Cognitive Training to Reduce Impulsivity in HIV-infected Cocaine Users
Phase: NA
Conditions: Cocaine Use Disorders, HIV
Sponsor: Duke University

COGNITIVE TRAINING TO REDUCE IMPULSIVITY IN HIV-INFECTED COCAINE USERS 
 
 
NCT02909101 
 
 
 
 
Study Protocol with Statistical Analysis Plan 
 
 
VERSION DATE: April 13, 2018 
 
 
 
 

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Specific Aims 
This study tests the feasibility and preliminary efficacy of a computerized cognitive training 
program to improve working memory and decrease impulsivity (delay discounting) among HIV-
infected individuals. The specific aims are to 
(1) Investigate the effects of the cognitive training intervention on working memory (primary 
outcome) and delay discounting (secondary outcome) in HIV-infected persons;  
(2) Establish the acceptability of computerized cognitive training among HIV-infected past or 
present cocaine users; and  
(3) Examine the effect of cognitive training on HIV risk behaviors, including cocaine use, 
risky sex, and medication adherence (exploratory outcomes). 
We hypothesize that: (1) Participants assigned to active cognitive training (ACT), compared to 
those in the attention-matched control group (CON), will have greater improvements in working 
memory and reductions in delay discounting; (2) Participants assigned to ACT, compared to 
those in CON, will have greater reductions in HIV risk behaviors, including improvements in 
medication adherence.  
Study design 
The proposed study will test the efficacy of a cognitive training program to improve working 
memory in a sample of HIV-infected cocaine users. We will evaluate the effects of this cognitive 
training intervention on working memory, delay discounting, and HIV risk behaviors. We will first 
screen participants for eligibility. Eligible participants will be assigned to one of two groups (ACT 
or CON) and will complete 48 training sessions over 10 weeks. Participants assigned to ACT 
will complete computerized games designed to enhance working memory, while those assigned 
to the attention-matched CON will complete games that use other brain attributes. We will be 
using a web-based program, Lumosity (Lumos Labs, Inc.; http://www.lumosity.com). Lumosity is 
available to the public and offers user-friendly cognitive training games targeting different brain 
areas. We have developed a contract with Lumosity tailoring the website to fit our study’s 
needs. All participants will complete assessments at baseline, post-training, and 1-month follow-
up to evaluate the impact of the training program. Staff members conducting assessments will 
be blinded to treatment condition in order to ensure no biases occur during testing. 
Eligibility criteria 
The sample will be open to HIV-infected men and women aged 18-60 years of all 
racial/ethnic groups who are currently on antiretroviral medications for >3 months and are 
cocaine users. Cocaine use will be defined as lifetime regular crack/cocaine use lasting >1 year, 
cocaine-type stimulant use disorder, and cocaine as the principal substance of abuse. Exclusion 
criteria will include pregnancy; English non-fluency or illiteracy; ≤ 8th grade education; serious 
and unstable neurological disorders; unstable serious mental illness or acute psychiatric 
distress; and impaired mental status. Women who are pregnant will be excluded because of the 
known effects of pregnancy on neuropsychological functioning (including deficits in memory and 
executive control). To reduce potential attrition, individuals who state they are planning to move 
away from the area within the next 3 months and individuals without stable housing will be 
excluded.   
Recruitment 
Both clinic- and community-based recruitment strategies will be used. Participants will learn 
about the study via flyers in clinics, community-based organizations that serve HIV-positive 
individuals, and participant referrals. Clinic recruitment will occur at local infectious diseases 
clinics. Patients may also self-refer in response to flyers and brochures displayed in the waiting 

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area and exam rooms. We may also run advertisements in local newspapers and online. Finally, 
participants may be recruited through our lab’s repository contact database (IRB Pro00047043).  
Prescreening  
Regardless of how potential participants are informed of the study, interested individuals will 
complete a pre-screening with a member of the research staff to determine preliminary 
eligibility. This pre-screening will occur in person or over the telephone.  
Cognitive Training Study 
Screening Visit. If potentially 
eligible after prescreening, 
participants will be invited to 
complete a 2-3 hour screening visit 
in our laboratory to verify eligibility 
criteria. The informed consent 
process will occur at the beginning 
of this visit, followed by a 
breathalyzer to ensure that the 
participant is not acutely intoxicated. 
The initial part of the screening visit 
will include the urine drug testing 
and pregnancy testing if indicated. 
Participants will then complete 
questionnaires and clinical 
interviews to assess HIV and other 
medical history, substance use, and 
mental health (Table 1). Trained 
research assistants will administer clinical interviews and neuropsychological tests of working 
memory. Additional questionnaires will be administered using audio computer-assisted self-
interview (ACASI) technology. The urine toxicology screen will be used to verify self-reports of 
recent use of cannabis, cocaine, stimulants, opioids, and benzodiazepines.  
In-person Interview and Testing. In-person interview and testing (lasting approximately 90 
minutes) will be conducted by trained research personnel. Interviews will assess substance use 
and impairment, psychiatric history, HIV testing, staging and treatment history, medication 
adherence, substance use, sexual behaviors, and psychiatric history.  
ACASI. Questionnaires will be programmed using QDSTM software. The computer will 
display one question at a time, and participants will respond using a mouse. For patients who 
prefer not to read, the computer will read the questions and responses using prerecorded sound 
files. The ACASI will last approximately 30 minutes will include items related to demographics, 
anxiety and depression, HIV symptoms, stimulant craving, and medical history. 
Baseline Assessment. Eligible participants will be invited back on a separate day for a 3-
hour baseline assessment. At the beginning of this visit, participants will complete a 
breathalyzer, urine drug testing and pregnancy testing if indicated. Participants will then 
complete an assessment battery of standardized measures that includes face-to-face 
interviews, questionnaires, decision making tasks, and neuropsychological testing (Table 2).  
Neurocognition. A 60-minute comprehensive neuropsychological battery will assess 
functioning across performance domains and estimates premorbid intellectual functioning. All 
tests have excellent clinical validity with large national norming samples and will be scored 
using standard procedures. 
Table 1. Eligibility Screening Measures 
Construct 
Instrument(s) 
In-person Interview and Testing 
Substance Use & Impairment Addiction Severity Index-LITE 1,2 
Substance Use Disorders 
Structured Clinical Interview for DSM-5 
(SCID-5) Module E 3 
Psychiatric history 
SCID-5 Modules A and B 3 
HIV Testing and Staging 
HIV Cost and Services Utilization Study 4 
Literacy 
Wide Range Achiecement Test-4 Word 
Reading Subtest 5 
ACASI 
Patient Characteristics 
Demographics 
Anxiety/Depression 
Brief Symptom Inventory 6 
HIV Symptoms 
HIV Symptoms Index 7 
PTSD Symptoms 
Post-Traumatic Stress Disorder Checklist-5 8 
Craving 
Stimulant Craving 9 
Medical History 
Veteran’s Aging Cohort Study 10 
Trait Impulsivity 
Barratt Impulsivity Scale Version 11 11 
Sensation Seeking 
Sensation Seeking Survey Version V 12 

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In-person interview. Trained research personnel will conduct interviews lasting 
approximately 30 minutes. The interview will assess HIV medication adherence, substance use, 
and sexual behaviors.  
ACASI. The ACASI will last approximately 40 minutes and will include items related to 
psychiatric symptoms, food insecurity, stimulant craving, quality of life, smoking history, and 
sexual and drug risk. 
Decision making. Several computerized tasks, lasting approximately 30 minutes, will 
assess distinct aspects of decision making. The Game of Dice Task (GDT) assesses decision 
making. In this task, a virtual die is rolled and the participant is asked to select a single number 
or a combination of two, three, or four numbers. If the number rolled on the die equals any of the 
numbers in the participant’s choice, the participant will gain a specified amount of money in a 
fictitious bank. The participant will lose an equivalent amount from the fictitious bank if the 
number rolled is not equal to any of the numbers in their selection. The participant is tasked with 
accumulating as much money as possible in the bank, and each selection is associated with an 
explicit gain/loss of fictitious money. The amount of fictitious money that can be gained/lost 
increases as the probability of the selection occurring decreases. Risky decisions, defined as 
choices that have less than a 50% chance of occurring, and the frequency of alternative 
Table 2. Baseline Measures 
Construct 
Instrument(s) 
In-person Interview 
Medication adherence 
ARV Adherence 13,14 
Sex/drug risk 
Timeline Follow-back for Substance Use and Sexual Behaviors 15 
HIV Risk Behaviors 
HIV Risk Behavior Scale (HRBS) 16 
Neurocognition 
Attention 
Conners Continuous Performance Test 3 (CPT 3) 17  
Executive Function 
Stroop Color and Word Task 18 
Trail Making Test Part B (TMT B) 19 
Learning 
Hopkins Verbal Learning Test-Revised (HVLT-R) Immediate 20 
Brief Visuospatial Memory Test-Revised (BVMT-R) Immediate 21 
Memory 
HVLT-R Delayed 20 
BVMT-R Delayed 21 
Processing Speed 
Trail Making Test Part A (TMT A) 19 
WAIS-IV Coding 22 
Motor 
Grooved Pegboard Test (GPT) 23 
Verbal Fluency 
Controlled Oral Word Association Test (COWAT; FAS and Animals) 24 
Working Memory 
Paced Auditory Serial Addition Test-100 25 
WAIS-IV Letter-Number Sequencing,22 
WAIS-IV Digit Span 22 
Premorbid Functioning 
Wechsler Test of Adult Reading (WTAR) 26 
Decision Making 
Decision Making 
Game of Dice Task 27 
Delay discounting 
Monetary Choice Questionnaire 28 
Abstract reasoning 
Wisconsin Card Sorting Test-64 (WCST) 29 
ACASI 
Psychiatric Symptoms 
Symptom Checklist 90-Revised (SCL-90) 6 
Food Insecurity 
Household Food Insecurity Access Scale 30 
Craving 
Stimulant Craving 9 
Quality of Life 
World Health Organization Quality of Life-BREF (WHOQOL-BREF) 31 
Self-assessment 
Patient’s Assessment of Own Functioning Inventory 32 
Sexual/Drug Risk 
Risk Assessment Battery (RAB) 33 
Nicotine Dependence 
Fagerstrom Test for Nicotine Dependence (FTND) 34 and smoking history 
Stimulant Dependence 
Severity of Dependence Scale (SDS) 35 

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selections will be analyzed. The Monetary-Choice Questionnaire (MCQ) is a delay discounting 
task. Participants make 36 choices between smaller immediate rewards (ranging from $11 to 
$78) and larger delayed rewards (ranging from $25 to $85 and from 7 to 186 days). An 
individual’s point of indifference where the perceived value of a smaller immediate reward is 
equivalent to a larger delayed reward is computed using the following hyperbolic function: 
Vimmediate=  Vdelayed/(1 + kD), in which V is value in dollars, D is delay in days, and k is a free 
parameter that determines the discount rate.  The Wisconsin Card Sorting Test-64 (WCST) is 
used to measure abstract reasoning, concept generation, and perseverative responding. In this 
computerized task, participants sort cards according to one of three principles of class 
membership, including categories completed, perseverative responses, perseverative errors, 
nonperseverative errors, failure to maintain set, and efficiency of learning.  
Cognitive Training Sessions. At the end of the baseline assessment, enrolled participants 
will be randomly assigned to either the experimental (Active Cognitive Training, or ACT) or 
control (or CON) conditions using simple random assignment. Participants will be trained to use 
Lumosity after the baseline assessment. Research staff will provide instructions and guide them 
through the first training session. Participants will then immediately begin completing sessions 
at home the following day. 
Schedule of training sessions. All enrolled participants will be asked to complete 48 
training sessions over 10 weeks. The sessions will last approximately 20-30 minutes and will be 
completed at home or wherever the participant can obtain computer access. If the participant 
has no means of accessing a computer, sessions can be completed in-person in the research 
laboratory. Participants will be encouraged to complete 6 sessions a week, 1 per day, to reach a 
total of 48 by the end of the 10-week period. While each group will complete the same number 
of sessions to control for possible dosage effects, the content of the sessions will vary by study 
group. Each condition will include 8 unique Lumosity games.  
Active Cognitive Training (ACT). Sessions will include games from Lumosity that are 
designated as targeting working memory. One training session will be comprised of a randomly 
generated subset of 4 of the 8 working memory games, each played twice back-to-back.  
Control Training (CON). The sessions will be in the same format as the ACT group, but will 
utilize other Lumosity games that do not target working memory. These games will be the same 
length as the working memory games and participants will complete the same number of 
randomly generated games per session (4 of the 8 games, played twice back-to-back).  
Post-training Assessment. After completing the 48th training session, or at the end of the 
10-week training window, participants will complete a post-training assessment. This 3-hour visit 
will occur within 1 week of the final training session and will consist of a battery identical to the 
baseline assessment. Alternate forms of neuropsychological tests involving memory will be 
used to avoid effects related to repeated testing. Participants will also complete a process 
measure to describe their experiences of the intervention and provide feedback on perceived 
benefits, barriers to completing sessions, and the length, number, and content of sessions. This 
assessment includes open-ended questions and ratings of satisfaction and helpfulness. 
One-month Follow-up Assessment. One month after the post-training assessment, 
participants will complete a follow-up assessment. This 3-hour visit will consist of a battery 
identical to the baseline assessment. Alternate forms of neuropsychological tests involving 
memory will be used to avoid any effects related to repeated testing.   
Human Subjects Protections 
Rationale for participant selection. The purpose of this study is to examine the impact of 
cognitive training on neurocognitive performance, including working memory and delay 

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discounting, on persons with HIV infection and co-occurring cocaine abuse. Therefore, 
participants will be HIV-positive cocaine users. 
Evaluation of benefits, risks, and discomforts. A direct benefit for participants who 
complete the study may be improved cognitive function as a result of the cognitive training 
exercises administered at each session. The risk/benefit ratio for this study is relatively low and 
there are few expected risks associated with participation in this study. All data collection 
procedures are minimally invasive. All procedures will be performed by research personnel who 
are trained in the study procedures to minimize risks, discomforts, and adverse events. We 
expect that the results of this study will inform new treatments for HIV-infected individuals by 
providing empirical support for a low-cost intervention to improve neuropsychological 
functioning. Given the minimal amount of risk associated with participation, coupled with the 
potential scientific gains, we believe that the risk to participants is reasonable. 
The potential risks associated with this study fall into the following two categories: 
confidentiality and emotional distress. 
1. Confidentiality. The following precautions will protect the privacy of participants and 
maintain confidentiality of research data: (1) All staff will be well trained in confidentiality and 
data security procedures. (2) Privacy will be maintained by conducting all study procedures in 
closed and soundproof rooms. (3) Each participant will be assigned a unique study ID number, 
and all data will be de-identified and coded with ID numbers only. The key linking participant 
names and ID numbers will be stored in a separate password protected document on the 
secure server maintained by the Department Psychiatry & Behavioral Science, and only 
essential study staff will have access to it. (4) Data will be securely stored in locked file cabinets 
in locked offices and in password protected documents on password protected computers and 
secure servers. Access to data storage areas and computers will be restricted. (5) Analysis will 
occur on de-identified data only. (6) Data will only be stored for as long as necessary to 
complete the study, and for adherence to university, hospital, and federal regulations. Thus, 
while we acknowledge that a breach of confidentiality is possible, the likelihood is very low.  
In the event that a subject indicates potential harm to self or others during the research 
study, this will need to be addressed appropriately and with sensitivity. Any disclosures will be 
handled within the framework of existing legal mandates, clinical practice, and social norms. 
Consistent with standard clinical practice, when possible, disclosures will be discussed with the 
participant to determine the best management alternatives. This may include notifying family 
members, referring to medical treatment, calling emergency services, or escorting the 
participant to the Emergency Department at Duke Hospital. When required by law, the Police 
Department and/or the Department of Social Services will be notified. Dr. Meade (the PI) and 
Dr. Towe (co-I) are both licensed clinical psychologists with experience managing such cases. 
2. Emotional distress. Some participants may experience discomfort or embarrassment 
related to providing urine samples and answering questions about substance use and other 
personal behaviors. Participants will be informed prior to the assessment that they may choose 
to skip any question or procedure they find uncomfortable. All research staff will be extensively 
trained on study procedures, including the conduct of interviews that elicit personal information, 
and the importance of being sensitive to and respectful of all participants. If distress does occur, 
research staff will be trained on how to identify and manage it, and when to terminate an 
interview. If necessary, the participant will be referred to mental health treatment. It is important 
to note that, as part of the informed consent procedure, all individuals will be notified that if they 
express direct threats of harm to self or others, the study team may exercise the right to arrange 
care or intervention for the individual if the situation is appraised to constitute an emergency. 

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All project staff will be trained to immediately consult with the PI or back-up person in the 
event that any applicant or enrolled participant appears to be experiencing psychological or 
physical distress. Indications of the need for this might include hearing the individual making 
comments or asking questions that suggest cognitive impairment; noting that the individual 
appears to be highly anxious, depressed, or withdrawn; or having a belief that the individual 
may be contemplating harming himself/herself or another person. Responses on select 
questions (such as the suicide assessment on the SCID assessment) that indicate potential risk 
of harm to self or others also require immediate consultation. In the event that cases such as 
this are brought to the PI or back-up person, she will assist the staff member in identifying 
appropriate community resources and will oversee the process of seeking outside assistance for 
this individual. Multiple levels of back-up support for research personnel will be developed. The 
research team includes two licensed clinical psychologists; they will be available to intervene 
and, when necessary, ensure that appropriate services are received. In the event of clinical 
deterioration, assessors may perform an initial risk assessment, but any clinical intervention or 
actions will be conducted by Dr. Meade, Dr. Towe, or a designated back-up person. 
Consent processes and documents.  Prior to the initiation of any clinical research 
procedures, designated research staff will describe the study’s purpose, all procedures, and 
risks/benefits and review the informed consent document with the participant. Participants will 
be provided ample time to read the consent, ask questions, and deliberate their decision. If they 
choose to participate they will then provide written informed consent. Participants will also sign a 
release of information form to allow study staff to review their medical record at any other facility 
where they have obtained HIV and/or other medical care, if applicable. Participants will be given 
copies of these documents. Participants will provide informed written consent for each of the 
two parts of the study. These documents will be stored in locked file cabinets in locked offices 
separate from other data collected in this study.  
Compensation.  Participants will receive compensation for each of the study visits. 
Participants may earn up to $441. Participants will be compensated $50 for the screening visit, 
$75 for the baseline assessment, $65 for the post-training assessment, and $85 for the 1-month 
follow-up. For the 48 training sessions, participants will be compensated $2 for each completed 
session, and will earn a bonus after every 6 sessions. Participants will earn a $5 bonus after 
completing 6, 12, 18, and 24 sessions; a $10 bonus after 30 and 36 sessions; and a $15 bonus 
after 42 and 48 sessions. Total potential earnings for completing all sessions are $166.  
Compensation will be in the form of a reloadable debit card. In addition, we will offer bus 
tokens (worth $2 for round-trip) or parking passes (worth up to $6) to participants who require 
assistance.  
Safety assessment. Our assessment batteries include several measures intended to 
assess for safety, including breathalyzer for alcohol intoxication and mental status exam. 
Adverse events (AEs) will be monitored throughout the study. Each AE will be classified as 
serious or non-serious, and appropriate reporting procedures will be followed. 
Statistical analyses 
Initial analyses will confirm the psychometric properties of the assessments, and scale 
scores will be constructed. Data distributions will be checked to determine if they meet the 
assumptions of the analytic models, and transformations will be performed when necessary to 
improve distributional qualities. Preliminary analyses will compare study groups on demographic 
and other characteristics obtained in the screening and baseline assessments to identify 
possible failures in random assignment, which would be statistically controlled for in subsequent 
analyses. We will also test for any differential attrition across groups at both follow-ups. All 
analyses will be repeated with other substance use added as a covariate.  

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Hypothesis testing (Aim 1). Using an intent-to-treat analysis, we will investigate the 
differential impact of condition (ACT vs. CON) at the post-training assessment by performing a 2 
(Condition) by 2 (Time) general linear model (GLM) analysis on the main outcome measures of 
working memory (mean T-score on the 3-test battery) and delay discounting (natural log k-
value). Time will be a within subjects factor defined by baseline versus post-training 
assessment. The analysis will be repeated, adding the 1-month follow-up in a 2 (Condition) by 3 
(Time) GLM to detect differential effects of the two conditions on outcomes through the follow-
up period. Significant interactions of Condition and Time are predicted. To examine the 
specificity of the cognitive training intervention, we will use the same models to test for group 
differences on performance in other cognitive domains (e.g., verbal fluency, processing speed) 
and other measures of decision making (i.e., contingency learning, risk taking propensity). 
Additional analyses will be restricted to participants who were randomized to ACT. First, we 
will examine predictors of treatment response (moderators) based on sample characteristics. 
We will use linear regression to predict change in the main outcome variables (working memory 
and delay discounting), with potential moderators entered separately as predictors. Second, we 
will use linear regression to evaluate the effect of treatment dosage (number of sessions 
completed) on change in the outcome variables. Finally, if intervention effects are identified on 
main outcomes, we will test whether effects were mediated by performance on the working 
memory training modules using bootstrap analyses.36-38 
Acceptability (Aim 2). We will examine participant ratings of satisfaction with the cognitive 
training intervention, as well as their perception of its benefits and barriers to completing 
sessions. The intervention will be considered acceptable if participant ratings are high (>3.5 on 
a 5-point scale). We will also calculate the average number of sessions completed and 
determine the proportion of participants who successfully completed the intervention (defined as 
completing ≥36 of the 48 total sessions). The intervention will be considered acceptable to the 
target population if ≥80% complete the intervention.  
Exploratory analyses (Aim 3): To investigate the impact of the intervention on risk 
behaviors, we will use the same GLM models described above to test for differences by 
condition on cocaine use (number of days of use), sexual risk (HRBS sex risk score), and 
adherence to ARVs (percent medication adherence).  
Clinical Trials Registration 
This study is registered at http://www.ClinicalTrials.gov (Identifier: NCT: NCT02909101).   
 
 
 

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