Alcohol Screening in an Ethnically Diverse Sample of Adolescents in Primary Care
Phase: NA
Conditions: Alcohol Use, Drug Use
Sponsor: RAND

Clinical Trial registry name and registration number: Alcohol Screening in an Ethnically 
Diverse Sample of Adolescents in Primary Care; NCT01797835 
April 22, 2019 
 
 

Study protocol and analysis plan 
 
This proposal focuses on screening and treatment referral specifically among adolescents.  In the 
proposed study, we will train PC clinicians (e.g., nurses) in four clinics across two states to use the 
new two-question NIAAA screening guide (NIAAA SG)1 to determine the prevalence of at-risk 
alcohol use among an ethnically and racially diverse group of youth age 12-18, and to test the 
feasibility and practicality of this brief screener for predicting subsequent alcohol use, alcohol risk 
and problems among this population. In addition, we will examine how well the NIAAA SG 
questions identify other behavioral health problems, including cigarette and marijuana use, sexual 
risk behavior, delinquency and conduct disorder.  
 
Youth identified as at-risk according to the NIAAA SG will receive a brief motivational 
interviewing (MI) intervention as recommended by the guide.2  
Our specific aims are: 
Aim 1: Use the NIAAA SG1 to screen 2000 ethnically and racially diverse adolescents age 12-18 
in four PC clinics and assess the prevalence of youth who screen positive for at-risk alcohol use in 
this setting. We will compare prevalence across the NIAAA screening guide, and other highly used 
screening measures, such as the Problem Severity Scale (PS) on the PESQ5, the AUDIT6 and the 
CRAFFT.7  
Aim 2a: Compare the NIAAA SG and the PESQ-PS, AUDIT and CRAFFT against a gold standard 
of DSM diagnosis of abuse or dependence to determine each screener’s utility, sensitivity and 
specificity as a predictor of alcohol risk, use, and problems in this population at baseline and at six 
months. 
Aim2b: Compare the NIAAA SG to the PESQ-PS, AUDIT and CRAFFT to determine each 
screener’s utility, sensitivity and specificity as an initial screen for other behavioral health 
problems, including marijuana use, cigarette smoking, sexual risk behavior, delinquency, and 
conduct disorder at baseline and at six months. 
Aim 3a: Use the NIAAA SG to identify youth who are at moderate and high risk. Provide a brief 
MI intervention in the PC setting to  adolescents who screen in at moderate or high risk based on 
the guide and examine whether alcohol use and problems decrease over a one year period for these 
youth compared to youth at moderate or high risk who receive enhanced usual care.  
Aim 3b: Explore whether there is differential effectiveness of the intervention depending upon 
risk level. 
 
Recruitment protocol 
All adolescents who have appointments at the clinic and are between the age of 12 and 18 will be 
screened by clinic staff using the NIAAA screening guide. We expect to screen approximately 
2000 youth. After completion of the screener and their PC appointment, clinic staff will ask youth 
to be part of a study to complete a web-based baseline and six month survey. Those who agree 
will complete additional surveys. Teens must have parental consent if they are under 18 and must 
also assent. Based on our previous experiences in survey studies with youth, we expect 90% of 
youth to agree to complete the surveys. If a teen would like to participate, but the parent is not 
present, we will follow-up with that teen to obtain parental consent and then schedule a time for 
him or her to return to the clinic. At the 6 month follow up we will survey all individuals who were 
screened as high risk (estimated 25%). We will follow-up with a randomly selected 40% of 
individuals screened as low risk (assuming that 75% were low risk); we will therefore follow up 

810 individuals, which still provides us with ample power to test our hypotheses (see Power 
section) and keeps project costs down. Youth who screen in at moderate or high risk on the NIAAA 
SG will be told that they are eligible to participate in additional surveys at three months and 12 
months, and that they have an opportunity to obtain additional information on AOD use if they are 
interested. They will then complete an additional section of the consent/assent form that details 
the additional surveys and randomization to CHAT (our brief motivational interviewing 
intervention) or enhanced usual care (EUC) (if under 18, they must also have parental consent). 
As noted above, all youth will complete a web-based baseline survey on site and a six month follow 
up web survey. Youth who are part of the randomized trial will also complete follow-up web-
based surveys at 3 months and 12 months. Half of the youth will receive the CHAT MI session, 
which is delivered in 15-20 minutes and is reinforced with a 5-10 minute MI booster phone call 
one month later that follows up on information discussed during the session. EUC: Since usual 
care may differ slightly across the sites, similar to other work in this area, we will provide an EUC 
condition for the other youth. EUC will be designed to replicate current practice, which generally 
consists of teens getting screened for AOD use and ‘yes’ responses being queried further and 
followed by some brief discussion (personal communication from clinic directors). EUC 
participants will also be provided with a brochure from our staff, similar to the brochure for the 
MI intervention, and they will be asked to review it. Given the extra burden of the two additional 
surveys and staying to receive EUC or CHAT, we conservatively estimate that of those who are 
eligible for Aim 3, 70% will agree to participate and will have parental consent. 
 
Statistics 
Analyses for Aim 1 are primarily descriptive. We will calculate prevalence scores for each level 
of each of the four measures (NIAAA SG, PESQ-PS, AUDIT, CRAFFT), and calculate confidence 
intervals of those rates of prevalence. We will explore prevalence differences across location, 
gender, age and race/ethnicity using each measure in a logistic regression.  
 
Overview of follow up for Aims 2 and 3 
At the 6 month follow up, we will follow-up with all at-risk youth and 40% of individuals screened 
as low risk and expect 85% to complete the six-month follow up.  
 
Aim 2a: Compare the NIAAA SG and the PESQ-PS, AUDIT and CRAFFT against a gold 
standard of DSM diagnosis of abuse or dependence to determine each screener’s utility, 
sensitivity and specificity as a predictor of alcohol risk, use, and problems in this population 
at baseline and at six months.  
Aim 2a involves comparing four screening tests (NIAAA SG, PESQ-PS, AUDIT, and CRAFFT) 
to the gold standard of the DSM diagnosis using the DISC. For each test we will calculate the 
sensitivity, specificity, positive predictive value and negative predictive value, along with their 
95% confidence intervals for each potential cutoff for each of the tests. We will calculate age and 
gender specific sensitivity and specificity, and compare sensitivity and specificity across age and 
gender. Because of the confounding of race/ethnicity and location we will calculate sensitivity and 
specificity separately for each racial/ethnic group in each location.   
Aim 2b: Compare the NIAAA SG to the PESQ-PS, AUDIT and CRAFFT to determine each 
screener’s utility, sensitivity and specificity as an initial screen for other behavioral health 
problems, including marijuana use, cigarette smoking, sexual risk behavior, delinquency and 
conduct disorder at baseline and at six months. 

For each test we will calculate the sensitivity, specificity, positive predictive value and negative 
predictive value, along with their 95% confidence intervals for each potential cutoff for each of 
the tests. We will determine an appropriate cutoff to maximize specificity (while maintaining 
sensitivity, as is desirable in a screening program). We will calculate odds ratios and their 
confidence interval, and interpret the c-statistic (the area under the ROC curve).  
 
Aim 3a: Examine whether alcohol use and problems decrease over a one year period for the 
youth at moderate or high risk youth who receive CHAT compared to those who receive 
usual care. 
We will examine differences in outcomes between the two groups at 3-, 6-, and 12-months follow-
up. We will also examine rates of change over time using a growth modeling procedure.8 This 
procedure will allow us to examine overall trajectories of differences in cognitions or behaviors, 
We will use appropriate modeling techniques for continuous outcome variables and categorical 
outcome variables. We will employ facilitator as a fixed factor (i.e. dummy coded), as facilitators 
are involved in both CHAT and EUC conditions. Controlling for facilitator also has the effect of 
controlling for location. We will use full information maximum likelihood (FIML) estimation to 
account for attrition.  
 
Aim 3b: Explore whether there is differential effectiveness of the intervention depending 
upon risk level.  
We will also examine heterogeneity of treatment effects, testing the assumption that there are no 
interactions between baseline measures of initial severity and the effectiveness of the intervention. 
We will use a slopes as outcomes model9 within a structural equation modeling framework to 
determine whether there is a relationship between the rate of improvement of an individual and 
their initial severity - essentially this is an interaction between severity and intervention group.  
 
 
 

 
1. 
NIAAA. Alcohol screening and brief intervention for youth: A practioners guide. NIH 
Publication No. 11-7805. Rockville, MD: NIAAA, DHHS and AAP; 2011. 
2. 
NIAAA. Alcohol screening and brief intervention for youth: A practioner's guide. 
Rockville, MD: NIAAA, NIH, DHHS, and American Academy of Pediatrics; 2011. 
3. 
D'Amico EJ, Miles JNV, Stern SA, Meredith LS. Brief motivational interviewing for teens 
at risk of substance use consequences: A randomized pilot study in a primary care clinic. 
J Subst Abuse Treat. 2008;35:53-61.  
4. 
Stern SA, Meredith LS, Gholson J, Gore P, D’Amico EJ. Project CHAT: A brief motivational 
substance abuse intervention for teens in primary care. J Subst Abuse Treat. 
2007;32(153-165).  
5. 
Winters KC. Development of an adolescent alcohol and other drug abuse screening 
scale: Personal Experience Screening Questionnaire. Addict Behav. 1992;17:479–490.  
6. 
Babor TF, de la Fuente JR, Saunders J, Grant MA. AUDIT: The Alcohol Use Disorders 
Identification Test: Guidelines for use in primary health care. Geneva, Switzerland: World 
Health Organization; 1992. 
7. 
Knight JR, Sherritt L, Shrier LA, Harris SK, Chang G. Validity of the CRAFFT substance 
abuse screening test among adolescent clinic patients. Archives of Pediatric Adolescent 
Medicine. 2002;156(6):607-614.  
8. 
Singer JD, Willett JB. Applied longitudinal data analysis: Modeling change and event 
occurrence. New York: Oxford University Press; 2002. 
9. 
Bollen KA, Curran PJ. Latent curve models: a structural equation perspective. New York: 
Wiley; 2006.