Quality of Research
Documents Reviewed
The documents below were reviewed for Quality of Research. The research point of
contact can provide information regarding the studies reviewed and the availability
of additional materials, including those from more recent studies that may have been conducted.
Outcomes
| Outcome 1: Substance use (alcohol, tobacco, inhalants, marijuana, and polydrug) |
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Description of Measures
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Substance use (alcohol, cigarettes, inhalants, and marijuana) was assessed using self-report items from the LifeSkills Training questionnaire. Students were asked about the frequency and amount of substance use. Lifetime smoking, drinking, and marijuana use were assessed with items that asked if the respondent had ever used the substances (yes or no). Frequency of smoking, drinking, and marijuana use was assessed on a scale with responses ranging from "never" to "more than once a day." The amount of cigarette smoking was assessed on a scale with responses ranging from "never" to "more than a pack a day," and the amount of alcohol use was assessed on a scale with responses ranging from "don't drink" to "more than 6 drinks" per occasion. Frequency of getting drunk was assessed on a scale with responses ranging from "don't drink" to "more than once a day."
In addition, a substance use initiation scale/index was constructed by combining three dichotomous items regarding the use of tobacco, alcohol, and marijuana. Students were asked if they had ever "smoked a cigarette," "had a drink of alcohol," or "smoked marijuana." Responses were coded 0 for no and 1 for yes and summed. For each wave of data, responses were corrected for consistency, so that if an individual answered "yes" at any point in time, the subsequent response to the same question was also coded "yes."
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Key Findings
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In one study, junior high schools were assigned to one of three conditions: LST with annual provider training workshops and ongoing consultation, LST with videotaped training and no consultation, or a usual care control group. Follow-up data were collected 6 years after the intervention. This study found a significant decrease in cigarette smoking, alcohol use (drunkenness), and polydrug use (concurrent tobacco, alcohol, and marijuana use) at follow-up for the two groups of students who received LST (all p values < .05). The strongest intervention effects were observed among students exposed to at least 60% of the LST program (operationally defined as the "fidelity sample"). At follow-up, the LST fidelity sample had significantly lower rates than controls on nearly every measure of tobacco, alcohol, marijuana, and polydrug use (all p values < .05).
In another study, middle school students receiving LST were compared with a control group of students who received a program that was normally in place in New York City schools. Results at posttest and 1-year follow-up indicated that students who received LST reported less smoking, less alcohol use, less inhalant use, and less polydrug use relative to those in the control group (p values ranging from < .001 to < .05). The LST group had a 50% smaller proportion of binge drinkers relative to the control group at both the 1- and 2-year follow-up assessments (p < .05 and p < .01, respectively). In addition, among a subsample of youth at high risk for substance use initiation (participants with poor grades and friends who engage in substance use), those who received LST were found to engage in less smoking (p < .01), less drinking (p < .01), less inhalant use (p < .05), and less polydrug use (p < .01) compared with similarly matched controls who did not receive the intervention.
In a third study, 7th-grade students who received LST had a significantly slower rate of increase in substance initiation (tobacco, alcohol, and marijuana) from pretest to posttest and 1-year follow-up compared with students from a minimal contact control condition (p < .01). Five and a half years past baseline (i.e., when the participants were in 12th grade), LST participants reported significantly lower scores on the overall substance use initiation index (p < .01) as well as less cigarette use initiation (p < .05) and less marijuana use initiation (p < .05) relative to controls. When growth over time was examined in the higher risk subsample, the LST group had slower increases in the rates of frequency of marijuana use (p < .01) and monthly and advanced polydrug use (all p values < .01) compared with the control group.
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Studies Measuring Outcome
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Study 1, Study 2, Study 3
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Study Designs
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Experimental
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Quality of Research Rating
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3.9
(0.0-4.0 scale)
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| Outcome 2: Normative beliefs about substance use and substance use refusal skills |
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Description of Measures
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Normative beliefs about substance use and substance use refusal skills were assessed using self-report items from the LifeSkills Training Questionnaire. For normative beliefs, students were asked about the perceived prevalence of drug use among peers and adults, with separate items for specific substances (cigarettes, beer/wine, marijuana, cocaine or other "hard" drugs, and inhalants). Responses were on a 5-point scale ranging from 1 (none) to 5 (all or almost all).
For refusal skills, 10 items from the questionnaire were used. Five items adapted from the Gambrill-Richey Assertion Inventory assessed refusal intentions; students were asked how likely they would be to say no if someone asked them to try a specific substance (tobacco, alcohol, marijuana, inhalants, and cocaine/other drugs). Another five items assessed students' anticipated likelihood of using various refusal strategies (e.g., "tell them not now," "change the subject," "make up an excuse and leave"). For all 10 items, responses were on a 5-point Likert scale ranging from 1 (definitely would) to 5 (definitely would not).
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Key Findings
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In one study, middle school students receiving LST were compared with a control group of students receiving a program that was normally in place in New York City schools. At the 3-month posttest, LST participants reported lower normative expectations than control students for peer smoking and drinking (both p < .05) and for adult smoking (p < .05), drinking (p < .05), cocaine/hard drug use (p < .01), and inhalant use (p < .05). Similarly, at the 1-year follow-up, LST participants reported lower normative expectations than control students for peer smoking (p < .001) and drinking (p < .01) and for adult smoking (p < .01) and drinking (p < .05). LST participants also scored higher than control students on drug refusal skills at 1-year follow-up (p < .05). Significant effects on normative expectations for peer drinking were seen at 2-year follow-up, with LST participants reporting lower normative expectations than controls (p < .05).
Another study found that the rate of decrease in drug refusal skills was significantly slower from pretest to posttest and 1-year follow-up for 7th-grade students who received LST program compared with students from a minimal contact control condition (p < .01).
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Studies Measuring Outcome
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Study 2, Study 3
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Study Designs
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Experimental
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Quality of Research Rating
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3.9
(0.0-4.0 scale)
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| Outcome 3: Violence and delinquency |
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Description of Measures
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Violent and delinquent behaviors were assessed using 20 self-report items from the LifeSkills Training Questionnaire. Items related to verbal and physical aggression were adapted from Elliott, Huizinga, and Menard. Verbal aggression was measured using 7 items asking students the number of times in the past month they committed acts such as name-calling, yelling, cursing, or telling someone off. Mild physical aggression was measured using 3 items asking students the number of times in the past month they had pushed or shoved, tripped, or hit someone. Items related to fighting and delinquent behaviors were adapted from Hawkins and associates. Fighting was measured using 4 items asking students the number of times in the past year they engaged in behaviors such as picking a fight with someone or hitting someone to hurt the person seriously. Delinquency was measured using 6 items asking students the number of times in the past year they committed acts such as destroying others' property, throwing objects at people or cars, or shoplifting.
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Key Findings
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Results of a study among middle school students demonstrated significant reductions in violence and delinquency at 3-month follow-up for LST participants relative to the control group of students who received a standard heath education curriculum (all p values < .05). Stronger effects were found for students who received at least half of the LST program. These effects included decreased verbal aggression (p < .01), physical aggression (p < .01), fighting (p < .001), and delinquency (p < .05).
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Studies Measuring Outcome
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Study 4
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Study Designs
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Experimental
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Quality of Research Rating
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4.0
(0.0-4.0 scale)
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Study Populations
The following populations were identified in the studies reviewed for Quality of
Research.
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Study
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Age
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Gender
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Race/Ethnicity
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Study 1
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13-17 (Adolescent)
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52% Male
48% Female
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91% White
2% Asian
2% Black or African American
2% Hispanic or Latino
2% Race/ethnicity unspecified
1% American Indian or Alaska Native
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Study 2
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13-17 (Adolescent)
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53% Female
47% Male
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61% Black or African American
22% Hispanic or Latino
6% Asian
6% White
5% Race/ethnicity unspecified
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Study 3
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13-17 (Adolescent)
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52% Male
48% Female
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97% White
3% Race/ethnicity unspecified
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Study 4
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13-17 (Adolescent)
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51% Male
49% Female
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39% Black or African American
33% Hispanic or Latino
10% Race/ethnicity unspecified
10% White
6% Asian
2% American Indian or Alaska Native
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Quality of Research Ratings by Criteria (0.0-4.0 scale)
External reviewers independently evaluate the Quality of Research for an intervention's
reported results using six criteria:
For more information about these criteria and the meaning of the ratings, see Quality of Research.
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Outcome
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Reliability
of Measures
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Validity
of Measures
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Fidelity
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Missing
Data/Attrition
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Confounding
Variables
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Data
Analysis
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Overall
Rating
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1: Substance use (alcohol, tobacco, inhalants, marijuana, and polydrug)
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4.0
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4.0
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3.8
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3.9
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4.0
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4.0
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3.9
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2: Normative beliefs about substance use and substance use refusal skills
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4.0
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4.0
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3.7
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3.9
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4.0
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4.0
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3.9
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3: Violence and delinquency
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4.0
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4.0
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3.8
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4.0
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4.0
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4.0
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4.0
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Study Strengths The outcome measures have excellent reliability and validity indicators and are supported by independent research. The investigators considered and controlled for confounding variables through the use of block randomization design and standardized data collections and by establishing baseline equivalence between groups. Sophisticated techniques were used to statistically account for attrition and missing data. Significant efforts were made to measure intervention fidelity, and adherence rates were high in some studies. The data analyses were appropriate for the study designs and types of data collected and support the inferences made about causal relationships.
Study Weaknesses Attrition and adherence rates to fidelity were a minor concern in some studies.
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