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| ID | Type | Description | Link |
|---|---|---|---|
| CX001807-01A1 | Other Grant/Funding Number | VA CSR&D |
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The proposed work will investigate changes in brain signaling and cognitive functioning that support recovery from addiction, as well as use of pretreatment neurocognitive functioning to inform substance use treatment planning. Substance use disorders are prevalent amongst Veterans. Cocaine addiction, in particular, has been shown to complicate treatment of other high priority behavioral health problems in the Veteran population (e.g., PTSD, opioid addiction). While there are currently no approved medications to support recovery from cocaine addiction, research indicates that Contingency Management (CM) - a behavioral intervention for cocaine users - can be effective. However, individual responses are variable and long-term benefits are limited. This CDA will test a new model of how CM works by examining brain-based predictors and indicators of treatment response. Results will have immediate implications for measurement-based implementation of existing CM variants within the VA, supporting access to the version of CM that is best aligned with each Veteran's needs.
Electrophysiological methods, including event-related potential and functional connectivity approaches, have potential to clarify mechanisms of substance use treatment response and characterize individual differences therein. Veterans are disproportionately affected by disorders of addiction, of which cocaine use disorder (CUD) is particularly problematic due to high relapse rates and the absence of approved pharmacotherapy options. Behavioral interventions for CUD have therefore become an important focus and Contingency Management (CM) has emerged as the best-supported approach. CM involves reinforcing cocaine abstinence (established through objective testing) with reliable, short-term reward, such as chances to win prizes (i.e., Prize-Based CM or PBCM). Given robust empirical support, nationwide dissemination of PBCM has been supported by a VHA initiative since 2011. However, PBCM response rates are variable and long-term benefits are limited - problems magnified by the cost of implementation with respect to staffing and prizes. Measurement-based approaches to PBCM implementation have promise to improve the effectiveness and efficiency of CM programming but have not yet been investigated within the VA or considered in relation to promising neuromarkers. Importantly, two versions of PBCM are already utilized at VA sites and may differentially benefit individuals with distinct neurocognitive profiles. Specifically, VA PBCM programs employ either abstract (voucher prize) or concrete (tangible prize) incentives, the latter of which may more effectively incentivize abstinence in Veterans with poor future-oriented thinking and planning ability. While selection between existing PBCM variants currently reflects practical considerations only, pretreatment neurocognitive functioning could meaningfully and realistically inform clinical decision-making in this regard.
This project aims to advance measurement-based implementation of CM by testing a novel neurocognitive model with immediate implications for the use of abstract versus concrete PBCM incentives within the VA. Specifically, the future-minded decision-making (FMDM) model posits that CM scaffolds future-oriented goal representation and self-control to support abstinence during in the moment use-related decision-making. For individuals with greater FMDM impairment, concrete, readily-accessible incentives may be more effective than abstract voucher-based rewards (which require future-oriented thinking and planning to acquire value). To test this model, neurocognitive substrates of FMDM will be examined as predictors of differential treatment response in voucher (VoucherPBCM) versus tangible prize (TangiblePBCM) versions of PBCM. Treatment-related change in neural and cognitive-behavioral correlates of FMDM will also be evaluated in PBCM-adherent versus non-adherent subgroups. Veterans with CUD will be allocated to VoucherPBCM or TangiblePBCM conditions and followed for a 12-week treatment interval. Pre- and post-treatment electroencephalography (EEG) and cognitive-behavioral assessments will be used to measure FMDM-related constructs (working memory, self-control, future-oriented decision-making, future reward representation) and related neuromarkers. These measures will be investigated as predictors of differential treatment response in VoucherPBCM versus TangiblePBCM, as well as maintenance of gains during a post-treatment follow-up period. Change in FMDM-related neural and cognitive measures over the course of treatment will also be evaluated for evidence of neuroadaptation (e.g., changes in functional connectivity) and enhancement of FMDM function through PBCM. Taken together, results of the current research project will represent a first step toward precision implementation of CM within the VA.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Tangible Prize-Based Contingency Management (TangiblePBCM) | Experimental | For participants assigned to TangiblePBCM, prize draws resulting in one or more small, large, or jumbo wins will result in access to a prize cabinet stocked with small, medium, large, and jumbo financial incentive items. Medium incentive items are included for selection in the event that a patient draws several small prize slips on the same day and are considered equivalent to 4 small prizes. Selection of specific prize items will be informed by patient preference and items will be restocked at least every 2 weeks. The prize cabinet will be open during TangiblePBCM sessions such that prize items are readily visible. Selection of prizes, maintenance of the prize cabinet, and policies regarding prize redemption will follow published guidance on administration of TangiblePBCM within the context of research protocols. |
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| Voucher Prize-Based Contingency Management (VoucherPBCM) | Experimental | For participants assigned to VoucherPBCM, prize draws resulting in one or more small, large, or jumbo wins will be reinforced with VA Canteen vouchers in the specified incentive range (i.e., small, large, or jumbo). |
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| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Prize-Based Contingency Management | Behavioral | Participants assigned to Prize-based Contingency Management (PBCM) conditions will receive PBCM as an adjunct to TAU. PBCM will involve twice weekly one-on-one sessions with a provider for 12-weeks. During each session, a urine specimen provided by the patient will be tested for cocaine using a point-of-care dip-test. Results of point-of-care testing will be shared with the patient and negative results will be reinforced with draws from a fish bowl containing 500 paper slips, 250 of which award small, large, or jumbo prizes (remaining slips deliver words of encouragement). Patients will be reinforced with a single prize draw for their first negative specimen; an additional prize draw will be added for each consecutive negative result (up to 8 prize draws per session). Abstinence-contingent prize draws will be reset to one upon either a positive test result or unexcused, missed appointment. |
| Measure | Description | Time Frame |
|---|---|---|
| % Cocaine-Negative Urine Specimens Per Participant | Percentage of cocaine-negative urine specimens during the 12-week treatment interval out of the total number possible, computed on a per-participant basis. The denominator was adjusted for participants for whom a full course of treatment could not be delivered due to suspension of face-to-face research activities during the COVID-19 pandemic. Denominators were similarly adjusted for 2 TAU participants who withdrew from the study during the 12-week treatment interval. Descriptive statistics represent the mean and standard deviation of the per-participant percentage of cocaine-negative urine specimens, computed across participants within each arm. | 12-Week Treatment Interval |
| Longest Duration of Cocaine Abstinence (LDCA) | Longest period of objectively-verified abstinence from cocaine during treatment. It is noted that two TAU participants withdrew during the 12-week treatment interval. For these participants, the LDCA was computed for the pre-withdrawal period only. | 12-Week Treatment Interval |
| Measure | Description | Time Frame |
|---|---|---|
| % Contingency Management (CM) Sessions Attended Per Participant (CM Groups Only) | Percentage of CM treatment sessions attended out of the total number possible, computed on a per-participant basis. The denominator was adjusted for participants for whom a full course of treatment could not be delivered due to suspension of face-to-face research activities during the COVID-19 pandemic. Descriptive statistics represent the mean and standard deviation of the per-participant percentage of CM sessions attended, computed across participants within each arm. |
| Measure | Description | Time Frame |
|---|---|---|
| Difference in Control-related Theta Synchronization From Baseline to Post-Treatment | Theta synchronization between anterior cingulate cortex (Cz) and lateral prefrontal cortex (F3, F4, FC5, FC6) was measured to assess differences in functional connectivity between baseline and post-treatment (i.e., follow-up assessment conducted after the conclusion of the 12-week treatment interval) for high versus low conflict events. At each timepoint, phase locking value (PLV) was computed for 4 electrode pairs (Cz-F3, Cz-F4, Cz-FC5, Cz-FC6) across 3 stimulus conditions ranging from low to high conflict (Congruent, Intermediate-Incongruent, High-Incongruent) and for high-conflict error versus low-conflict correct responses in the Parametric Conflict Flankers task. A wavelet transformation isolated theta activity, and PLV was derived from normalized complex wavelet phases. PLV quantifies trial-to-trial phase synchrony (0-1), with 1 representing perfect synchrony. Descriptive data reported below represent the average PLV across the 4 electrode pairs. |
Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Sarah E. Forster, PhD | VA Pittsburgh Healthcare System University Drive Division, Pittsburgh, PA | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| VA Pittsburgh Healthcare System University Drive Division, Pittsburgh, PA | Pittsburgh | Pennsylvania | 15240 | United States |
If possible, a de-identified, anonymized dataset will be created and shared. However, specific arrangements for sharing have not yet been made and options for data sharing (for example, the availability of data repositories for electroencephalographic data files), as well as VA policies regarding data sharing may change over the course of the study. A detailed plan for data sharing will be developed and approved upon completion of data collection.
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Before randomization, participants completed a pre-screening interview. Those eligible were invited to enroll and proceed to full screening. Participants subsequently completed a baseline assessment visit that included biospecimen testing, interviews, questionnaires, cognitive-behavioral tasks, and an electroencephalography (EEG) session. Of the 122 unique Veterans prescreened, 63 met initial eligibility criteria and were enrolled in the study, with 45 subsequently proceeding to randomization.
Recruitment took place through the VA Pittsburgh Healthcare System and other local sites serving Veterans with Substance Use Disorders. Methods included mailings, provider referrals, public advertisements, event info tables, EHR screening, and announcements during therapy groups. Recruitment began in November 2019 but was paused due to COVID-19 from March 17, 2020, to January 15, 2021. It resumed thereafter and continued until enrollment ended on August 31, 2023.
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| ID | Title | Description |
|---|---|---|
| FG000 | Tangible Prize-Based Contingency Management (TangiblePBCM) | Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to TangiblePBCM, prizes are awarded in the form of tangible items, which are chosen from a physical "prize cabinet." Participants may redeem their draws for small, medium, large, or jumbo prizes, with medium prizes valued at approximately 5 small prizes. The cabinet is visible during sessions and restocked regularly, and the selection of prizes is guided by patient preference. All participants continue to receive their usual outpatient treatment and medications alongside PBCM. |
| FG001 | Voucher Prize-Based Contingency Management (VoucherPBCM) | Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to VoucherPBCM, prize draws resulting in small, large, or jumbo wins are rewarded with VA Canteen vouchers of corresponding value. These vouchers can be redeemed at Veterans Canteen Service vendors, including the hospital cafeteria and Patriot Store. |
| FG002 | Treatment As Usual (TAU) | A treatment-as-usual (TAU) arm was originally included in the study design but was discontinued early in the trial due to evidence that its inclusion adversely affected participant accrual and retention among treatment-seeking individuals with cocaine use disorder. Participants randomized to TAU received standard care without the addition of prize-based contingency management (PBCM). Although they were still required to submit urine samples twice weekly for testing, they did not receive therapeutic incentives based on their urinalysis results. |
| Title | Milestones | Reasons Not Completed | |||||||||||||||||||||
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| 12-Week Treatment Interval |
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| Post-Tx Evaluation Session |
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| 6-Month Post-Tx Follow-Up Period |
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| ID | Title | Description |
|---|---|---|
| BG000 | Tangible Prize-Based Contingency Management (TangiblePBCM) | Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to TangiblePBCM, prizes are awarded in the form of tangible items, which are chosen from a physical "prize cabinet." Participants may redeem their draws for small, medium, large, or jumbo prizes, with medium prizes valued at approximately 5 small prizes. The cabinet is visible during sessions and restocked regularly, and the selection of prizes is guided by patient preference. All participants continue to receive their usual outpatient treatment and medications alongside PBCM. |
| Units | Counts |
|---|---|
| Participants |
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| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | Mean |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | % Cocaine-Negative Urine Specimens Per Participant | Percentage of cocaine-negative urine specimens during the 12-week treatment interval out of the total number possible, computed on a per-participant basis. The denominator was adjusted for participants for whom a full course of treatment could not be delivered due to suspension of face-to-face research activities during the COVID-19 pandemic. Denominators were similarly adjusted for 2 TAU participants who withdrew from the study during the 12-week treatment interval. Descriptive statistics represent the mean and standard deviation of the per-participant percentage of cocaine-negative urine specimens, computed across participants within each arm. | Results for the TAU arm are summarized using descriptive statistics but are omitted from statistical comparisons due to insufficient data (n = 4, with 2 out of 4 withdrawn from the study). | Posted | Mean | Standard Deviation | % negative specimens per participant | 12-Week Treatment Interval |
|
from enrollment until 6 months post-treatment, up to 12 months
SAEs are relatively common among individuals with chronic cocaine use disorder, often due to cocaine's adverse effects on cardiovascular and mental health. SAEs occurring during the pre-randomization period are reported under the arm to which participants were ultimately assigned, when applicable. Participants could continue to randomization if still determined eligible. One participant hospitalized during pre-randomization was withdrawn prior to randomization and is therefore not included.
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | Tangible Prize-Based Contingency Management (TangiblePBCM) | For participants assigned to TangiblePBCM, prize draws resulting in one or more small, large, or jumbo wins will result in access to a prize cabinet stocked with small, medium, large, and jumbo financial incentive items. Medium incentive items are included for selection in the event that a patient draws several small prize slips on the same day and are considered equivalent to 4 small prizes. Selection of specific prize items will be informed by patient preference and items will be restocked at least every 2 weeks. The prize cabinet will be open during TangiblePBCM sessions such that prize items are readily visible. Selection of prizes, maintenance of the prize cabinet, and policies regarding prize redemption will follow published guidance on administration of TangiblePBCM within the context of research protocols. |
| Term | Organ System | Source Vocabulary | Assessment Type | Notes | Statistical Information |
|---|---|---|---|---|---|
| hospitalization due to cardiac symptoms | Cardiac disorders | Non-systematic Assessment | Hospitalization for cardiac symptoms, which may occur in the context of cocaine use, other substance use, and/or an underlying medical condition. Not expected to be related to the study interventions, which are behavioral in nature. |
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Predictive analyses of differential treatment response in Tangible vs. Voucher PBCM, a key aim of the broader project, fall outside typical RCT reporting standards and will be reported separately.
Recruitment was significantly impacted by the COVID-19 pandemic, resulting in a smaller sample than originally planned and reduced power.
Outcomes related to delay discounting and theta phase synchronization may vary depending on specific analytic and preprocessing choices.
| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Sarah Forster, PhD | VA Pittsburgh Healthcare System | 412-209-9208 | sarah.forster2@va.gov |
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| Type | Includes Protocol | Includes SAP | Includes ICF | Document Label | Document Date | Document Uploaded Date | Document File Name |
|---|---|---|---|---|---|---|---|
| Prot_SAP | Yes | Yes | No | Study Protocol and Statistical Analysis Plan | Jun 2, 2025 | Jun 9, 2025 | Prot_SAP_000.pdf |
| ICF | No | No | Yes | Informed Consent Form | Nov 17, 2022 | Jun 6, 2025 | ICF_001.pdf |
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| ID | Term |
|---|---|
| D019970 | Cocaine-Related Disorders |
| ID | Term |
|---|---|
| D019966 | Substance-Related Disorders |
| D064419 | Chemically-Induced Disorders |
| D001523 | Mental Disorders |
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| ID | Term |
|---|---|
| D013812 | Therapeutics |
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Participants will be randomly assigned to receive: (1) 12 weeks of TangiblePBCM (n = 70) or (2) 12 weeks of VoucherPBCM (n = 70). CM recipients will also be followed for 6 months post treatment. The proposed design enables evaluation of CM outcome predictors within 140 CM recipients - both with respect to initial treatment response and longer term (6 month) outcomes. All participants will receive a Baseline Assessment prior to the 12 Week Treatment interval, as well as a Follow-up Assessment at the conclusion of this period. Data from Baseline and Follow-up Assessments will enable longitudinal analysis of treatment-related change in EEG and cognitive-behavioral measures in treatment adherent versus treatment non-adherent subgroups.
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| Treatment As Usual Outpatient Substance Use Treatment | Behavioral | All participants will receive treatment as usual outpatient substance use services during the 12-week treatment interval. TAU will specifically entail recommended participation in at least two outpatient group and/or individual psychotherapy encounters per week within the Center for Treatment of Addictive Disorders (CTAD) at VA Pittsburgh Healthcare System. Participants will additionally continue any previously prescribed pharmacotherapy for substance use and/or other mental health conditions, if applicable. |
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| 12-Week Treatment Interval |
| Total Non-CM Treatment Encounters Per Participant | Number of non-CM, recovery-oriented treatment encounters during the 12-week treatment interval, computed on a per-participant basis. Encounters were documented in the electronic health record (VA encounters) and/or self-reported (non-VA encounters, including interactions with mutual support communities). Because this measure reflects the absolute number of non-CM treatment encounters per participant, only individuals with complete data for the 12-week period were included. | 12-Week Treatment Interval |
| % Self-Reported Cocaine-Abstinent Days During Treatment | Percentage of self-reported cocaine-abstinent days during the 12-week treatment interval, computed on a per-participant basis. Only participants with complete self-report data for the full treatment interval were included. | 12-Week Treatment Interval |
| % Self-Reported Drug- and Alcohol-Abstinent Days During Treatment | Percentage of self-reported drug and alcohol-abstinent days during the 12-week treatment interval, computed on a per-participant basis. Only participants with complete self-report data for the full treatment interval were included. | 12-Week Treatment Interval |
| % Self-Reported Stimulant-Abstinent Days at Post-Treatment (CM Groups Only) | Percentage of self-reported stimulant-abstinent days during the 6 month post-treatment interval. For participants without complete data for the full 6-month post-treatment interval, the percentage of self-reported stimulant-abstinent days was computed based on the total number of days for which self-report data were available. | 6 Month Post-Treatment Interval |
| % Self-Reported Drug- and Alcohol-Abstinent Days at Post-Treatment (CM Groups Only) | Percentage of self-reported drug- and alcohol-abstinent days during the 6 month post-treatment interval. For participants without complete data for the full 6-month post-treatment interval, the percentage of self-reported stimulant-abstinent days was computed based on the total number of days for which self-report data were available. | 6 Month Post-Treatment Interval |
| Baseline and Post-Treatment Follow-up |
| Difference in Executive Working Memory From Baseline to Post-Treatment | Difference in Brown-Peterson working memory scores between baseline and post-treatment (i.e., follow-up assessment conducted after the conclusion of the 12-week treatment interval). We will specifically use a modified Brown-Peterson test (Auditory Consonant Trigrams) for which both age- and Veteran-specific norms exist. Summary scores for this measure (including 9-, 18-, and 36-second delay conditions) can range from 0-45, with higher scores indicating improved executive working memory performance. | Baseline and Post-Treatment Follow-up |
| Difference in Episodic Future Thinking Effect on Delay Discounting From Baseline to Post-Treatment | Delay discounting was quantified using the hyperbolic discounting parameter (k), estimated separately for the Episodic Future Thinking (EFT) condition-with personally meaningful event tags anchoring delayed rewards-and the Standard condition without such tags. Values of k were natural log-transformed (ln(k)), with higher ln(k) indicating steeper discounting of delayed rewards, reflecting greater devaluation of future outcomes and a stronger preference for immediate gratification. | Baseline and Post-Treatment Follow-up |
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| COMPLETED |
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| BG001 | Voucher Prize-Based Contingency Management (VoucherPBCM) | Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to VoucherPBCM, prize draws resulting in small, large, or jumbo wins are rewarded with VA Canteen vouchers of corresponding value. These vouchers can be redeemed at Veterans Canteen Service vendors, including the hospital cafeteria and Patriot Store. |
| BG002 | Treatment As Usual (TAU) | A treatment-as-usual (TAU) arm was originally included in the study design but was discontinued early in the trial due to evidence that its inclusion adversely affected participant accrual and retention among treatment-seeking individuals with cocaine use disorder. Participants randomized to TAU received standard care without the addition of prize-based contingency management (PBCM). Although they were still required to submit urine samples twice weekly for testing, they did not receive therapeutic incentives based on their urinalysis results. |
| BG003 | Total | Total of all reporting groups |
| age in years |
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| Sex: Female, Male | Count of Participants | Participants |
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| Ethnicity (NIH/OMB) | Count of Participants | Participants |
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| Race (NIH/OMB) | Count of Participants | Participants |
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| Region of Enrollment | Number | Participants |
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| % Self-Reported Pre-Treatment Cocaine-Abstinent Days | Values reflect retrospective reports of past-month substance use, obtained via the Timeline Follow-Back procedure at baseline. Notably, some participants were in controlled environments during this period, which may have led to inflated estimates of cocaine-abstinent days relative to what might be expected in the outpatient setting where PBCM was delivered in the current study. | Mean | Standard Deviation | % cocaine-abstinent days (past month) |
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| % Self-Reported Pre-Treatment Drug- and Alcohol-Abstinent Days | Values reflect retrospective reports of past-month substance use, obtained via the Timeline Follow-Back procedure at baseline. Notably, some participants were in controlled environments during this period, which may have led to inflated estimates of drug and alcohol-abstinent days relative to what might be expected in the outpatient setting where PBCM was delivered in the current study. | Mean | Standard Deviation | % fully abstinent days (past month) |
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| Tangible Prize-Based Contingency Management (TangiblePBCM) |
Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to TangiblePBCM, prizes are awarded in the form of tangible items, which are chosen from a physical "prize cabinet." Participants may redeem their draws for small, medium, large, or jumbo prizes, with medium prizes valued at approximately 5 small prizes. The cabinet is visible during sessions and restocked regularly, and the selection of prizes is guided by patient preference. All participants continue to receive their usual outpatient treatment and medications alongside PBCM. |
| OG001 | Voucher Prize-Based Contingency Management (VoucherPBCM) | Participants in this condition will receive Prize-Based Contingency Management (PBCM) as an adjunct to treatment as usual (TAU). During twice-weekly sessions, urine samples will be tested for cocaine, and each negative result earns the participant draws from a bowl of 500 paper slips, 250 of which award small, large, or jumbo prizes (the remaining slips deliver words of encouragement). Each consecutive negative adds an additional draw (up to 8), while a positive or missed test resets the draw count. For participants assigned to VoucherPBCM, prize draws resulting in small, large, or jumbo wins are rewarded with VA Canteen vouchers of corresponding value. These vouchers can be redeemed at Veterans Canteen Service vendors, including the hospital cafeteria and Patriot Store. |
| OG002 | Treatment As Usual (TAU) | A treatment-as-usual (TAU) arm was originally included in the study design but was discontinued early in the trial due to evidence that its inclusion adversely affected participant accrual and retention among treatment-seeking individuals with cocaine use disorder. Participants randomized to TAU received standard care without the addition of prize-based contingency management (PBCM). Although they were still required to submit urine samples twice weekly for testing, they did not receive therapeutic incentives based on their urinalysis results. |
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| Primary | Longest Duration of Cocaine Abstinence (LDCA) | Longest period of objectively-verified abstinence from cocaine during treatment. It is noted that two TAU participants withdrew during the 12-week treatment interval. For these participants, the LDCA was computed for the pre-withdrawal period only. | Results for the TAU arm are summarized using descriptive statistics but are omitted from statistical comparisons due to insufficient data (n = 4, with 2 out of 4 withdrawn from the study). | Posted | Mean | Standard Deviation | LDCA in days | 12-Week Treatment Interval |
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| Secondary | % Contingency Management (CM) Sessions Attended Per Participant (CM Groups Only) | Percentage of CM treatment sessions attended out of the total number possible, computed on a per-participant basis. The denominator was adjusted for participants for whom a full course of treatment could not be delivered due to suspension of face-to-face research activities during the COVID-19 pandemic. Descriptive statistics represent the mean and standard deviation of the per-participant percentage of CM sessions attended, computed across participants within each arm. | Posted | Mean | Standard Deviation | % CM sessions attended per participant | 12-Week Treatment Interval |
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| Secondary | Total Non-CM Treatment Encounters Per Participant | Number of non-CM, recovery-oriented treatment encounters during the 12-week treatment interval, computed on a per-participant basis. Encounters were documented in the electronic health record (VA encounters) and/or self-reported (non-VA encounters, including interactions with mutual support communities). Because this measure reflects the absolute number of non-CM treatment encounters per participant, only individuals with complete data for the 12-week period were included. | Only participants with complete data for the 12-week treatment period were included in this measure. Accordingly, two participants who withdrew early were excluded from the TAU arm, and one participant was excluded from the TangiblePBCM arm due to missing data. Results for the TAU arm are summarized using descriptive statistics but are omitted from statistical comparisons due to insufficient data (n = 4, with 2 out of 4 withdrawn from the study). | Posted | Mean | Standard Deviation | count of encounters per participant | 12-Week Treatment Interval |
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| Secondary | % Self-Reported Cocaine-Abstinent Days During Treatment | Percentage of self-reported cocaine-abstinent days during the 12-week treatment interval, computed on a per-participant basis. Only participants with complete self-report data for the full treatment interval were included. | Two participants were excluded from each arm (TangiblePBCM, VoucherPBCM, TAU) due to missing self-reported substance use data (collected via timeline follow-back procedure) during the 12-week treatment interval. All participants included had complete self-report data for the full interval. Results for the TAU arm are summarized using descriptive statistics but are omitted from statistical comparisons due to insufficient data (n = 4, with 2 out of 4 withdrawn from the study). | Posted | Mean | Standard Deviation | % cocaine abstinent days | 12-Week Treatment Interval |
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| Secondary | % Self-Reported Drug- and Alcohol-Abstinent Days During Treatment | Percentage of self-reported drug and alcohol-abstinent days during the 12-week treatment interval, computed on a per-participant basis. Only participants with complete self-report data for the full treatment interval were included. | Two participants were excluded from each arm (TangiblePBCM, VoucherPBCM, TAU) due to missing self-reported substance use data (collected via timeline follow-back procedure) during the 12-week treatment interval. All participants included had complete self-report data for the full interval. Results for the TAU arm are summarized using descriptive statistics but are omitted from statistical comparisons due to insufficient data (n = 4, with 2 out of 4 withdrawn from the study). | Posted | Mean | Standard Deviation | % drug and alcohol abstinent days | 12-Week Treatment Interval |
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| Secondary | % Self-Reported Stimulant-Abstinent Days at Post-Treatment (CM Groups Only) | Percentage of self-reported stimulant-abstinent days during the 6 month post-treatment interval. For participants without complete data for the full 6-month post-treatment interval, the percentage of self-reported stimulant-abstinent days was computed based on the total number of days for which self-report data were available. | Posted | Mean | Standard Deviation | % stimulant-abstinent days | 6 Month Post-Treatment Interval |
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| Secondary | % Self-Reported Drug- and Alcohol-Abstinent Days at Post-Treatment (CM Groups Only) | Percentage of self-reported drug- and alcohol-abstinent days during the 6 month post-treatment interval. For participants without complete data for the full 6-month post-treatment interval, the percentage of self-reported stimulant-abstinent days was computed based on the total number of days for which self-report data were available. | Posted | Mean | Standard Deviation | % drug and alcohol abstinent days | 6 Month Post-Treatment Interval |
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| Other Pre-specified | Difference in Control-related Theta Synchronization From Baseline to Post-Treatment | Theta synchronization between anterior cingulate cortex (Cz) and lateral prefrontal cortex (F3, F4, FC5, FC6) was measured to assess differences in functional connectivity between baseline and post-treatment (i.e., follow-up assessment conducted after the conclusion of the 12-week treatment interval) for high versus low conflict events. At each timepoint, phase locking value (PLV) was computed for 4 electrode pairs (Cz-F3, Cz-F4, Cz-FC5, Cz-FC6) across 3 stimulus conditions ranging from low to high conflict (Congruent, Intermediate-Incongruent, High-Incongruent) and for high-conflict error versus low-conflict correct responses in the Parametric Conflict Flankers task. A wavelet transformation isolated theta activity, and PLV was derived from normalized complex wavelet phases. PLV quantifies trial-to-trial phase synchrony (0-1), with 1 representing perfect synchrony. Descriptive data reported below represent the average PLV across the 4 electrode pairs. | To accommodate the smaller final sample relative to the original target, analyses of neural and cognitive-behavioral outcomes were combined across arms. A revised analytic plan, approved prior to analysis, examined longitudinal differences by treatment engagement (attendance) and abstinence across arms. | Posted | Mean | Standard Deviation | Phase Locking Value | Baseline and Post-Treatment Follow-up |
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| Other Pre-specified | Difference in Executive Working Memory From Baseline to Post-Treatment | Difference in Brown-Peterson working memory scores between baseline and post-treatment (i.e., follow-up assessment conducted after the conclusion of the 12-week treatment interval). We will specifically use a modified Brown-Peterson test (Auditory Consonant Trigrams) for which both age- and Veteran-specific norms exist. Summary scores for this measure (including 9-, 18-, and 36-second delay conditions) can range from 0-45, with higher scores indicating improved executive working memory performance. | To accommodate the smaller final sample relative to the original target, analyses of neural and cognitive-behavioral outcomes were combined across arms. A revised analytic plan, approved prior to analysis, examined longitudinal differences by treatment engagement (attendance) and abstinence across arms. | Posted | Mean | Standard Deviation | total score | Baseline and Post-Treatment Follow-up |
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| Other Pre-specified | Difference in Episodic Future Thinking Effect on Delay Discounting From Baseline to Post-Treatment | Delay discounting was quantified using the hyperbolic discounting parameter (k), estimated separately for the Episodic Future Thinking (EFT) condition-with personally meaningful event tags anchoring delayed rewards-and the Standard condition without such tags. Values of k were natural log-transformed (ln(k)), with higher ln(k) indicating steeper discounting of delayed rewards, reflecting greater devaluation of future outcomes and a stronger preference for immediate gratification. | To accommodate the smaller final sample relative to the original target, analyses of neural and cognitive-behavioral outcomes were combined across arms. A revised analytic plan, approved prior to analysis, examined longitudinal differences by treatment engagement (attendance) and abstinence across arms. | Posted | Mean | Standard Deviation | ln(k) delay discounting parameter | Baseline and Post-Treatment Follow-up |
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| 1 |
| 22 |
| 5 |
| 22 |
| 0 |
| 22 |
| EG001 | Voucher Prize-Based Contingency Management (VoucherPBCM) | For participants assigned to VoucherPBCM, prize draws resulting in one or more small, large, or jumbo wins will be reinforced with VA Canteen vouchers in the specified incentive range (i.e., small, large, or jumbo). | 0 | 19 | 5 | 19 | 0 | 19 |
| EG002 | Treatment As Usual (TAU) | A treatment-as-usual (TAU) arm was originally included in the study design but was discontinued early in the trial due to evidence that its inclusion adversely affected participant accrual and retention among treatment-seeking individuals with cocaine use disorder. Participants randomized to TAU received standard care without the addition of prize-based contingency management (PBCM). Although they were still required to submit urine samples twice weekly for testing, they did not receive therapeutic incentives based on their urinalysis results. | 0 | 4 | 1 | 4 | 0 | 4 |
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| hospitalization for psychiatric symptoms | Psychiatric disorders | Non-systematic Assessment | Hospitalization due to exacerbation of psychiatric symptoms, which may occur in the context of cocaine use, other substance use, or an underlying psychiatric condition. Study interventions are not expected to increase the risk of such events. |
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| initial or prolonged hospitalization due to stroke | Vascular disorders | Non-systematic Assessment | Initial or prolonged hospitalization resulting from stroke or other cerebrovascular event. Not expected to be related to study interventions, which are behavioral in nature. |
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| hospitalization due to acute intoxication | General disorders | Non-systematic Assessment | Hospitalization due to acute intoxication from cocaine or another substance, or for medically supervised detoxification following recent substance use. Study interventions supporting abstinence are not expected to increase the risk of such events. |
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| hospitalization due to neurological symptoms | Nervous system disorders | Non-systematic Assessment | Hospitalization for the treatment of new neurological symptoms and/or pre-existing conditions. Not expected to be related to study interventions, which are behavioral in nature. |
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| hospitalization due to skin infection | Infections and infestations | Non-systematic Assessment | Hospitalization due to an acute skin infection. Not expected to be related to study interventions, which are behavioral in nature. |
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| accidental overdose | General disorders | Non-systematic Assessment | Accidental overdose in the context of cocaine or other substance use. As the study interventions are designed to promote abstinence, they are not anticipated to elevate the risk of such events. |
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Not provided
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| Title | Measurements |
|---|---|
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| Follow-Up Congruent |
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| Follow-Up Intermediate Incongruent |
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| Follow-Up High Incongruent |
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| Baseline Correct |
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| Baseline Error |
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| Follow-Up Correct |
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| Follow-Up Error |
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Due to violations of normality assumptions, a non-parametric Aligned Rank Transform ANOVA was conducted, which does not permit covariates. A median split approach was therefore used to examine the influence of self-reported cocaine abstinence during treatment. The design included 4 factors: time (2 levels), stimulus condition (3 levels), electrode pair (4 levels), and median split group membership (2 levels). Reported results reflect the interaction between time and median split group. |
| ANOVA |
| <0.001 |
| Other |
| Due to violations of normality assumptions, a non-parametric Aligned Rank Transform ANOVA was conducted, which does not permit inclusion of covariates. A median split approach was therefore used to examine the influence of Contingency Management session attendance. The design included 4 factors: time (2 levels), response accuracy (2 levels), electrode pair (4 levels), and median split group membership (2 levels). Reported results reflect the interaction between time and median split group. | ANOVA | 0.022 | Other |
| Due to violations of normality assumptions, a non-parametric Aligned Rank Transform ANOVA was conducted, which does not permit covariates. A median split approach was therefore used to examine the influence of self-reported cocaine abstinence during treatment. The design included 4 factors: time (2 levels), response accuracy (2 levels), electrode pair (4 levels), and median split group membership (2 levels). Reported results reflect the interaction between time and median split group. | ANOVA | 0.024 | Other |
No violations of normality assumptions were identified. A repeated measures ANOVA was conducted. To maintain consistency with other outcome measures, a median split approach was used to examine the potential influence of self-reported cocaine abstinence during the 12-week treatment interval. The design included two factors: time (2 levels) and median split group membership (2 levels). Reported results reflect the interaction between time and median split group. |
| ANOVA |
| 0.662 |
| Other |
| Title | Measurements |
|---|---|
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| Standard ln(k) Follow-up |
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Due to violations of normality assumptions, a non-parametric Aligned Rank Transform ANOVA was conducted, which does not permit inclusion of covariates. A median split approach was therefore used to examine the potential influence of self-reported cocaine abstinence during treatment. The design included 3 factors: time (2 levels), condition (2 levels), and median split group membership (2 levels). Reported results reflect the interaction between time, condition, and median split group. |
| ANOVA |
| 0.645 |
| Other |