Biomedical subjects

J W Graham

Publications and source records attributed to J W Graham.

At least 19 recordsLinked to original sources

PubMed2004

Preventing alcohol-related harm in college students: Alcohol-related Harm Prevention program effects on hypothesized mediating variables.

The Alcohol-related Harm Prevention (AHP) program is a normative education and skill-acquisition program designed to reduce serious, long-term alcohol-related harm in college students. Without admonishing students not to drink, which is likely to fail in many student populations, the AHP program attempts to give students the necessary perceptions, motivation and skills to intervene within their peer group, and to make proactive harm-avoidance plans with friends prior to social occasions that involve using alcohol. The AHP program is a two-session, in-class intervention that corrects misperceived norms regarding levels of alcohol use, caring about friends, acceptability of risky behaviors and willingness to intervene. The program also makes use of interactive discussions with students and a graded, peer interview assignment to identify and promote harm-prevention strategies. The AHP program was implemented during fall 1999 at a large northeastern university. The program was received very well by students and showed significant effects on the proximal outcomes hypothesized to mediate more distal health-relevant outcomes.

Alcoholism↗

PubMed2003

MRI and the brain in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) can affect any part of the central nervous system (CNS) from the cerebrum to the cauda eqina, giving rise to diverse neurological mainfestations. Despite clinically apparent symptoms and signs, imaging will commonly be normal while at times the magnitude of changes demonstrated on MRI may be out of proportion to the clinical presentation. We describe the MRI techniques used in CNS imaging and the pattern of presentation in SLE.

Brain↗

PubMed2001

Childhood risk factors for persistence of violence in the transition to adulthood: a social development perspective.

This study examined violent behavior from ages 13 to 21 and identified predictors at age 10. Logistic regression was used to assess predictors of developmental patterns of violence. The sample is from a study of 808 youth interviewed annually from age 10 to 16 years, and again at ages 18 and 21. Over 28% of the youth in the sample reported nonviolence throughout adolescence and into early adulthood. Most youth (55%) engaged in violence in adolescence but desisted from violence in early adulthood, while 16% persisted in violent behavior at age 21. Violence in adolescence was best predicted by male gender, Asian American ethnicity (a protective factor), childhood fighting, early individual characteristics, and early antisocial influences. Adult persistence of violence was best predicted by male gender, early school achievement (which was protective), and early antisocial influences. Early prosocial development was also protective against violence persistence for females. Implications for prevention are discussed.

Adolescent↗

PubMed2000

Verifying drug abuse prevention program effects using reciprocal best friend reports.

Considerable research suggests that social influences-based drug abuse prevention programming has produced the most consistently successful preventive effects. However, a common criticism of this literature is that most prevention intervention studies rely solely on self-reported substance use. The purpose of this study was to assess the effects of normative education, arguably the most successful component of social influence based prevention programs, on alcohol and cigarette consumption using both self- and reciprocal best friend reports of substance use. Analyses of subsamples of data from 11,995 students participating in the Adolescent Alcohol Prevention Trial revealed that normative education significantly delayed the onset of alcohol use across the eighth, ninth, and tenth grades among public school students. A similar but somewhat less robust pattern was found for cigarette use. These results suggest that self-report bias does not account for previous findings and demonstrate rather convincingly that normative education is an effective drug prevention strategy for public school settings.

Adolescent↗

PubMed2000

Modeling prevention program effects on growth in substance use: analysis of five years of data from the Adolescent Alcohol Prevention Trial.

The efficacy of prevention programs is typically determined through analysis of covariance. To date, a growth curve modeling approach is not used extensively in program evaluation. However, for longitudinal data there are several advantages to using this approach as compared to methods comparing means at two time points in a piecemeal fashion. In this study, latent growth curve models were used to evaluate the effect of a program on the average level of drug use, rate of change (growth) of drug use, and acceleration or deceleration in the rate of change of drug use. The study relied on data from the Adolescent Alcohol Prevention Trial, a randomized longitudinal drug use prevention program. The program consists of drug use information, resistance skills training, and normative education components. Data regarding cigarette and alcohol use were collected over a 5-year period, grade 7 to grade 11. Students receiving the normative education program had significantly lower average levels of reported cigarette and alcohol use, lower rates of growth for reported cigarette and alcohol use, and less deceleration of reported levels of cigarette and alcohol use as compared with the control group. Growth curve analysis is a powerful and effective tool with which to model change and program efficacy.

Adolescent↗

PubMed2000

Perceived exposure to peer and adult drinking as predictors of growth in positive alcohol expectancies during adolescence.

This study investigated the effects of change in exposure to peer and adult drinking on changes in positive alcohol expectancies during adolescence. Covariance and mean structure analysis were used to model change in the predictors and in alcohol expectancies in a sample of southern California schoolchildren followed from Grades 5 to 10 (N = 3,580). The sample was gender balanced and was predominantly White (51%) and Hispanic (28%). Exposure to peer drinking and rate of change in exposure to peer and adult drinking were found to predict the rate of change in alcohol expectancies. These effects were particularly strong between Grades 5 and 7, suggesting the need for early intervention aimed to prevent the increase in positive alcohol expectancies.

Adolescent↗

PubMed1997

Exploring the effects of age of alcohol use initiation and psychosocial risk factors on subsequent alcohol misuse.

OBJECTIVE: This study examines whether the age of initiation of alcohol use mediates the effects of other variables that predict alcohol misuse among adolescents and also whether the age of initiation of alcohol use accounts for known gender differences in the severity of alcohol misuse. METHOD: Data were taken from an ethnically diverse sample of 808 (412 male) students who were recruited in grade 5 at age 10-11 and followed prospectively on an annual basis for the next 7 years to age 17-18. State-of-the-art missing data methodology was used to address nonresponse due to noninitiation of alcohol use. Structural equation modeling was used to examine hypotheses for the prediction of alcohol misuse. RESULTS: A younger age of alcohol initiation was strongly related to a higher level of alcohol misuse at age 17-18 and fully mediated the effects of parent drinking, proactive parenting, school bonding, peer alcohol initiation and ethnicity, all measured at age 10-11, and perceived harmfulness of alcohol use, measured at age 10-11 and age 11-12. However, age of alcohol initiation did not fully account for gender differences in the level of alcohol misuse at age 17-18. To further examine the role of gender, interactions between gender and school bonding, and gender and friend's alcohol initiation, were evaluated. However, neither of the interaction terms had direct effects on either age of initiation or level of alcohol-related problems. CONCLUSIONS: Most measured risk factors for alcohol misuse were mediated through age of alcohol initiation. Only gender differences in alcohol misuse at age 17-18 were not mediated by age of alcohol initiation. Variables associated with these differences require further study. The results of this study indicate the importance of prevention strategies to delay the age of initiation of alcohol use.

Adolescent↗

PubMed1996

Role of the self-image and smoker stereotype in smoking onset during early adolescence: a longitudinal study.

The present study utilized a longitudinal design to assess whether self-consistency or self-enhancement motives are predictive of future smoking onset. Participants were 1,222 nonsmoking 5th through 8th graders who were followed into the next academic year. The results showed that teens who were above the median in similarity between their self-image and smoker stereotype on coolness, sociability, and intelligence were almost twice as likely to show smoking onset at the 2nd measurement. This is supportive of a self-consistency motive for adolescent smoking. The results of this study provide an important extension to previous cross-sectional research in this area.

Adolescent↗

PubMed1995

Resistance-skills training and onset of alcohol use: evidence for beneficial and potentially harmful effects in public schools and in private Catholic schools.

Recent research suggests that the success of social influence prevention programs is due to enhancing an adolescent's ability to resist passive social pressure (e.g., social modeling and overestimation of peer use), and is not due to teaching refusal skills for combating active social pressure (i.e., alcohol and drug offers). Using 4 waves of longitudinal data (collected in the 5th, 6th, 7th, and 8th grades) from 11,995 students participating in the Adolescent Alcohol Prevention Trial, resistance-skills training was found to be an effective strategy for preventing the onset of alcohol use when program assumptions were met. However, a counterproductive effect was found for adolescents attending public school who received a resistance training only condition.

Adolescent↗

PubMed1995

Changes in the relationship between child support payments and educational attainment of offspring, 1979-1988.

We examine changes over the 1980s in the effect of child support payments on the educational attainment of children age 16 to 19 in the United States, and why child support has a stronger impact than other sources of income. We use 1979 and 1988 Current Population Survey data, covering a period when improvements in enforcement should have increased the proportion of reluctant fathers paying support. We hypothesize and find that the positive effect of child support on education diminished somewhat over this period, both absolutely and in relation to other income.

Adolescent↗

PubMed1994

Testing the generalizability of intervening mechanism theories: understanding the effects of adolescent drug use prevention interventions.

Outcome research has shown that drug prevention programs based on theories of social influence often prevent the onset of adolescent drug use. However, little is known empirically about the processes through which they have their effects. The purpose of the present study was to evaluate intervening mechanism theories of two program models for preventing the onset of adolescent drug use. Analyses based on a total of 3077 fifth graders participating in the Adolescent Alcohol Prevention Trial revealed that both normative education and resistance training activated the causal processes they targeted. While beliefs about prevalence and acceptability significantly mediated the effects of normative education on subsequent adolescent drug use, resistance skills did not significantly predict subsequent drug use. More impressively, this pattern of results was virtually the same across sex, ethnicity, context (public versus private school students), drugs (alcohol, cigarettes, and marijuana) and levels of risk and was durable across time. These findings strongly suggest that successful social influence-based prevention programs may be driven primarily by their ability to foster social norms that reduce an adolescent's social motivation to begin using alcohol, cigarettes, and marijuana.

Adolescent↗

PubMed1994

Peer influence on smoking initiation during early adolescence: a comparison of group members and group outsiders.

In this study, the authors compared group members' and group outsiders' susceptibility to the influence of their friends' smoking. Ss were nonsmokers in Grade 7 who were observed for 1 year. Consistent with their hypothesis, the authors found that group outsiders (Ss who did not have reciprocal friends) were affected more by the smoking of their best friend and by the overall level of smoking among their friends than group members were. Furthermore, this peer influence was strongest for teens who were very concerned about their friends' reactions to their substance use. In addition, consistency in smoking status was related to the formation, but not the breakdown, of reciprocal friendships. Results indicated that teenagers may view smoking as a vehicle for entering a desired friendship group. The authors suggest ways that prevention programs might address this mechanism for adolescent smoking initiation.

Adolescent↗

PubMed1994

Analysis with missing data in drug prevention research.

Missing data problems have been a thorn in the side of prevention researchers for years. Although some solutions for these problems have been available in the statistical literature, these solutions have not found their way into mainstream prevention research. This chapter is meant to serve as an introduction to the systematic application of the missing data analysis solutions presented recently by Little and Rubin (1987) and others. The chapter does not describe a complete strategy, but it is relevant for (1) missing data analysis with continuous (but not categorical) data, (2) data that are reasonably normally distributed, and (3) solutions for missing data problems for analyses related to the general linear model in particular, analyses that use (or can use) a covariance matrix as input. The examples in the chapter come from drug prevention research. The chapter discusses (1) the problem of wanting to ask respondents more questions than most individuals can answer; (2) the problem of attrition and some solutions; and (3) the problem of special measurement procedures that are too expensive or time consuming to obtain for all subjects. The authors end with several conclusions: Whenever possible, researchers should use the Expectation-Maximization (EM) algorithm (or other maximum likelihood procedure, including the multiple-group structural equation-modeling procedure or, where appropriate, multiple imputation, for analyses involving missing data [the chapter provides concrete examples]); If researchers must use other analyses, they should keep in mind that these others produce biased results and should not be relied upon for final analyses; When data are missing, the appropriate missing data analysis procedures do not generate something out of nothing but do make the most out of the data available; When data are missing, researchers should work hard (especially when planning a study) to find the cause of missingness and include the cause in the analysis models; and Researchers should sample the cases originally missing (whenever possible) and adjust EM algorithm parameter estimates accordingly.

Algorithms↗

PubMed1994

Latent transition analysis and how it can address prevention research questions.

The objective of this chapter is to introduce latent transition analysis (LTA) to the substance use prevention research community. LTA is a new methodological technique for testing stage-sequential models, such as models of substance use onset. LTA estimates several different sets of parameters. One of these sets is the transition probability matrix, which contains information about the probability of movement between stages in the model. LTA can be used to evaluate the effectiveness of prevention intervention programs by comparing the transition probability matrices of the program and control groups. If the prevention program is successful, the transition probability matrices will indicate that the probability of moving to a more advanced stage of drug use is lower for the program participants than for the control group. An advantage of taking a stage-sequential approach is that examining the transition probability matrix reveals how effective a program is for individuals entering the program with different levels and types of substance use experience. In this chapter, LTA is used to evaluate a variety of models of the early onset process separately for Anglo, Latino, and Asian-American adolescents, measured in seventh grade and again in eighth grade. Although somewhat different models are found to fit the three ethnic groups best, the differences likely are due to differences in the overall amount of substance use experience. Based on these results, it is suggested that, to be most effective, prevention programs should take place earlier for Anglos and Latinos, and later, followed by boosters, for Asian Americans.

Alcohol Drinking↗

PubMed1993

Diffusion of a school-based substance abuse prevention program: predictors of program implementation.

BACKGROUND: The present study addresses diffusion of a psychosocial-based substance abuse prevention program, including: (a) teacher adoption, implementation, and maintenance; (b) teacher characteristics associated with implementation; (c) the relationship between integrity of program delivery and program outcomes; and (d) the effectiveness of teacher training and school principal involvement in increasing implementation. METHODS: Participants were teachers (n = 60), school principals (n = 25), and fifth-grade students (n = 1147) from four Los Angeles area school districts. Districts were randomly assigned to an intensive or brief teacher training condition. Schools were randomly assigned to a principal-intervention or a no-principal-intervention condition. Assessments included teacher and principal self-reports, classroom observations of program delivery, and evaluation of immediate program outcomes. RESULTS: During the first year, 78% of trained teachers implemented one or more program lessons. During the second year, only 25% maintained implementation of the program. Implementors reported fewer years of teaching experience and stronger self-efficacy, enthusiasm, preparedness, teaching methods compatibility, and principal encouragement than did nonimplementors. The principal intervention increased rates of implementation, but the intensive teacher training did not. Integrity of program delivery was positively associated with immediate program outcomes. CONCLUSIONS: Program implementation was highly variable, suggesting that widespread teacher use of psychosocial-based programs cannot be taken for granted. Strategies for increasing implementation and maintenance need to be developed.

Alcoholism↗

PubMed1993

Evaluating interventions with differential attrition: the importance of nonresponse mechanisms and use of follow-up data.

Evaluations of psychological interventions are often criticized because of differential attrition, which is cited as a severe threat to validity. The present study shows that differential attrition is not a problem unless the mechanism causing the attrition is inaccessible (unavailable for analysis). With a simulation study, we show that conclusions about program effects (a) are unbiased when there is no differential attrition, even with usual complete cases analysis; (b) may be severely biased when based on usual complete cases analyses and there is differential attrition; (c) are unbiased when based on the expectation-maximization (EM) algorithm, even when there is differential attrition, as long as the attrition mechanism is accessible; and (d) are biased, even with the EM algorithm, when the attrition mechanism is inaccessible. Following Little and Rubin (1987), we advocate the collection of new data from a random sample of subjects with initially missing data. On the basis of these data, we propose a simple correction to the EM algorithm estimates. In our study, the correction produced unbiased estimates of program effects parameters, even with an inaccessible attrition mechanism and substantial differential attrition.

Bias↗

PubMed1991

Preventing alcohol, marijuana, and cigarette use among adolescents: peer pressure resistance training versus establishing conservative norms.

BACKGROUND: Two strategies for preventing the onset of alcohol abuse, and marijuana and cigarette use were tested in junior high schools in Los Angeles and Orange Counties, California. The first strategy taught skills to refuse substance use offers. The second strategy corrected erroneous normative perceptions about prevalence and acceptability of use among peers and established conservative groups norms regarding use. METHODS: Four experimental conditions were created by randomly assigning schools to receive (a) neither of the experimental curricula (placebo comparison), (b) resistance skill training alone, (c) normative education alone, or (d) both resistance skill training and normative education. Students were pretested prior to the program and post-tested 1 year following delivery of the program. RESULTS: There were main effects of normative education for summary measures of alcohol (P = 0.0011), marijuana (P = 0.0096), and cigarette smoking (P = 0.0311). All individual dichotomous measures of alcohol, marijuana, and tobacco use indicated significant reductions in onset attributable to normative education. There were no significant main effects of resistance skill training. CONCLUSION: These results suggest that establishing conservative norms is an effective strategy for preventing substance use.

Adolescent↗

PubMed1991

Modeling transitions in latent stage-sequential processes: a substance use prevention example.

This article illustrates the use of latent transition analysis (LTA), a methodology for testing stage-sequential models of individual growth. LTA is an outgrowth of latent class theory and is a particular type of latent Markov model emphasizing the use of multiple manifest indicators. LTA is used to compare the fit of two models of early adolescent substance use onset and to assess the effects of a school-based substance use prevention program on Ss measured in 7th grade and again in 8th grade. Several interesting findings emerged. First, a model of substance use onset including both alcohol and tobacco use as possible starting points fit better than a model that included alcohol use as the only starting point. Second, Ss who had tried tobacco but not alcohol in in 7th grade seemed to be on an accelerated onset trajectory. Third, the normative education prevention program was generally successful, except for the students who had tried only tobacco in 7th grade.

Age Factors↗