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Biomedical subjects

D Ary

Publications and source records attributed to D Ary.

17 recordsLinked to original sources
PubMed2000

The value of interrupted time-series experiments for community intervention research.

Greater use of interrupted time-series experiments is advocated for community intervention research. Time-series designs enable the development of knowledge about the effects of community interventions and policies in circumstances in which randomized controlled trials are too expensive, premature, or simply impractical. The multiple baseline time-series design typically involves two or more communities that are repeatedly assessed, with the intervention introduced into one community at a time. It is particularly well suited to initial evaluations of community interventions and the refinement of those interventions. This paper describes the main features of multiple baseline designs and related repeated-measures time-series experiments, discusses the threats to internal validity in multiple baseline designs, and outlines techniques for statistical analyses of time-series data. Examples are given of the use of multiple baseline designs in evaluating community interventions and policy changes.

Community Health Services↗
PubMed1998

Contributions of the social context to the development of adolescent substance use: a multivariate latent growth modeling approach.

This article demonstrates a latent growth curve methodology for analyzing longitudinal data of adolescent substance use. Hypotheses concerning the form of growth in alcohol, cigarette, and marijuana use, and covariates influencing the form of growth, were tested. Participants were male and female adolescents (n = 664) assessed at three time points. A common trajectory existed across the developmental period with significant increases in all three substances. Second-order multivariate extensions of the basic latent growth modeling framework suggested that associations among the individual differences parameters, representing growth or change in the various substance use behaviors, could be adequately modeled by a higher-order substance use construct. Inept parental monitoring, parent-child conflict, peer deviance, academic failure, gender, and age, were significant predictors of initial levels and the trajectory of substance use.

Achievement↗
PubMed1997

Development and evaluation of a sexual decision-making and social skills program: "the choice is yours--preventing HIV/STDs".

A series of interactive videodisc programs designed to reduce HIV/STD risk behaviors was developed and evaluated. Separate programs were developed for each of three race/ethnicities (African American, Hispanic, and Caucasian) at each of two age levels (middle school and high school) using extensive formative procedures. Each program uses scenarios with extensive branching story lines to teach decision-making skills and socially appropriate responses to potentially risky sexual situations. In a randomized experiment with 827 students, significant changes were observed at posttest for the four constructs assessed: (1) belief that sex occurs as a result of decisions (vs. "it just happens"), (2) belief that even a single incident of unprotected sex can result in an STD or pregnancy, (3) intentions and attitudes toward use of condoms, and (4) self-efficacy in remaining abstinent (i.e., avoiding sex). At 30-day follow-up, three of the four measures remained significant.

Adolescent↗
PubMed1996

Mobilizing positive reinforcement in communities to reduce youth access to tobacco.

A community intervention to mobilize positive reinforcement for not selling tobacco to young people was evaluated. The intervention had five components: (a) mobilization of community support, (b) merchant education, (c) changing consequences to clerks for selling or not selling to those under 18, (d) publicity about clerks' refusals to sell, and (e) feedback to store owners or managers about the extent of their sales to adolescents. A multiple baseline design experiment was conducted, in which two small Oregon communities received the intervention, while two other continued in baseline. Outlets' willingness to sell was assessed repeatedly by teenage volunteers. The intervention significantly reduced the proportion of stores willing to sell. Mobilizing social and material reinforcement for stores not selling tobacco to young people is a viable means of reducing such sales. It may be especially valuable in communities where laws against sales to minors go unenforced.

Adolescent↗
PubMed1996

Experimental evaluation of a modular approach to mobilizing antitobacco influences of peers and parents.

The experimental evaluation of two components of a community intervention to prevent adolescent tobacco use are described. Youth antitobacco activities (e.g., peer quizzes, sidewalk art, poster and T-shirt giveaways, etc.) and family communications activities (pamphlets to parents and student quizzes of parents) were evaluated in two time-series experiments, each of which was conducted in two experimental and one control community. Students in Grades 6 and 8 and their parents were assessed in a series of four phone surveys in the first experiment and six phone surveys in the second. Implementation of the youth antitobacco and family communications activities led to significantly greater exposure of young people to antitobacco information. They led to increases in parent and youth knowledge about tobacco use and more negative attitudes toward tobacco. In Experiment 2, youths in intervention communities had significantly lower rated intentions to smoke. The findings suggest the value of a modular approach to community interventions for influencing the social context relevant to the onset of adolescent tobacco use.

Adolescent↗
PubMed1994

The social context for risky sexual behavior among adolescents.

This study supports a model of adolescents' risky sexual behavior in which this behavior is seen as a product of the same peer and family factors which influence a wide range of problem behaviors. The Patterson et al. (1992) model of peer and parental factors associated with adolescents' sexual risk-taking behavior was tested on three independent samples of adolescents, ages 14 through 18. Adolescents whose peers were reported to engage in diverse problem behaviors were more likely to engage in risky sexual behavior. Poor parental monitoring and parent-child coercive interactions were associated having deviant peers, and poor parental monitoring also had a direct relationship to risky sexual behavior. Family involvement was associated with fewer parent-child coercive interactions. Less availability of parental figures in the family was directly associated with risky sexual behavior and was also associated with poorer parental monitoring.

Adolescent↗
PubMed1991

Subject attrition in prevention research.

Subject attrition threatens the internal validity of substance abuse prevention studies because differences in the rate of attrition and the substance use behavior of remaining subjects in the different conditions could account for any differences found in substance use rates. Attrition threatens the external validity of prevention studies because, to the extent that study dropouts are different from remaining subjects, the results of the study may not be generalizable to study dropouts. Analysis of these threats to the validity of prevention studies should be routinely conducted. However, studies of alcohol and drug abuse prevention have generally failed to report or analyze subject attrition. Smoking prevention studies have more frequently reported attrition, and they have recently begun to analyze the degree to which attrition may affect the internal and external validity of the study. Evidence thus far suggests that differences in attrition across conditions do occur occasionally. The evidence is substantial that study dropouts are systematically more likely to smoke, to use other substances, and to score highly on other risk-taking measures.

Alcoholism↗
PubMed1990

Social and behavioral factors associated with high-risk sexual behavior among adolescents.

Relationships among risky sexual behaviors, other problem behaviors, and the family and peer context were examined for two samples of adolescents. Many adolescents reported behaviors (e.g., promiscuity or nonuse of condoms) which risked HIV or other sexually transmitted disease infection. Such risky behaviors were significantly intercorrelated. Consistent condom use was rare among those whose behavior otherwise entailed the greatest risk of infection. In both samples, an index of high-risk sexual behavior was significantly related to antisocial behavior, cigarette smoking, and illicit drug or alcohol use. Social context variables, including family structure, parenting practices, and friends' engagement in problem behaviors, were associated with high-risk sexual behavior. Finally, for sexually active adolescents, problem behaviors and social context variables were predictive of nonuse of condoms. Results were consistent across the two studies and regression weights held up well under cross-validation.

Adolescent↗
PubMed1990

The tobacco use research program at Oregon Research Institute.

The research program at ORI deals with both adolescent and adult tobacco use and is guided by a behavioral framework which emphasizes the role of the social context in tobacco use onset, maintenance and cessation. Growing appreciation of the importance of social context variables, combined with an emerging recognition of the need for a public health rather than clinical perspective on tobacco use, have led to a focus on interventions in larger social systems such as schools, worksites, health care plans, and communities. This research requires attention to the science of behavior change at both the individual and organizational levels.

Adolescent↗
PubMed1990

Parent-adolescent problem-solving interactions and drug use.

This study reports on the social problem-solving interactions of young adolescents in single-parent and intact families on substance-specific and nonsubstance-related issues. Although research has shown the impact of families on adolescent substance use, all of the previous results have been based on questionnaire or interview data. A sample of 128 families was selected from a larger sample of 763 within a longitudinal study of adolescent substance use. Parent(s) and one adolescent, aged 11-15, participated in interactions which were videotaped for later coding. In three standard scenarios, the families discussed fictional assignments from a health class teacher about the use of cigarettes, alcohol, and marijuana. In addition, they discussed an issue salient to them that was the source of recent conflict. Results showed that aversive affective behavior was more likely to be displayed by substance-using adolescents, whether or not the issue was drug-related. Mothers' and fathers' alcohol use was also shown to contribute to alcohol and cigarette use among their children, while fathers' smoking contributed to marijuana and hard drug use. These data suggest that such families may not be skilled at resolving issues and coping with life's difficulties whether or not they are drug-related.

Adolescent↗
PubMed1987

Do smoking prevention programs really work? Attrition and the internal and external validity of an evaluation of a refusal skills training program.

This study investigated the effects of a smoking prevention program that emphasized refusal skills training on 1730 adolescents in three high schools and six middle schools. Classes within these schools were randomly assigned to treatment or no-treatment conditions to avoid confounding schools with treatment condition. The effects of attrition on the internal and external validity of the study were examined. Although the results indicated an apparent effect of the program at the 1-year follow-up in deterring continued smoking among those who were smoking at pretest, this result may have been due to a higher rate of attrition among high-rate smokers in the treatment condition than in the control condition. Attrition also affected external validity. Across both conditions, subjects who were smoking at pretest and who were at risk to smoke were more likely to be missing at follow-up. The program did have an effect on the refusal skills of participants and the validity of this effect was not jeopardized by differential attrition.

Adolescent↗
PubMed1987

How generalizable are the effects of smoking prevention programs? Refusal skills training and parent messages in a teacher-administered program.

This study investigated both substantive and methodological issues associated with school-based smoking prevention programs. Substantive issues included the efficacy of a refusal skills training curriculum and of parent messages mailed to students' homes. Methodological issues included the effects of assigning classrooms versus entire schools to experimental conditions and determination of the effects of attrition on internal and external validity. Results revealed differential impact for different subgroups of adolescents. The refusal skills program produced lower rates of smoking than the control condition for students who were smokers at the pretreatment assessment but may have produced detrimental effects among males who were nonsmokers at pretest. The provision of parent messages did not affect outcome. Method of assignment (schools versus classrooms) failed to produce significant effects, and attrition did not affect internal validity. However, the above differential findings, as well as the impact of attrition on external validity, raise questions concerning the generalizability of smoking prevention programs.

Adolescent↗
PubMed1986

Scholarly productivity in mental retardation.

The most productive institutions in social, educational, and psychological research in mental retardation were identified by noting the affiliations of authors who have published recently in the field. A frequency count was made of the studies published, giving credit to universities on the basis of the percentage of the total contribution provided by particular investigators, up to a maximum of one full publication. Also, the number of publications represented by each particular university was computed. The implications of these particular data are briefly discussed.

Efficiency↗
PubMed1985

Expired air carbon monoxide and saliva thiocyanate: relationships to self-reports of marijuana and cigarette smoking.

This study examined the relationship between self-reports of marijuana and cigarette smoking, and the physiological measures of expired air carbon monoxide (CO) and saliva thiocyanate (SCN) in a sample of 1,130 seventh, ninth, tenth, eleventh, and twelfth graders. Subjects who reported marijuana smoking were likely to also report cigarette smoking. The correlation between self-reported marijuana smoking and SCN was negligible. The correlation between CO and self-reported marijuana smoking was statistically significant, but when the variance due to cigarette smoking was removed, this relationship also became negligible. The existence of a sizeable number of marijuana smokers in this sample of adolescents did not alter the correlation between CO and self-reports of cigarette smoking. However, in adult samples, where marijuana and cigarette smoking are less highly correlated, marijuana smoking could affect the relationship between CO and self-reported cigarette smoking. Carbon monoxide predicted self-reported cigarette smoking better than did saliva thiocyanate. There was an interaction between grade and the CO/cigarette smoking correlation. The correlations were generally higher in upper grades.

Adolescent↗
PubMed1984

A situational analysis of adolescent smoking.

Forty-four adolescent smokers self-monitored their smoking for 1 week. Four 4 hr each day subjects recorded the person, place, and activity associated with each cigarette smoked. Seventy-one percent of all cigarettes were smoked in the presence of another person. Roughly half of those cigarettes were were smoked with peers. A surprising amount of smoking occurred in the subject's own home, suggesting that the smoking of the subjects is accepted, if not condoned , by their parents. The data generally confirm the social nature of adolescent smoking.

Adolescent↗
PubMed1983

Peer modeling effects in the smoking behavior of teenagers.

Modeling influences on adolescent smoking behavior were investigated. Twenty-eight male and twenty-eight female teenagers were exposed to each of three experimental conditions: a male smoking confederate, a female smoking confederate, and no model present. The order of each of these half-hour long conditions was counterbalanced across subjects. Three aspects of smoking behavior were directly observed: number of cigarettes smoked, number of puffs per cigarette, and duration of each cigarette. The presence of a smoking model increased the number of people who smoked and the number of cigarettes smoked and decreased the number of puffs per cigarette. The sex of the model did not affect the smoking behavior of either male or female subjects. Boys tended to smoke more cigarettes than girls (p less than .06) and boys took significantly more puffs per cigarette than did girls in the model present conditions. The results provide experimental confirmation that modeling influences teenagers' smoking behavior, but the rate of smoking in the absence of a model demonstrates that modeling effects cannot account for the maintenance of smoking.

Adolescent↗