A validation study comparing two self-reported upper extremity symptom surveys with clinical examinations for upper extremity musculoskeletal disorders.

OBJECTIVE: Evaluate the validity of two self-report symptoms surveys with two disorder classification protocols. PARTICIPANTS: 100 graduate students at a private school in the Southwest United States. METHODS: Study participants completed two self-report upper extremity musculoskeletal symptoms surveys: a nine item 10 cm Visual Analogue Scale (VAS) and a nine item Likert categorical scale anchored from "None" to "Very severe". Clinical examinations were administered using two musculoskeletal disorder classification protocols. RESULTS: For the nine body regions, concordance between the two self-report symptoms scales ranged from 0.49-0.75. Overall there was greater than 80% agreement for the two disorder classification protocols. Using either symptom survey with either disorder classification protocol provided high sensitivities and specificities (Youden's J ≥ 0.70). Three of possible six symptom survey/classification protocol pairings provided high sensitivities and specificities across all disorder groups. CONCLUSION: In this graduate student sample, none of the self-report symptom survey-classification protocol pairings was demonstratively more useful than any other pairing for studies of musculoskeletal disorders among computer users.

Mechanical systems versus smoking bans for secondhand smoke control.

INTRODUCTION: Despite international efforts to implement smoking bans, several national legislations still allow smoking and recommend mechanical systems, such as ventilation and air extraction, to eliminate secondhand smoke (SHS) health-related risks. We aimed to quantify the relative contribution of mechanical systems and smoking bans to SHS elimination. METHODS: A cross-sectional study was conducted in randomly selected establishments from 4 Mexican cities (3 with no ban). SHS exposure was assessed using nicotine passive monitors. Establishment characteristics, presence of mechanical systems, and enforcement of smoking policies were obtained through direct observation and self-report. Multilevel models were used to assess relative contributions to SHS reduction. RESULTS: Compared with Mexico City, nicotine concentrations were 3.8 times higher in Colima, 5.4 in Cuernavaca, and 6.4 in Toluca. Mechanical systems were not associated with reduced nicotine concentrations. Concentration differences between cities were largely explained by the presence of smoking bans (69.1% difference reduction) but not by mechanical systems (-5.7% difference reduction). CONCLUSIONS: Smoking bans represent the only effective approach to reduce SHS. Tobacco control regulations should stop considering mechanical systems as advisable means for SHS reduction and opt for complete smoking bans in public places.

Associations of BMI and its fat-free and fat components with blood lipids in children: Project HeartBeat!

AIM: This study aimed to distinguish between the roles of the two components of BMI, the fat mass (FM) index and the fat-free mass (FFM) index, in BMI's association with blood lipids in children and adolescents. METHODS: A total of 678 children (49.1% female, 79.9% non-black), initially aged 8, 11 and 14 years, were followed at 4-month intervals for up to 4 years (1991-1995). Total cholesterol (TC), LDL-C, HDL-C and triglycerides were determined in fasting blood samples. FFM index and FM index were calculated as FFM (kg)/height (m)(2) and FM (kg)/height (m)(2), respectively. Using a multilevel linear model, repeated measurements of blood lipids were regressed on concurrent measures of BMI or its components, adjusting for age, sex and race and, in a subsample, also for physical activity, energy intake and sexual maturity. RESULTS: Estimated regression coefficients for the relations of TC with BMI, FFM index and FM index were 1.539, -0.606 (p > 0.05) and 3.649, respectively. When FFM index and FM index were entered into the TC model simultaneously, regression coefficients were -0.855 and 3.743, respectively. An increase in BMI was related to an increase in TC; however, an equivalent increase in FM index was related to a greater increase in TC and, when FFM index was tested alone or with FM index, an increase in FFM index was related to a decrease in TC. Similar results were observed for LDL-C. FFM index and FM index were both inversely related to HDL-C and directly to triglycerides. Compared with FFM index, the equivalent increase in FM index showed a greater decrease in HDL-C. CONCLUSION: Greater BMI was related to adverse levels of blood lipids in children and adolescents, which was mainly attributable to BMI's fat component. It is important to identify weight management strategies to halt the childhood obesity epidemic and subsequently prevent heart disease in adulthood.

Psychosocial outcomes of Lunch is in the Bag, a parent program for packing healthful lunches for preschool children.

OBJECTIVE: This pilot study evaluated effects of Lunch is in the Bag on behavioral constructs and their predictive relationship to lunch-packing behaviors of parents of young children. METHODS: Six child care centers were pair-matched and randomly assigned to intervention (n = 3) and comparison (n = 3) groups. Parent/child dyads participated. Constructs of knowledge, outcome expectations, perceived control, subjective norms, and intentions were measured by a pre/post questionnaire. Hierarchical linear regression was used, and P < .05 was considered significant. RESULTS: There were significant increases in knowledge (P = .01); outcome expectations for whole grains (P < .001); and subjective norms for fruit (P = .002), vegetables (P = .046), and whole grains (P = .02). Perceived control, outcome expectations, and intentions significantly predicted packing vegetables and knowledge predicted whole grains. CONCLUSIONS AND IMPLICATIONS: Lunch is in the Bag is a feasible intervention to improve the lunch-packing behaviors of parents of preschool-aged children.

Reductions in cigarette smoking and acute myocardial infarction mortality in Jefferson County, Texas.

After litigation against the tobacco industry ended in a settlement, the Texas legislature funded pilot projects to reduce tobacco use in selected areas of the state. Subsequent telephone surveys showed that well-funded activities were successful in reducing population rates of self-reported cigarette smoking. We present evidence that the reduction in smoking promptly led to lower rates of death from acute myocardial infarctions.

Lunch is in the bag: increasing fruits, vegetables, and whole grains in sack lunches of preschool-aged children.

Fruits, vegetables, and whole grains are important sources of nutrients for healthy growth and development of young children. Recent evidence suggests that sack lunches packed by parents for children to consume at child-care centers do not regularly meet the goal of one serving of fruit, vegetables, and whole grains. Lunch Is In The Bag is a child-care center-based nutrition education program targeted at parents of preschool-aged children to increase the number of servings of fruits, vegetables, and whole grains in sack lunches sent from home that was pilot tested in fall 2008. In a quasiexperimental design, six child-care centers were paired by size before being randomly assigned to intervention (n=3) and comparison (n=3) groups. The parents of caregivers with primary responsibility for preparing the sack lunches of the 3- to 5-year-old children attending the centers were enrolled as parent-child dyads. The intervention included parent handouts, classroom activities, education stations, and teacher training. The contents of the lunch sacks for both the intervention group and comparison group were recorded for 3 nonconsecutive days before and immediately after the intervention period to measure the number of servings of fruits, vegetables, and whole grains. A total of 132 parent-child dyads completed the study, 81 in the intervention group and 51 in the comparison group. Direct observation of children's lunches from the intervention group showed an increase in predicted mean number of servings of vegetables, from 0.41 to 0.65 (P<0.001) and whole grains, from 0.54 to 1.06 (P<0.001). No significant difference was observed in the mean number of servings of fruit. Lunch Is In The Bag, which is designed to fit in the child-care environment and targets parents of 3- to 5-year-old children, is a feasible intervention for improving the nutritional quality of sack lunches.

The cultural production of health inequalities: a cross-sectional, multilevel examination of 52 countries.

In a 2001 report, the U.S. National Institutes of Health called for more integration of the social sciences into health-related research, including research guided by theories and methods that take social and cultural systems into consideration. Based on a theoretical framework that integrates Hofstede's cultural dimensions with sociological theory, the authors used multilevel modeling to explore the association of culture with structural inequality and health disparities. Their results support the idea that cultural dimensions and social structure, along with economic development, may account for much of the cross-national variation in the distribution of health inequalities. Sensitivity tests also suggest that an interaction between culture and social structure may confound the relationship between income inequality and health. It is necessary to identify important cultural and social structural characteristics before we can achieve an understanding of the complex, dynamic systems that affect health, and develop culturally sensitive interventions and policies. This study takes a step toward identifying some of the relevant cultural and structural influences. More research is needed to explore the pathways leading from the sociocultural environment to health inequalities.

Analytic methods in Project HeartBeat!

Project HeartBeat! (1991-1995) was an observational study of the development of cardiovascular disease (CVD) risk factors in childhood and adolescence using an accelerated longitudinal design. The purpose of this paper is to explain the analytic methods used in the study, particularly multilevel statistical models. Measurements of hemodynamic, lipid, anthropometric, and other variables were obtained in 678 children who were enrolled in three cohorts (baseline ages 8, 11, and 14 years) and followed for 4 years, resulting in data for children aged 8-18 years. Patterns of change of blood pressure, serum lipid concentration, and obesity with age, race, and gender were of particular interest. The design specified 12 measurements of each outcome variable per child. Multilevel models were used to account for correlations resulting from repeated measurements on individuals and to allow use of data from incomplete cases. Data quality-control measures are described, and an example of multilevel analysis in Project HeartBeat! is presented. Multilevel models were also used to show that there were no differences attributable to the cohorts, and combining data from the three age cohorts was judged to be reasonable. Anthropometric data were compared with national norms and shown to have similar patterns; thus, the patterns seen in the CVD risk factors may be generalized, with some caveats, to the U.S. population of children.

Trajectories of fat mass index, fat free-mass index, and waist circumference in children: Project HeartBeat!

BACKGROUND: Body composition and fat distribution change dramatically during adolescence. Data based on longitudinal studies to describe these changes are limited. The aim of this study was to describe age-related changes in fat free-mass index (FFMI) and fat mass index (FMI), which are components of BMI, and waist circumference (WC) in participants of Project HeartBeat!, a longitudinal study of children. METHODS: Anthropometric measurements and body composition data were obtained in a mixed longitudinal study of 678 children (49.1% female, 20.1% black), initially aged 8, 11, and 14 years, every 4 months for 4 years (1991-1995). Trajectories of change from ages 8 to 18 years were measured for FFMI, FMI, and WC. Because of the small number of observations for black participants, trajectories for this group were limited to ages 8.5-15 years. RESULTS: Body mass index, FFMI, and WC increased steadily with age for all race-gender cohorts. However, in nonblack girls, FFMI remained constant after about age 16 years. For black boys and girls, FFMI was similar at age 8.5 years but increased more steeply for black boys by age 15 years. In girls, FMI showed an upward trend until shortly after age 14 years, when it remained constant. In boys, FMI increased between age 8 years and age 10 years, and then decreased. CONCLUSIONS: The extent to which each component of BMI contributes to the changes in BMI depends on the gender, race, and age of the individual. Healthcare providers need to be aware that children who show upward deviation of BMI or BMI percentiles may have increases in their lean body mass rather than in adiposity.

Blood lipids in children: age-related patterns and association with body-fat indices: Project HeartBeat!

BACKGROUND: Longitudinal data on the normal development of blood lipids and its relationships with body fatness in children and adolescents are limited. Objectives of the current analysis were to estimate trajectories related to age for four blood lipid components and to examine the impact of change in body fatness on blood lipid levels, comparing estimated effects among adiposity indices, in children and adolescents. METHODS: Three cohorts, with a total of 678 children (49.1% female, 79.9% nonblack) initially aged 8, 11, and 14 years, were followed at 4-month intervals (1991-1995). Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels were determined in blood samples taken following fasting. Body fatness was measured by five adiposity indices-BMI; percent body fat (PBF); abdominal circumference; and the sums of six and of two skinfold thicknesses. Trajectories of change in blood lipid levels from ages 8 to 18 years were estimated by gender and race. The impact of change in body fatness on lipid levels was evaluated for each index, adjusting for gender, race, and age. RESULTS: All lipid components varied significantly with age. Total cholesterol decreased by approximately 19 mg/dL from ages 9 to 16 years in girls and more steeply from ages 10 to 17 years in boys. LDL-C decreased monotonically, more steeply in boys than in girls. It was higher among nonblacks than among blacks. HDL-C increased monotonically in girls, mainly from ages 14 to 18 years, but fluctuated sharply among boys. Levels of HDL-C were higher among blacks than among nonblacks. The levels of triglycerides increased from ages 8 to 12 years among girls and, almost linearly, from ages 8 to 18 years among boys. The levels of triglycerides were higher among nonblacks than among blacks. Increase in body fatness was significantly associated with increases in total cholesterol, LDL-C, and triglyceride levels. Significant interactions between the adiposity indices (except for BMI) and gender indicated smaller impacts of change in body fatness on total cholesterol and LDL-C in girls than in boys. The estimated impact on triglycerides was weaker among blacks than among nonblacks, except for PBF. Change in body fatness was negatively associated with HDL-C. The results remained essentially unchanged after adjustments for energy intake, physical activity, and sexual maturation. CONCLUSIONS: Patterns of change with age in blood lipid components vary significantly among gender and racial groups. Increase in body fatness among children is consistently associated with adverse change in blood lipids. Evaluation of blood lipid level should take into account variation by age, gender, and race. Intervention through body-fat control should help prevent adverse lipid levels in children and adolescents.

Sexual maturation affects diet-blood total cholesterol association in children: Project HeartBeat!

BACKGROUND: Cardiovascular disease (CVD) does not become clinically manifest until adulthood. However, children and young adults have evidence of atheromatous lesions and fatty streaks in their aortas and coronary vessels. Most longitudinal studies in children are not designed to evaluate the dynamics of change in CVD risk factors. There is a need to describe the trajectory of CVD risk factors as growth processes, to better understand their relationships. This study assesses the associations between dietary variables and blood total cholesterol concentration (BTCC) among children and adolescents aged 8-18 years after adjustment for sexual maturation. METHODS: There were 678 boys and girls aged 8, 11, and 14 years at baseline who were followed for up to 4 years, allowing the creation of a synthetic cohort analytically, from ages 8-18 years. Multilevel modeling was used to longitudinally assess BTCC, dietary intake, Tanner stage, and BMI. RESULTS: For every 1-mg/day increase in dietary cholesterol, BTCC increased by 0.012 mg/dL. However, no associations were evident between BTCC and dietary total fat, saturated fatty acids, polyunsaturated fatty acids, or monounsaturated fatty acids. In girls, none of the dietary variables was significantly associated with BTCC after controlling for Tanner stage for breast. In boys, with the exception of dietary cholesterol, no other dietary variable was significantly associated with BTCC after controlling for Tanner stage for genitalia. CONCLUSIONS: Sexual maturation exerts a strong influence on BTCC in children and adolescents aged 8-18 years, obscuring most associations between diet and BTCC. The inclusion of sexual maturity stage is important in studies of blood lipids among children and adolescents.

Systolic and fourth- and fifth-phase diastolic blood pressure from ages 8 to 18 years: Project HeartBeat!

BACKGROUND: Systolic and fourth-phase and fifth-phase diastolic blood pressure (SBP, DBP4, DBP5) have appeared to differ in their patterns of age-related change, and SBP and DBP5 differ in their respective associations with anthropometric variables. Project HeartBeat! investigated trajectories of change in SBP, DBP4, and SBP5 with age and their relationships with indices of adiposity, controlling for energy intake, physical activity, and sexual maturation. METHODS: Project HeartBeat! was a mixed longitudinal study in 678 black and white girls and boys aged 8, 11, or 14 years at first examination, followed at 4-month intervals for up to 4 years (1991-1995). A statistical model was estimated for the trajectory of change in each blood pressure measure from ages 8 to 18 years. RESULTS: For SBP, DBP4, and DBP5, the trajectories were sigmoid, parabolic, and linear in form, respectively. SBP and DBP4 differed significantly by gender; DBP4 and DBP5 were significantly related to race. Adjusted for age, gender, and race, all relationships of adiposity-related variables (percent body fat, abdominal circumference, skinfold thickness, and BMI and its fat and fat-free components) with SBP were positive and significant. Corresponding relationships for DBP4 were notably weaker but significant, and for DBP5, weak or not significant. After adjusting for diet, physical inactivity, and maturation, no DBP5 relationship with adiposity indices remained significant. CONCLUSIONS: SBP, DBP4, and DBP5 are distinct in patterns of change with age, relationships to gender and race, and patterns of association with multiple anthropometric indices related to adiposity.

Effects of body size and body fatness on left ventricular mass in children and adolescents: Project HeartBeat!

BACKGROUND: Left ventricular mass (LVM) is a strong predictor of cardiovascular disease in adults. Available study findings on effects of body fatness on LVM in children are inconsistent. Understanding the impact of body fat on LVM in children may help prevent excessive LVM through measures to reduce overweight and obesity. METHODS: Healthy children (n=678) aged 8, 11, and 14 years at baseline were examined at 4-month intervals for up to 4 years (1991-1995); 4608 valid measurements of LVM were obtained with M-mode echocardiography. A multilevel linear model was used for analysis. The impact of body size was examined by adding separately nine body-size indicators to a basic LVM-gender-age model. The impact of body fatness was tested by introducing four body-fatness indicators into the nine models, yielding 36 models. RESULTS: All body-size indicators showed strong, positive effects on LVM. In models containing weight or body surface area (measuring both fat-free and fat contributions to body size), additional effects of body fatness were negative; in models containing fat-free mass (FFM) or height (both measuring body size independent of body fat), increased body fatness was related to a significant increase in LVM. For example, in models with FFM as a body-size indicator, a 1-SD increase in percent body fat or fat mass was related to a 5.4- or 7.2-g increase in LVM, respectively. CONCLUSIONS: Effects of body size on LVM attributable to fat-free body mass can be distinguished from those attributable to fat body mass; both are independent, positive predictors, but the former is the stronger determinant. When a body-size indicator not independent of body fat is used as a predictor, effects of fat-free body mass and fat body mass are forced to relate to the same indicator; because their magnitudes are estimated to be equal, the effect of fat body mass is overestimated. Thus, when an additional body-fatness indicator is included in the prediction of LVM, the additional estimated effect related to the indicator appears to be negative.

The epidemiology of upper extremity musculoskeletal symptoms on a college campus.

OBJECTIVE: The study examines temporal variations in upper-extremity musculoskeletal symptoms throughout the day, over a week and throughout the semester. METHODS: 30 undergraduates were followed in a repeated measures study throughout a semester. Upper extremity musculoskeletal symptoms data were collected on handheld computers randomly throughout the day for seven days over three data collection periods. Multilevel statistical models evaluated associations between time-related predictors and symptoms. RESULTS: In adjusted models, pain reported at baseline was associated with increased odds of experiencing both any symptoms (OR=15.64; 90% CI 7.22-33.88) and moderate or greater symptoms (OR=16.44; 90% CI 4.57-29.99). Any symptoms were less likely to be reported if responses occurred at 58-76 days (OR=0.66; 90% CI 0.49-0.86), 77-90 days (OR=0.29; 90% CI 0.20-0.42) and 91-117 days (OR=0.54; 90% CI 0.39-0.75) into the semester compared to 35-57 days. Similarly, responding after midnight was associated with greater odds of reporting moderate or greater symptoms (OR=21.33; 90% CI 6.49-65.97). There was no association observed for day of week and symptoms. CONCLUSION: This pilot work suggests upper extremity musculoskeletal symptoms exhibit temporal variations related to time of day and days into semester. Understanding the natural history of musculoskeletal symptoms and disorders is needed when designing epidemiologic research and/or intervention studies using symptom outcome measures.

Evaluation of two posture survey instruments for assessing computing postures among college students.

OBJECTIVE: To determine agreement between two posture assessment survey instruments and which, if any, were correlated with experiencing upper extremity musculoskeletal symptoms. METHODS: Thirty undergraduate participants had three postural assessment surveys completed, one each for three separate 7-day data collection periods during a semester. Two observation assessment tools were used, a modified Rapid Upper Limb Assessment (mRULA) for computer users for the right and left limbs and the University of California Computer Use Checklist. Concurrently, upper extremity musculoskeletal symptom experience paired to each postural assessment was measured. Lin's concordance correlation coefficient evaluated survey agreement and multi-level statistical models described associations between survey responses and symptoms. RESULTS: There was no agreement between the two postural assessment tool scores (p> 0.85). In adjusted models, the UC Computer Use Checklist was positively associated with symptoms occurrence (OR=1.4, 90% CI 1.2-1.6 for any symptoms; OR=1.3, 90% CI 1.0-1.6 for moderate or greater symptoms). Associations with mRULA scores were inconsistent in that they were sometimes protective and sometimes indicators of risk, depending on the covariates included in the models. CONCLUSION: The mRULA for computer users and the UC Computer Use Checklist were independent of each other; however, due to the inconsistent associations with symptoms we cannot conclude one instrument is superior to the other. Our data do suggest the UC Computer Use Checklist demonstrates a traditional relationship with symptoms, where increasing scores signifiy greater risk. We observed a nontraditional relatioship with symptoms for the mRULA for computer users that needs to be further examined. This is a pilot study and, thus, findings should be interpreted as exploratory. Associations observed in the current study will be used to test hypotheses in the cohort study recently conducted.

Upper extremity pain and computer use among engineering graduate students: a replication study.

BACKGROUND: Recent literature identified upper extremity musculoskeletal symptoms at a prevalence of >40% in college populations. The study objectives were to determine weekly computer use and the prevalence of upper extremity musculoskeletal symptoms in a graduate student population, and make comparisons with previous graduate and undergraduate cohorts. METHODS: One hundred sixty-six graduate students completed a survey on computing and musculoskeletal health. Associations between individual factors and symptom status, functional limitations, academic impact, medication use, and health services utilization were determined. Logistic regression analyses evaluated the association between symptom status and computing. Cross-study comparisons were made. RESULTS: More symptomatic participants experienced functional limitations than asymptomatic participants (74% vs. 32%, P < 0.001) and reported medication use for computing pain (34% vs. 10%, P < 0.01). More participants who experienced symptoms within an hour of computing used health services compared to those who experienced symptoms after an hour of computer use (60% vs. 12%, P < 0.01). Years of computer use (OR = 1.59, 95% CI 1.05-2.40) and number of years in school where weekly computer use was more than 10 hr (OR = 1.56, 95% CI 1.04-2.35) were associated with pain within an hour of computing. Cross-study comparisons found college populations more similar than different. CONCLUSION: The overall findings reinforced previous literature documenting the prevalence of upper extremity musculoskeletal symptoms in college populations, suggesting an important population for participating in public health interventions designed to support healthy computing practices and identify risk factors important to evaluate in future cohort studies. Am. J. Ind. Med. 52:113-123, 2009. (c) 2008 Wiley-Liss, Inc.

Computer use patterns associated with upper extremity musculoskeletal symptoms.

INTRODUCTION: Over half of surveyed college students are experiencing pain they are attributing to computer use. The study objective was to evaluate the effect of computing patterns on upper extremity musculoskeletal symptoms. METHODS: Symptom experiences and computing/break patterns were reported several times daily over three weeks for 30 undergraduate students over a semester. Two-level logistic regression models described the daily association between each computing pattern and both any and moderate or greater symptom experienced, adjusting for covariates. RESULTS: The associations between most computing/break patterns and experiencing any symptoms were positive: total hours of computer use adjOR = 1.1 (90% CI 1.1-1.2), 1-2 breaks versus none adjOR = 1.3 (90% CI 0.9-1.9), 3-6 breaks versus none adjOR = 1.5 (90% CI 1.1-2.2), >15 min break versus none adjOR = 1.6 (90% CI 1.1-2.2), and number of stretch breaks adjOR = 1.3 (90% CI 1.1-1.5). However, breaks for less than 15 min were negatively associated with experiencing any symptoms: adjOR = 0.6 (90% CI 0.5-0.9). The associations between most computing/break patterns and experiencing moderate or greater symptoms were positive: total hours of computer use OR = 1.1 (90% CI 1.1-1.2), 1-2 breaks and 5-6 breaks versus none OR = 1.8 (90% CI 1.1-2.9), 7-8 breaks versus none OR = 2.0 (1.0-4.2), >15 min break versus none 1.8 (1.1-3.1), and number of stretch breaks OR = 1.3 (1.0-1.5). CONCLUSION: Computing/break patterns were consistently associated with experiencing symptoms. Our findings suggest evaluating breaks with computing duration (computing patterns) is more informative than assessing computing duration alone and can be used to better design ergonomic training programs for student populations that incorporate break times.

Social capital, income inequality, and self-rated health in 45 countries.

There has been growing interest in the relationship between the social environment and health. Among the concepts that have emerged over the past decade to examine this relationship are socio-economic inequality and social capital. Using data from the World Values Survey and the World Bank, we tested the hypothesis that self-rated health is affected by social capital and income inequality cross-nationally. The merit of our approach was that we used multilevel methods in a larger and more diverse sample of countries than used previously. Our results indicated that, for a large number of diverse countries, commonly used measures of social capital and income inequality had strong compositional effects on self-rated health, but inconsistent contextual effects, depending on the countries included. Cross-level interactions suggested that contextual measures can moderate the effect of compositional measures on self-rated health. Sensitivity tests indicated that effects varied in different subsets of countries. Future research should examine country-specific characteristics, such as differences in cultural values or norms, which may influence the relationships between social capital, income inequality, and health.

Drinking social norms and drinking behaviours: a multilevel analysis of 137 workgroups in 16 worksites.

BACKGROUND: Previous studies on worksite drinking norms showed individually perceived norms were associated with drinking behaviours. OBJECTIVE: To examine whether restrictive drinking social norms shared by workgroup membership are associated with decreased heavy drinking, frequent drinking and drinking at work at the worker level. METHODS: The sample included 5338 workers with complete data nested in 137 supervisory workgroups from 16 American worksites. Multilevel models were fitted to examine the association between workgroup drinking norms and heavy drinking, frequent drinking and drinking at work. RESULTS: Multivariate adjusted models showed participants working in workgroups in the most discouraging drinking norms quartile were 45% less likely to be heavy drinkers, 54% less likely to be frequent drinkers and 69% less likely to drink at work than their counterparts in the most encouraging quartile. CONCLUSIONS: Strong associations between workgroup level restrictive drinking social norms and drinking outcomes suggest public health efforts at reducing drinking and alcohol-related injuries, illnesses and diseases should target social interventions at worksites.