Predictors of Subgroups Based on Maximum Drinks per Occasion Over Six Years for 833 Adolescents and Young Adults in COGA
ABSTRACT Objective: A person's pattern of heavier drinking often changes over time, especially during the early drinking years, and reflects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations. Method: The patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identified latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership. Results: Four latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers. Conclusions: Four trajectory classes were observed and were best predicted by a combination of items that reflected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes. (J. Stud. Alcohol Drugs, 75, 24-34, 2014).
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ABSTRACT: Background Alcohol-related blackouts (ARBs) are reported by ~50% of drinkers. While much is known about the prevalence of ARBs in young adults and their cross-sectional correlates, there are few prospective studies regarding their trajectories over time during mid-adolescence. This paper reports latent trajectory classes of ARBs between age 15 and 19, along with predictors of those patterns.Methods Latent class growth analysis (LCGA) was used to evaluate the pattern of occurrence of ARBs across 4 time points for 1,402 drinking adolescents from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multinomial regression analyses evaluated age-15 demography, substance-related items, externalizing characteristics, and estimated peer substance use as predictors of latent class membership.ResultsARBs were reported at age 15 in 30% and at age 19 in 74% of these subjects. Four latent trajectory classes were identified: Class 1 (5.1%) reported no blackouts; for Class 2 (29.5%), ARBs rapidly increased with age; for Class 3 (44.9%), blackouts slowly increased; and for Class 4 (20.5%), ARBs were consistently reported. Using Class 2 (rapid increasers) as the reference, predictors of class membership included female sex, higher drinking quantities, smoking, externalizing characteristics, and estimated peer substance involvement (pseudo R2 = 0.22).ConclusionsARBs were common and repetitive in these young subjects, and predictors of their trajectories over time involved multiple domains representing diverse characteristics.Alcoholism Clinical and Experimental Research 12/2014; 39(1). DOI:10.1111/acer.12601 · 3.31 Impact Factor
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ABSTRACT: A novel avian influenza A(H7N9) virus, first identified in Mainland China in February and March 2013, caused an outbreak in humans in April and May, 2013. Closure of live poultry markets in some affected cities dramatically reduced numbers of cases during summer of 2013, but the epidemic resurged during the winter 2013-14, increasing reported cases to 393 in Mainland China as of 30 March 2014. The study aimed to explore population behavior patterns responding to an epidemic of influenza A(H7N9) virus. Three cross-sectional surveys were conducted among 1000, 680, and 1011 respondents in December 2013, January 2014, and February 2014, with response rates of 68.0, 64.4, and 66.6 %, respectively, in Hong Kong. Adults were recruited and interviewed using random digit-dialing telephone survey. Latent class analysis was employed to explore heterogeneity in protective behavior patterns across the three surveys. Multinomial regression models were developed to determine factors associated with latent class membership. Three comparable latent classes were identified across the three surveys: Moderate hygiene compliance (Class 1), High hygiene compliance (Class 2), and Vigilance (Class 3). The prevalence of Class 1 was 48-52 % across the three surveys while Class 3 prevalence increased significantly from 13 % in the Dec-2013 survey to 20 % in the Feb-2014 survey. Compared with Class 1, Class 3 were more likely to be female, older, better educated, married, perceive higher susceptibility to H7N9, attribute greater severity to H7N9, report higher current worry, and anticipated worry about H7N9 infection. The three classes reflect different levels of adoption of protection and thereby may have different levels of vulnerability toward contracting H7N9 infection. It appears that as the epidemic intensifies, Class 2 (Good hygiene compliance) members are likely to transfer to Class 3 (Vigilance) while Class 1 (Moderate hygiene compliance) could be unchanged. The young, mostly single males and those with lower educational achievement represent a group for whom public health messages need to be targeted.International Journal of Behavioral Medicine 01/2015; DOI:10.1007/s12529-015-9465-3 · 2.63 Impact Factor
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ABSTRACT: Heavy drinking is common during transitions from high school to college. Optimal programs for diminishing risks for high alcohol consumption often tailor the approach to the specific needs of students. This study describes the results of an Internet-based prevention protocol that tailors the information to the risk associated with a pre-existing phenotype, the Low level of Response (Low LR) to alcohol. Using stratified random assignment, 454 freshmen with Low and High LR values were assigned to 2 education groups (LR-based where all examples were given the context of the Low LR model of heavy drinking or a State Of The Art (SOTA) Group where the same lessons were taught but without an emphasis on LR) or a no-intervention Control Group. Individuals in the 2 education groups viewed 50-minute online videos once per week for 4 weeks. Changes in drinking patterns were assessed at Baseline, 4 weeks, and 8 weeks using a 2 (LR status) by 3 (education group) by 3 (time points) analysis of variance, with additional tests for ethnicity and sex. Low LR participants tended to decrease their usual (p < 0.06) and maximum (p < 0.05) drinks per occasion most prominently when assigned to the LR-based protocol, while those with High LRs improved more in the SOTA Group. The most robust differences were seen when controlling for ethnicity. The effect sizes were small to medium. These results support the advantages of carrying out prevention via the Internet and in tailoring the approach to a pre-existing phenotype. Copyright © 2015 by the Research Society on Alcoholism.Alcoholism Clinical and Experimental Research 02/2015; 39(2). DOI:10.1111/acer.12620 · 3.31 Impact Factor