women. Multivariate adjustment only very slightly attenuated the association in female officers. After adjustmnent, five of th...

Research paper thumbnail of Obesity and Work-Site Injury: The National Health Interview Survey (NHIS), 2004-2012

Annals of Epidemiology, 2014

Research paper thumbnail of Shift Work and Occupational Stress in Police Officers

Safety and Health at Work, 2014

Research paper thumbnail of Police Stress and Posttraumatic Stress Disorder: The Role of Coping

Annals of Epidemiology, 2014

Purpose: We investigated the cross-sectional associations between police stress and posttraumatic... more Purpose: We investigated the cross-sectional associations between police stress and posttraumatic stress disorder (PTSD) symptoms, and the role of coping. Methods: A total score from PTSD Checklist-Civilian Version (PCL-C), a 17-item self-report questionnaire, was used for PTSD assessment in 342 officers. Job stress was assessed using the 60-item Spielberger Police Stress Survey. Mean stress indices were computed by averaging the products of the stress rating (0-100) and frequency (events occurring in the previous year to the date of examination) for total and stress subscales including administrative pressure, physical/psychological threats, and lack of support. Active and passive coping scores were derived from the Brief COPE. Simple and multiple linear regression models were used in the analyses. Results: PTSD symptoms were positively associated with total stress (B=0.016, p<0.001) and each stress subscale (administrative pressure: B=0.012, p<0.001; physical/psychological threats: B=0.013, p<0.001; lack of support: B=0.016, p<0.001) after adjustment for age, gender, race/ethnicity, smoking, and alcohol. These associations were stronger in officers with a lower active coping score compared with those who had a higher active coping score, and in officers having a higher passive coping score compared with those who had a lower passive coping score.

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

Safety and health at work, 2013

To investigate the association between psychological distress and obesity among law enforcement o... more To investigate the association between psychological distress and obesity among law enforcement officers (LEOs) in the United States. 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 Prochaska's 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. 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/m(2); mild distress, 27.6 kg/m(2); and moderate/high distress, 33.1 kg/m(2); p = 0.016) after adjustment for age, race, income, and education level among female officers only. Physical activity modified the association between psychological...

Research paper thumbnail of Association of Shift Work With Physical Activity Among Police Officers

Journal of Occupational and Environmental Medicine, 2011

Objective: To examine relations of shift work with occupational, sports, and household physical a... more Objective: To examine relations of shift work with occupational, sports, and household physical activity (PA) among police officers. Methods: Selfreported 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.

Research paper thumbnail of Long Work Hours and Adiposity Among Police Officers in a US Northeast City

Journal of Occupational and Environmental Medicine, 2012

Objective: To investigate the associations between long work hours and adiposity measures in poli... more 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.

Research paper thumbnail of Risk factors for fractures among Japanese-American men: The Honolulu Heart Program and Honolulu–Asia Aging Study

Archives of Osteoporosis, 2011

Baseline risk factors were associated with fractures that developed after 29-31 years among Japan... more Baseline risk factors were associated with fractures that developed after 29-31 years among Japanese-American men. Hip fracture risk increased with increasing BMI (28% increase for 1 U increase), physical activity (7% increase for 1 U increase), and was decreased with increasing arm girth (27% decrease for 1 U increase). The objective of this study was to identify risk factors among Japanese-American men aged 45-68 years at baseline that were associated with prevalence and incidence of fractures at advanced age. We used baseline information from Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS). The HHP was a prospective study with primary focus on risk factors for cardiovascular disease. A cohort of 8,006 men of Japanese ancestry aged 45-68 years residing on Oahu was recruited in 1965 and followed for 31 years. The HAAS started in 1991 in conjunction with the HHP with a focus on age-related health conditions. Self-reported hip, spine, and forearm fracture prevalence was ascertained in 1991-1993 among 3,845 men aged 71-93 years. Incidence was obtained during the period (1994-1999) among 2,737 men aged 74-98 years. Poisson regression models were used to determine multi-variable adjusted prevalence and incidence ratios for fracture. Incident hip fracture was directly associated with baseline body mass index (BMI) and physical activity, and inversely associated with left upper arm girth. Incident spine fracture was directly associated with baseline age. Prevalent hip fracture was directly associated with baseline pack-years of smoking. Prevalent spine fracture was inversely associated with baseline education, and directly associated with standing height and use of medication for diabetes. Prevalent forearm fracture was inversely associated with baseline age, and directly associated with education. Results indicated that multiple baseline demographic lifestyle and anthropometric characteristics predict fracture risk at advanced age. In addition, associations varied by fracture location.

Research paper thumbnail of Prevalence and Trends of Obesity by US Occupational Group: The National Health Interview Survey (NHIS), 2004-2011

Annals of Epidemiology, 2013

Research paper thumbnail of Association Between Psychological Distress and Body Mass Index Among Law Enforcement Officers: the National Health Interview Survey (NHIS) Data (2004-2010)

Annals of Epidemiology, 2012

To investigate the association between psychological distress and obesity among law enforcement o... more 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)(2005)(2006)(2007)(2008)(2009)(2010). We used Prochaska's 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/m 2 ; mild distress, 27.6 kg/m 2 ; and moderate/high distress, 33.1 kg/m 2 ; 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/m 2 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.

Research paper thumbnail of Authors' response to the letter to the editor: “Definition of sleep duration and carotid artery intima media thickness: Caution for risk assessment”

American Journal of Industrial Medicine, 2014

Research paper thumbnail of Associations of objectively measured and self-reported sleep duration with carotid artery intima media thickness among police officers

American Journal of Industrial Medicine, 2013

We aimed to examine the association of objectively measured and self-reported sleep duration with... more 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). 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. 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. Attainment of sufficient sleep duration may be considered as a possible strategy for atherosclerosis prevention among police officers.

Research paper thumbnail of Prevalence of Obesity by Occupation Among US Workers

Journal of Occupational and Environmental Medicine, 2014

Objective: To estimate the prevalence of obesity and the change of prevalence of obesity between ... more 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/m 2 ). 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 (bluecollar) occupations. Conclusions: Workers in all occupational categories are appropriate targets for health promotion and intervention programs to reduce obesity.

Research paper thumbnail of Association of perceived stress with sleep duration and sleep quality in police officers

International journal of emergency mental health

The objective was to investigate associations ofperceived stress with sleep duration and quality ... more The objective was to investigate associations ofperceived stress with sleep duration and quality among 430 police officers. Perceived stress was assessed using the perceived stress scale. Sleep duration and quality were assessed using the Pittsburg sleep quality index questionnaire. Mean hours of sleep were determined across quartiles of perceived stress using ANOVA/ANCOVA. Logistic regression was used to obtain odds ratios and 95% confidence intervals for poor sleep quality across perceived stress quartiles. Mean age was 42.1 years. Perceived stress was inversely associated with sleep duration among certain groups: men (p = 0.004), higher-ranked officers (p = 0.002), those with higher depressive symptoms (p 0.097), no military experience (p = 0.006), and higher workload (p = 0.003). Gender, police rank, depressive symptoms, and workload each significantly modified the association between stress and sleep duration. Prevalence of poor sleep quality increased with higher levels of per...

Research paper thumbnail of Association of sleep quality with depression in police officers

International journal of emergency mental health, 2011

Poor sleep quality has been shown to adversely affect neurobehavior including an increase in depr... more Poor sleep quality has been shown to adversely affect neurobehavior including an increase in depression symptoms. Police officers are at increased risk of poor sleep quality due to occupational factors. This study analyzed self-reported sleep and depression data from police officers; 391 police officers from Buffalo, New York reported on sleep and depression by completing the Pittsburgh Sleep Quality Index (PSQI) and the Center for Epidemiological Studies Depression (CES-D) questionnaires. Mean CES-D scores were assessed across quintiles of PSQI. As PSQI scores increased, reflecting poorer sleep quality, CES-D scores also increased significantly indicating an increase in depression symptoms as sleep quality worsens. This trend held for both male and female officers. Mean CES-D scores across quintiles ranged from 4.72 to 12.65 in men and from 5.53 to 12.63 in women. Multivariate adjustment only very slightly attenuated the association in female officers. After adjustmnent, five of th...

Research paper thumbnail of Obesity and Work-Site Injury: The National Health Interview Survey (NHIS), 2004-2012

Annals of Epidemiology, 2014

Research paper thumbnail of Shift Work and Occupational Stress in Police Officers

Safety and Health at Work, 2014

Research paper thumbnail of Police Stress and Posttraumatic Stress Disorder: The Role of Coping

Annals of Epidemiology, 2014

Purpose: We investigated the cross-sectional associations between police stress and posttraumatic... more Purpose: We investigated the cross-sectional associations between police stress and posttraumatic stress disorder (PTSD) symptoms, and the role of coping. Methods: A total score from PTSD Checklist-Civilian Version (PCL-C), a 17-item self-report questionnaire, was used for PTSD assessment in 342 officers. Job stress was assessed using the 60-item Spielberger Police Stress Survey. Mean stress indices were computed by averaging the products of the stress rating (0-100) and frequency (events occurring in the previous year to the date of examination) for total and stress subscales including administrative pressure, physical/psychological threats, and lack of support. Active and passive coping scores were derived from the Brief COPE. Simple and multiple linear regression models were used in the analyses. Results: PTSD symptoms were positively associated with total stress (B=0.016, p<0.001) and each stress subscale (administrative pressure: B=0.012, p<0.001; physical/psychological threats: B=0.013, p<0.001; lack of support: B=0.016, p<0.001) after adjustment for age, gender, race/ethnicity, smoking, and alcohol. These associations were stronger in officers with a lower active coping score compared with those who had a higher active coping score, and in officers having a higher passive coping score compared with those who had a lower passive coping score.

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

Safety and health at work, 2013

To investigate the association between psychological distress and obesity among law enforcement o... more To investigate the association between psychological distress and obesity among law enforcement officers (LEOs) in the United States. 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 Prochaska's 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. 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/m(2); mild distress, 27.6 kg/m(2); and moderate/high distress, 33.1 kg/m(2); p = 0.016) after adjustment for age, race, income, and education level among female officers only. Physical activity modified the association between psychological...

Research paper thumbnail of Association of Shift Work With Physical Activity Among Police Officers

Journal of Occupational and Environmental Medicine, 2011

Objective: To examine relations of shift work with occupational, sports, and household physical a... more Objective: To examine relations of shift work with occupational, sports, and household physical activity (PA) among police officers. Methods: Selfreported 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.

Research paper thumbnail of Long Work Hours and Adiposity Among Police Officers in a US Northeast City

Journal of Occupational and Environmental Medicine, 2012

Objective: To investigate the associations between long work hours and adiposity measures in poli... more 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.

Research paper thumbnail of Risk factors for fractures among Japanese-American men: The Honolulu Heart Program and Honolulu–Asia Aging Study

Archives of Osteoporosis, 2011

Baseline risk factors were associated with fractures that developed after 29-31 years among Japan... more Baseline risk factors were associated with fractures that developed after 29-31 years among Japanese-American men. Hip fracture risk increased with increasing BMI (28% increase for 1 U increase), physical activity (7% increase for 1 U increase), and was decreased with increasing arm girth (27% decrease for 1 U increase). The objective of this study was to identify risk factors among Japanese-American men aged 45-68 years at baseline that were associated with prevalence and incidence of fractures at advanced age. We used baseline information from Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS). The HHP was a prospective study with primary focus on risk factors for cardiovascular disease. A cohort of 8,006 men of Japanese ancestry aged 45-68 years residing on Oahu was recruited in 1965 and followed for 31 years. The HAAS started in 1991 in conjunction with the HHP with a focus on age-related health conditions. Self-reported hip, spine, and forearm fracture prevalence was ascertained in 1991-1993 among 3,845 men aged 71-93 years. Incidence was obtained during the period (1994-1999) among 2,737 men aged 74-98 years. Poisson regression models were used to determine multi-variable adjusted prevalence and incidence ratios for fracture. Incident hip fracture was directly associated with baseline body mass index (BMI) and physical activity, and inversely associated with left upper arm girth. Incident spine fracture was directly associated with baseline age. Prevalent hip fracture was directly associated with baseline pack-years of smoking. Prevalent spine fracture was inversely associated with baseline education, and directly associated with standing height and use of medication for diabetes. Prevalent forearm fracture was inversely associated with baseline age, and directly associated with education. Results indicated that multiple baseline demographic lifestyle and anthropometric characteristics predict fracture risk at advanced age. In addition, associations varied by fracture location.

Research paper thumbnail of Prevalence and Trends of Obesity by US Occupational Group: The National Health Interview Survey (NHIS), 2004-2011

Annals of Epidemiology, 2013

Research paper thumbnail of Association Between Psychological Distress and Body Mass Index Among Law Enforcement Officers: the National Health Interview Survey (NHIS) Data (2004-2010)

Annals of Epidemiology, 2012

To investigate the association between psychological distress and obesity among law enforcement o... more 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)(2005)(2006)(2007)(2008)(2009)(2010). We used Prochaska's 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/m 2 ; mild distress, 27.6 kg/m 2 ; and moderate/high distress, 33.1 kg/m 2 ; 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/m 2 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.

Research paper thumbnail of Authors' response to the letter to the editor: “Definition of sleep duration and carotid artery intima media thickness: Caution for risk assessment”

American Journal of Industrial Medicine, 2014

Research paper thumbnail of Associations of objectively measured and self-reported sleep duration with carotid artery intima media thickness among police officers

American Journal of Industrial Medicine, 2013

We aimed to examine the association of objectively measured and self-reported sleep duration with... more 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). 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. 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. Attainment of sufficient sleep duration may be considered as a possible strategy for atherosclerosis prevention among police officers.

Research paper thumbnail of Prevalence of Obesity by Occupation Among US Workers

Journal of Occupational and Environmental Medicine, 2014

Objective: To estimate the prevalence of obesity and the change of prevalence of obesity between ... more 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/m 2 ). 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 (bluecollar) occupations. Conclusions: Workers in all occupational categories are appropriate targets for health promotion and intervention programs to reduce obesity.