Background The prevalence of obesity has increased substantially over the past 30 years. We performed a quantitative analysis of the nature and extent of the person-to-person spread of obesity as a possible factor contributing to the obesity epidemic. Methods We evaluated a densely interconnected social network of 12,067 people assessed repeatedly from 1971 to 2003 as part of the Framingham Heart Study. The bodymass index was available for all subjects. We used longitudinal statistical models to examine whether weight gain in one person was associated with weight gain in his or her friends, siblings, spouse, and neighbors. Results Discernible clusters of obese persons (body-mass index [the weight in kilograms divided by the square of the height in meters], ≥30) were present in the network at all time points, and the clusters extended to three degrees of separation. These clusters did not appear to be solely attributable to the selective formation of social ties among obese persons. A person’s chances of becoming obese increased by 57% (95% confidence interval [CI], 6 to 123) if he or she had a friend who became obese in a given interval. Among pairs of adult siblings, if one sibling became obese, the chance that the other would become obese increased by 40% (95% CI, 21 to 60). If one spouse became obese, the likelihood that the other spouse would become obese increased by 37% (95% CI, 7 to 73). These effects were not seen among neighbors in the immediate geographic location. Persons of the same sex had relatively greater influence on each other than those of the opposite sex. The spread of smoking cessation did not account for the spread of obesity in the network. Conclusions Network phenomena appear to be relevant to the biologic and behavioral trait of obesity, and obesity appears to spread through social ties. These findings have implications for clinical and public health interventions.

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The Spread of Obesity in a Large Social Network over 32 Years

cording to the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, criteria; and (3) either. Results: Of 393 eligible patients, 243 (62%) completed AUDIT-C and interviews. For detecting heavy drinking, AUDIT-C had a higher AUROC than the full AUDIT (0.891 vs 0.881; P = .03). Although the full AUDIT performed better than AUDIT-C for detecting active alcohol abuse or dependence (0.811 vs 0.786; P<.001), the 2 questionnaires performed similarly for detecting heavy drinking and/or active abuse or dependence (0.880 vs 0.881).

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/208954/ioi70602.pdf

The AUDIT Alcohol consumption questions (AUDIT-C) : An effective brief screening test for problem drinking

Offering a unifying theoretical perspective not readily available in any other text, this innovative guide to econometrics uses simple geometrical arguments to develop students' intuitive understanding of basic and advanced topics, emphasizing throughout the practical applications of modern theory and nonlinear techniques of estimation. One theme of the text is the use of artificial regressions for estimation, reference, and specification testing of nonlinear models, including diagnostic tests for parameter constancy, serial correlation, heteroscedasticity, and other types of mis-specification. Explaining how estimates can be obtained and tests can be carried out, the authors go beyond a mere algebraic description to one that can be easily translated into the commands of a standard econometric software package. Covering an unprecedented range of problems with a consistent emphasis on those that arise in applied work, this accessible and coherent guide to the most vital topics in econometrics today is indispensable for advanced students of econometrics and students of statistics interested in regression and related topics. It will also suit practising econometricians who want to update their skills. Flexibly designed to accommodate a variety of course levels, it offers both complete coverage of the basic material and separate chapters on areas of specialized interest.

Estimation and Inference in Econometrics

A review is presented of the book “Heuristics and Biases: The Psychology of Intuitive Judgment,” edited by Thomas Gilovich, Dale Griffin, and Daniel Kahneman.

Heuristics and Biases: The Psychology of Intuitive Judgment

Perceived discrimination has been studied with regard to its impact on several types of health effects. This meta-analysis provides a comprehensive account of the relationships between multiple forms of perceived discrimination and both mental and physical health outcomes. In addition, this meta-analysis examines potential mechanisms by which perceiving discrimination may affect health, including through psychological and physiological stress responses and health behaviors. Analysis of 134 samples suggests that when weighting each study's contribution by sample size, perceived discrimination has a significant negative effect on both mental and physical health. Perceived discrimination also produces significantly heightened stress responses and is related to participation in unhealthy and nonparticipation in healthy behaviors. These findings suggest potential pathways linking perceived discrimination to negative health outcomes.

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Perceived discrimination and health: a meta-analytic review.

Objective. —To examine the extent of binge drinking by college students and the ensuing health and behavioral problems that binge drinkers create for themselves and others on their campus. Design. —Self-administered survey mailed to a national representative sample of US 4-year college students. Setting. —One hundred forty US 4-year colleges in 1993. Participants. —A total of 17592 college students. Main Outcome Measures. —Self-reports of drinking behavior, alcohol-related health problems, and other problems. Results. —Almost half (44%) of college students responding to the survey were binge drinkers, including almost one fifth (19%) of the students who were frequent binge drinkers. Frequent binge drinkers are more likely to experience serious health and other consequences of their drinking behavior than other students. Almost half (47%) of the frequent binge drinkers experienced five or more different drinking-related problems, including injuries and engaging in unplanned sex, since the beginning of the school year. Most binge drinkers do not consider themselves to be problem drinkers and have not sought treatment for an alcohol problem. Binge drinkers create problems for classmates who are not binge drinkers. Students who are not binge drinkers at schools with higher binge rates were more likely than students at schools with lower binge rates to experience problems such as being pushed, hit, or assaulted or experiencing an unwanted sexual advance. Conclusions. —Binge drinking is widespread on college campuses. Programs aimed at reducing this problem should focus on frequent binge drinkers, refer them to treatment or educational programs, and emphasize the harm they cause for students who are not binge drinkers. (JAMA. 1994;272:1672-1677)

Health and Behavioral Consequences of Binge Drinking in College: A National Survey of Students at 140 Campuses

Abstract The 2001 Harvard School of Public Health College Alcohol Study surveyed students at 119 4-year colleges that participated in the 1993, 1997, and 1999 studies. Responses in the 4 survey years were compared to determine trends in heavy alcohol use, alcohol-related problems, and encounters with college and community prevention efforts. In 2001, approximately 2 in 5 (44.4%) college students reported binge drinking, a rate almost identical to rates in the previous 3 surveys. Very little change in overall binge drinking occurred at the individual college level. The percentages of abstainers and frequent binge drinkers increased, a polarization of drinking behavior first noted in 1997. A sharp rise in frequent binge drinking was noted among students attending all-women's colleges. Other significant changes included increases in immoderate drinking and harm among drinkers. More students lived in substance-free housing and encountered college educational efforts and sanctions resulting from their alcohol use.

Trends in College Binge Drinking during a Period of Increased Prevention Efforts. Findings from 4 Harvard School of Public Health College Alcohol Study Surveys: 1933-2001.

The 2001 Harvard School of Public Health College Alcohol Study surveyed students at 119 4-year colleges that participated in the 1993, 1997, and 1999 studies. Responses in the 4 survey years were compared to determine trends in heavy alcohol use, alcohol-related problems, and encounters with college and community prevention efforts. In 2001, approximately 2 in 5 (44.4%) college students reported binge drinking, a rate almost identical to rates in the previous 3 surveys. Very little change in overall binge drinking occurred at the individual college level. The percentages of abstainers and frequent binge drinkers increased, a polarization of drinking behavior first noted in 1997. A sharp rise in frequent binge drinking was noted among students attending all-women's colleges. Other significant changes included increases in immoderate drinking and harm among drinkers. More students lived in substance-free housing and encountered college educational efforts and sanctions resulting from their alcohol use.

https://www-static.bouldercolorado.gov/docs/journal-american-college-health-study-1-201307101733.pdf

Trends in College Binge Drinking During a Period of Increased Prevention Efforts: Findings from 4 Harvard School of Public Health College Alcohol Study Surveys: 1993–2001

In 1999, the Harvard School of Public Health College Alcohol Study resurveyed colleges that participated in the 1993 and 1997 surveys. Responses to mail questionnaires from more than 14 000 students at 119 nationally representative 4-year colleges in 39 states were compared with responses received in 1997 and 1993. Two of 5 students (44%) were binge drinkers in 1999, the same rate as in 1993. However, both abstention and frequent binge-drinking rates increased significantly. In 1999, 19% were abstainers, and 23% were frequent binge drinkers. As before, binge drinkers, and particularly frequent binge drinkers, were more likely than other students to experience alcohol-related problems. At colleges with high binge-drinking rates, students who did not binge drink continued to be at higher risk of encountering the secondhand effects of others’heavy drinking. The continuing high level of binge drinking is discussed in the context of the heightened attention and increased actions at colleges. Although it may take more time for interventions to take effect, the actions college health providers have undertaken thus far may not be a sufficient response.

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College Binge Drinking in the 1990s: A Continuing Problem

OBJECTIVE: This report estimates the numbers of 18-24 year old United States college students who annually experience alcohol-related deaths, injuries and other health problems. METHOD: We examined traffic and unintentional injury deaths in 1998 reported by the National Highway Traffic Safety Administration and the Centers for Disease Control (CDC). We also examined results of national coroner studies, Department of Education college enrollment data, the National Household Survey on Drug Abuse (NHSDA), the CDC National College Health Risk Behavior Survey and the Harvard School of Public Health College Alcohol Survey (CAS). All survey participants were ages 18-24: 6,930 college and 12,394 noncollege respondents in the NHSDA survey; 3,077 college students in the CDC survey; and 12,217 full-time 4-year college students in the CAS. Based on the number and proportion of 18-24 year olds enrolled in college, data on alcohol involvement in injury deaths among 18-24 year olds and survey responses, we calculated the numbers of 18-24 year old alcohol-related injury deaths and other health problems. RESULTS: We estimate that over 1,400 students aged 18-24 and enrolled in 2- and 4-year colleges died in 1998 from alcohol-related unintentional injuries, including motor vehicle crashes. According to surveys conducted in 1999, in the preceding year, over 2 million of the 8 million college students in the United States drove under the influence of alcohol and over 3 million rode with a drinking driver. Over 500,000 full-time 4-year college students were unintentionally injured under the influence of alcohol and over 600,000 were hit or assaulted by another student who had been drinking. CONCLUSIONS: There is an urgent need for expanding prevention and treatment programs, to reduce alcohol-related harm among U.S. college students and other young adults. Language: en

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Henry Wechsler

Papers

Health and Behavioral Consequences of Binge Drinking in College: A National Survey of Students at 140 Campuses

Trends in College Binge Drinking during a Period of Increased Prevention Efforts. Findings from 4 Harvard School of Public Health College Alcohol Study Surveys: 1933-2001.

Trends in College Binge Drinking During a Period of Increased Prevention Efforts: Findings from 4 Harvard School of Public Health College Alcohol Study Surveys: 1993–2001

College Binge Drinking in the 1990s: A Continuing Problem

Magnitude of alcohol-related mortality and morbidity among U.S. college students ages 18-24.