Personalized Feedback Intervention Research Articles

Development of a Personalized Feedback Intervention Targeting Pain-Related Anxiety for Adults Reporting Hazardous Drinking and Chronic Pain: A Randomized Controlled Trial.

Among individuals with chronic pain, the rate of hazardous alcohol use is elevated compared to the general population. Yet, hazardous drinkers with chronic pain remain an underserved group. There is a need to develop and test alternative and complementary interventions to reduce hazardous alcohol use among this high-risk segment of the general population; targeting pain-related anxiety, a candidate mechanism, is one theoretically-informed route. Our approach followed a staged model (1a/1b) to develop and test a novel personalized feedback intervention (PFI). Phase 1A collected qualitative feedback from (N = 9; 77.8% female, Mage = 33.86, SD = 8.75) participants to refine intervention content and evaluate treatment acceptability and feasibility. For phase 1B, individuals (N=118; 57.3% male, Mage = 35.24, SD = 11.90) participated in a pilot randomized clinical trial for our novel PFI compared to a health information control condition on alcohol use, intention/motivation to reduce drinking, pain-related anxiety, and expectancies for alcohol analgesia/pain coping for hazardous drinkers with chronic pain. Phase 1a results provided support for the feasibility of using a PFI to target pain-related anxiety, and results from Phase 1b indicated that participants reduced drinking and primary outcomes changed in the expected directions, but there were no differential effects of the intervention. The current data provide preliminary evidence for the utility of computer-based brief interventions to encourage behavior change. However, further refinement of the intervention to target pain-related anxiety is warranted.

Does self-affirmation augment the effects of a mandated personalized feedback intervention? A randomized controlled trial with heavy drinking college students.

Theory and evidence indicate that affirming the value of the self before exposure to a threatening message fosters more open-minded appraisal of message content. We predicted that college students mandated to a computer-delivered personalized feedback intervention (PFI) and who engaged in a self-affirmation (SA) exercise would demonstrate reduce drinking and consequences relative to those who received an attention control. Participants were 484 undergraduates (age 18-24, 56% male, 78% White) mandated to participate in an alcohol intervention following a first-time alcohol policy violation. After a baseline assessment, each was randomized to SA (n = 256) or attention control (n = 227) prior to a computer-delivered PFI intervention. Posttest measures included an affirmation manipulation check; primary outcomes (past month weekly quantity, peak drinks, binge frequency, consequences) were assessed at 1-, 3-, 6-, 9-, and 12-month follow-ups. We used latent growth curve modeling to test study hypotheses. The SA exercise increased positive self-evaluation at posttest (p < .001). Overall reductions in drinking and consequences were observed at early follow-up (all p < .05), but the SA manipulation was not associated with intercept or slope factor differences in the models. Engaging in assessments during COVID restrictions was generally associated with reduced drinking and consequences. The SA exercise did not differentially affect trajectories of alcohol use and consequences, despite evidence that the exercise had the predicted effect on participant's self-evaluations. The lack of SA effects could be attributed to a nonthreatening PFI intervention that is generally accepted among mandated students. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Supplemental Material for Does Self-Affirmation Augment the Effects of a Mandated Personalized Feedback Intervention? A Randomized Controlled Trial With Heavy Drinking College Students

Supplemental Material for Does Self-Affirmation Augment the Effects of a Mandated Personalized Feedback Intervention? A Randomized Controlled Trial With Heavy Drinking College Students

A pilot study of the acceptability, efficacy, and iatrogenic effects of a brief dynamic norms intervention for reducing young adult alcohol use.

Alcohol use and its related consequences are a public health problem among young adults. Building upon efficacious personalized normative feedback interventions, dynamic norms can be used to highlight the decreasing prevalence of alcohol use over time among young adults' peers, thereby increasing their motivation to change drinking consistent with the trend. Because limited research has examined dynamic norms feedback interventions for alcohol use, we examined the acceptability and initial efficacy of such an intervention, and potential iatrogenic effects of showing norms feedback about drinking to light drinkers and nondrinkers. Participants were 546 unvaccinated young adults ages 18-24 who completed a baseline survey, intervention, and 1-month follow-up assessment. Participants were block randomized to receive a brief web-based dynamic norms intervention, with feedback content focused on either (a) alcohol-related behaviors (intervention) or (b) COVID-19 vaccine behaviors (the attention-matched control for the present study). On average, participants who received the alcohol intervention rated it as generally engaging, helpful, and acceptable, with the majority (90.8%) indicating that they would recommend it to a friend. Supporting initial efficacy, in generalized linear models controlling for demographics and baseline alcohol outcomes, at 1-month follow-up the alcohol intervention was associated with statistically and clinically significant reductions in all indices of perceived drinking norms, drinking quantity, drinking frequency, and driving after drinking occasions. Lighter drinkers showed no adverse iatrogenic effects. Presenting alcohol-related personalized normative feedback using dynamic trends is a promising intervention for reducing alcohol use in a community sample of young adults. Further research clarifying the optimal presentation of dynamic norms is needed.

Personalized feedback intervention for individuals with low distress tolerance who smoke cigarettes: A randomized controlled trial of a digital intervention

IntroductionCigarette smoking remains the leading preventable cause of death and disability in the United States and frequently co-occurs with anxiety and depressive symptoms. A novel and integrative, theory-driven approach to address the heterogeneity of mood-related symptoms associated with cigarette use is to focus on transdiagnostic processes, such as distress tolerance, that underpin both mood-related symptoms and smoking behavior. The current study sought to develop and examine the feasibility, acceptability, and initial efficacy of a digitally delivered integrated personalized feedback intervention (PFI) that addresses smoking-distress tolerance relations. MethodsParticipants included 121 adults (71.1 % male; Mage = 29.33 years, SD = 7.52) who smoked cigarettes daily and reported low distress tolerance. The study randomized participants to the Active PFI (feedback on distress tolerance and smoking) or the Control PFI (feedback on smoking only). ResultsResults indicated feasibility and acceptability demonstrated by the ability to retain participants through the 1-month follow-up (98.2 % retention rate) and positive feedback from participants, including satisfaction regarding the Active PFI. The Active PFI (vs. Control PFI) was also a statistically significant predictor of change in motivation and intention to quit smoking and willingness to use adaptive coping strategies from baseline to 1-month follow-up. ConclusionsFor individuals with low distress tolerance who smoke cigarettes, this study's findings suggest that the current intervention may be a first-step to aid in increasing motivation/intention to quit smoking and willingness to use adaptive coping strategies.

Injunctive and descriptive normative feedback for college drinking prevention: Is the whole greater than the sum of its parts?

Single-component personalized normative feedback (PNF) interventions and multicomponent personalized feedback interventions (PFI) have been shown to reduce alcohol consumption among college students. The present study compared the efficacy of PNF interventions targeting descriptive norms alone (descriptive PNF), injunctive norms alone (injunctive PNF), or their combination (combined PNF), against a multicomponent PFI and an attention control condition. Undergraduates (N = 1,137) across two universities who reported a minimum of one past-month episode of heavy episodic drinking (i.e., 4 +/5 + drinks on a single occasion for females/males) completed assessments at baseline and 3, 6, and 12 months postintervention. Relative to the attention control, participants in each of the four intervention conditions showed greater reductions in perceived descriptive/injunctive norms, total drinks per week, and alcohol-related consequences. Peak estimated blood alcohol concentration was also reduced in the injunctive PNF, combined PNF, and multicomponent PFI conditions, with the latter two conditions showing an advantage for duration of effects. The multicomponent PFI condition also evidenced greater reductions than the injunctive PNF in descriptive norms at 3-month and injunctive norms at 6- and 12-month follow-ups. No other group comparisons on any outcome were significant. Each intervention has merit for use in college student harm reduction efforts. Single-component or combined PNF could be considered a potential starting point, as PNF is less burdensome than a multicomponent PFI when considering ease and length of delivery. Results can inform optimization of norms-based interventions and guide recommendations on efficacious components for reducing alcohol use and harms on college campuses. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Cross-Tailoring Integrative Alcohol and Risky Sexual Behavior Feedback for College Students: Protocol for a Hybrid Type 1 Effectiveness-Implementation Trial.

Underage drinking and related risky sexual behavior (RSB) are major public health concerns on United States college campuses. Although technology-delivered personalized feedback interventions are considered a best practice for individual-level campus alcohol prevention, there is room for improving the effectiveness of this approach with regard to alcohol-related RSB. The aims of the present study are to (1) evaluate the impact of a brief, personalized feedback intervention (PFI) that integrates content on alcohol use and RSB and is adapted to include a novel cross-tailored, dynamic feedback (CDF) component for at-risk first-year college students and (2) identify implementation factors critical to the CDF's success to facilitate future scale-up in campus settings. This study utilizes a hybrid type 1 effectiveness-implementation design and will be conducted in three phases. Phase 1 is a stakeholder-engaged PFI+CDF adaptation guided by focus groups and usability testing. In Phase 2, 600 first-year college students who drink and are sexually active will be recruited from two sites (n=300 per site) to participate in a 4-group randomized controlled trial to examine the effectiveness of PFI+CDF in reducing alcohol-related RSB. Eligible participants will complete a baseline survey during the first week of the semester and follow-up surveys at 1, 2, 3, 6, and 13 months postbaseline. Phase 3 is a qualitative evaluation with stakeholders to better understand relevant implementation factors. Recruitment and enrollment for Phase 1 began in January of 2022. Recruitment for Phases 2 and 3 is planned for the summer of 2023 and 2024, respectively. Upon collection of data, the effectiveness of PFI+CDF will be examined, and factors critical to implementation will be evaluated. This hybrid type 1 trial is designed to impact the field by testing an innovative adaptation that extends evidence-based alcohol programs to reduce alcohol-related RSB and providing insights related to implementation to bridge the gap between research and practice at the university level. ClinicalTrials.gov NCT05011903; https://clinicaltrials.gov/ct2/show/NCT05011903.

Evaluation of an integrated personalized feedback intervention for hazardous drinkers with elevated anxiety sensitivity and PTSD symptoms: Protocol for a randomized controlled trial

BackgroundHazardous drinking and posttraumatic stress disorder (PTSD) are commonly co-occurring conditions among adults. Motivational enhancement interventions, such as personalized feedback interventions (PFI), have demonstrated efficacy for reducing hazardous drinking. Emerging though scant literature has evaluated PFI for co-occurring PTSD and hazardous alcohol use. A transdiagnostic risk factor that may underlie this co-occurrence and inform novel PFI development is anxiety sensitivity (AS). ObjectiveTo use a randomized controlled trial to evaluate the efficacy of a novel, computer-based PFI for hazardous drinkers with at least subclinical PTSD and elevated AS (AP-PFI), against a time-matched comparison condition (C-PFI). MethodsParticipants (N = 100) will be recruited and enrolled from the Houston, TX community. The study includes: an in-person visit (baseline diagnostic assessment, a brief intervention, and a post-intervention assessment) and two follow-up assessments (1-week and 1-month). Participants who meet study inclusion criteria will be randomized to one of two conditions at baseline: AP-PFI or C-PFI. AP-PFI will consist of a brief, single-session, computer-delivered, PFI-based intervention that provides integrative and normative feedback about alcohol use, AS, and PTSD symptoms. C-PFI will be time-matched but will only include alcohol-related feedback. ConclusionsAP-PFI is designed to provide feedback about alcohol use, PTSD symptoms, and AS and their interplay and deliver psychoeducation on harm-reduction techniques, interoceptive exposure exercises, and stress management strategies. The intervention may address extant gaps in treatment for these co-occurring conditions by providing a brief, evidence-based, motivational enhancement intervention that is cost-effective with potential to be disseminated across a variety of healthcare settings.

Enhancing distress tolerance to uplift motivation in recovery: Results from an open development trial.

This open pilot study examines the feasibility, acceptability, and qualitative outcomes of an interactive web- and text message-delivered personalized feedback intervention aimed at cultivating motivation and tolerance of distress for adults initiating outpatient buprenorphine treatment. Patients (n = 10) initiating buprenorphine within the past 8 weeks first completed a web-based intervention focused on enhancing motivation and providing psychoeducation on distress tolerance skills. Participants then received 8 weeks of daily personalized text messages that provided reminders of salient motivational factors and recommended distress tolerance-oriented coping skills. Participants completed self-report measures to assess intervention satisfaction, perceived usability, and preliminary efficacy. Additional perspectives were captured via qualitative exit interviews. In total, 100% of retained participants (n = 9) engaged with the text messages throughout the entire 8-week period. Mean scores of 27 (SD = 5.05) on the Client Satisfaction Questionnaire at the end of 8-week period indicated a high degree of satisfaction with the text-based intervention. The average rating on the System Usability Scale was 65.3 at the end of the 8-week program, suggesting that the intervention was relatively easy to use. Participants also endorsed positive experiences with the intervention during qualitative interviews. Clinical improvements were observed across the intervention period. Preliminary findings from this pilot suggest that the content and delivery method of this combined web- and text message-based personalized feedback intervention is perceived by patients as feasible and acceptable. Leveraging digital health platforms to augment buprenorphine has potential for high scalability and impact to reduce opioid use, increase adherence/retention to treatment, and prevent future incidence of overdose. Future work will evaluate the efficacy of the intervention in a randomized clinical trial design.

Does abstaining from alcohol in high school moderate intervention effects for college students? Implications for tiered intervention strategies.

Brief motivational intervention (BMI) and personalized feedback intervention (PFI) are individual-focused brief alcohol intervention approaches that have been proven efficacious for reducing alcohol use among college students and young adults. Although the efficacy of these two intervention approaches has been well established, little is known about the factors that may modify their effects on alcohol outcomes. In particular, high school drinking may be a risk factor for continued and heightened use of alcohol in college, and thus may influence the outcomes of BMI and PFI. The purpose of this study was to investigate whether high school drinking was associated with different intervention outcomes among students who received PFI compared to those who received BMI. We conducted moderation analyses examining 348 mandated students (60.1% male; 73.3% White; and 61.5% first-year student) who were randomly assigned to either a BMI or a PFI and whose alcohol consumption was assessed at 4-month and 15-month follow-ups. Results from marginalized zero-inflated Poisson models showed that high school drinking moderated the effects of PFI and BMI at the 4-month follow-up but not at the 15-month follow-up. Specifically, students who reported no drinking in their senior year of high school consumed a 49% higher mean number of drinks after receiving BMI than PFI at the 4-month follow-up. The results suggest that alcohol consumption in high school may be informative when screening and allocating students to appropriate alcohol interventions to meet their different needs.

The Impact of Personalized Feedback Interventions by a Gambling Operator on Subsequent Gambling Expenditure in a Sample of Dutch Online Gamblers

Player protection has become an important area for the gambling industry over the past decade. A number of gambling regulators now require gambling operators to interact with customers if they suspect they are gambling in a problematic way. The present study provided insight on the impact of personalized feedback interventions (PFIs) on subsequent gambling behavior among a Dutch sample of real-world gamblers. Nederlandse Loterij (the national Dutch Lottery operator) provided access to a secondary dataset comprising tracking data from online casino and sports betting gamblers (N = 2,576) who were contacted either by e-mail or telephone between November 2021 and March 2022 if they showed signs of problematic gambling as identified using behavioral tracking software. Compared to matched controls (n = 369,961 gamblers), Dutch gamblers who received a PFI (via e-mail [n = 1876] or a telephone call [n = 700]) from the gambling operator had a significant reduction in amount of money deposited, amount of money wagered, number of monetary deposits, and time spent gambling in the 30 days after being contacted. Gambling frequency as measured by the number of gambling days did not change significantly after a PFI. Telephone calls did not lead to a significant larger reduction with respect to the aforementioned behavioral metrics. High-intensity players reduced their gambling behavior as frequently as low-intensity players, which means that the intervention’s success was independent of gambling intensity. The impact on subsequent gambling was the same across age groups and gender. The results of the present study are of use to many different stakeholder groups including researchers in the gambling studies field and the gambling industry as well as regulators and policymakers who can recommend or enforce that gambling operators utilize responsible gambling tools such as using PFIs to those who may be displaying problematic gambling behaviors as a way of minimizing harm and protecting gamblers.

37.3 Brief Interventions to Reduce the Nonmedical Use of Prescription Stimulants Among College Students: Project PHARM (Personalized Health Assessment Related to Medications)

Project PHARM (Personalized Health Assessment Related to Medications) is a multicampus, collaborative study addressing the nonmedical use of prescription stimulants. Students from 9 colleges and universities across the United States were recruited to document norms of the nonmedical use of prescription stimulants and to evaluate the efficacy of a web-delivered personalized feedback intervention (PFI) that primarily targeted nonmedical prescription stimulant use (including norms, perceived benefits of nonmedical use, motives for nonmedical use, and alternatives to nonmedical use) yet also addressed alcohol and cannabis use.

Social network moderators of brief alcohol intervention impact.

This investigation examined the impact of social networks on drinking reduction efforts following a brief alcohol intervention. In a reanalysis of data from an earlier randomized controlled trial with nonstudent emerging adult drinkers (Lau-Barraco et al., 2018), we aimed to test three domains of preintervention social network features as potential factors influencing intervention response: (a) general network characteristics (i.e., network size, network stability), (b) general network alcohol use (i.e., network alcohol abstainers, network heavy/problem drinkers), and (c) risky peers in network (i.e., proportion of drinking buddies, presence of drinking buddies identified as heavy/problem drinker). Participants were 164 emerging adult heavy drinkers recruited from the community (65.9% men; mean age = 21.98 years; 56.2% ethnic minority). Participants were randomly assigned to either a brief personalized feedback intervention (PFI) or assessment-only control and provided data at 1-month and 3-month follow-ups. Greater network stability and greater representation of alcohol abstainers in one's social network were associated with improved initial postintervention response. Heavy/problem drinkers in the network did not moderate initial postintervention effects on drinking outcomes, but there was potentially a stronger intervention effect on risk reduction for those with higher proportions of drinking buddies in their network. Study findings provided evidence that a PFI was efficacious in mitigating some risky social network influence. However, findings did not support a consistent impact across all the network variables examined. Future research is needed to further clarify social network influences and how they may be targeted to enhance intervention efficacy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Who Opts In to Alcohol Feedback and How Does That Impact Behavior? A Pilot Trial.

Personalized feedback interventions are effective in reducing alcohol consumption and related problems. However, little is known about the role of choice in outcomes. The current study sought to (a) characterize individuals who opt in for brief alcohol-related feedback, (b) assess participants' consistency in that choice over two time points, and (c) evaluate changes in peak alcohol consumption among those who did and did not receive feedback. Participants reporting past-12-month alcohol consumption were recruited through Prolific. At the outset of the survey, participants were asked if they would like to receive feedback on their drinking at the end of the survey ("opt in"). Participants at Time 1 (T1; N = 732) were 41% female, 91% White, and 8% Hispanic (mean age = 36, SD = 12.25, range: 18-80). A subset was invited back for a 30-day retest (Time 2 [T2]; n = 234). Those reporting higher maximum drinks and more drug use were more likely to opt in to feedback than those with lower use. Further, 85% of participants were consistent in their choice of whether to receive feedback across T1 and T2 (κ = .65). Among heavy drinking participants with T1 and T2 data (n = 163), there was an effect of feedback on intensity of consumption at T2. Individuals who engage in heavy alcohol use are more likely to opt in to personalized alcohol feedback, and most do so consistently. Among heavy drinkers, feedback at T1 reduced intensity of consumption at T2, but the effect was small and requires future replication in more diverse samples.

Examining the viewing pattern of Web-delivered personalized feedback interventions aimed at reducing alcohol-related risky sexual behavior among young adults

Objective The present study examined young adults’ completion of the Web-based intervention content in a randomized trial that tested two Personalized Feedback Interventions (PFIs) for alcohol use and risky sex behavior (RSB). Method Data are from a study that evaluated efficacy of two Web-delivered PFIs (combined PFI and integrated PFI) among 269 sexually active young adults between the ages of 18 and 25. We described the view patterns of the Web-based intervention and examined if baseline sociodemographic and alcohol- and sex-related behavioral factors were associated with the completion of PFI. Results Many participants viewed the intervention more than one time, and the majority finished all intervention pages in at least one session. Older participants and participants who drink more frequently prior to or during sex were more likely to complete. Conclusions Most participants, especially the young adults who were at higher risk, utilized the intervention contents as intended.

Open trial of a personalized feedback intervention and substance-free activity supplement for veterans with PTSD and hazardous drinking.

This study reports findings from an open trial of a two-session intervention for veterans with symptoms of PTSD and hazardous drinking. Rooted in behavioral economic theory, this intervention aimed to decrease alcohol use and increase alcohol-free activities through personalized and normative feedback. This trial assessed the feasibility and acceptability of the intervention in a sample of 15 veterans. Participants completed assessments at baseline and post-intervention (1-month and 3-months). Thirteen participants (86.6%) were retained between the baseline assessment and second intervention session. Acceptability data indicated that veterans overwhelmingly viewed the intervention positively with little dropout between the two sessions. Further, participants in our study reduced alcohol consumption from 37.30 (SD = 17.30) drinks per week at baseline to 22.50 (SD = 27.75) drinks per week at the 1-month assessment and then to 14.60 (SD = 18.64) at the 3-months assessment, representing medium to large effects. PTSD severity also decreased from 57.20 (SD = 16.72) at baseline to 48.90 (SD = 18.99) at the 1-month assessment, representing a small effect. Though effect sizes from pilot trials should be interpreted with caution, findings suggest that this intervention was well-received, feasible to deliver, and may have resulted in improvements in intervention targets.

A Normative Feedback Intervention on Gambling Behavior-A Longitudinal Study of Post-Intervention Gambling Practices in At-Risk Gamblers.

BackgroundIn problem gambling, normative personalized feedback interventions have demonstrated promising effects. Given the widespread increase in online gambling in recent years, internet-delivered normative feedback may serve as a promising intervention. This study aimed to examine whether such an intervention, delivered by a gambling operator and aiming to help problem gamblers decrease their gambling, may in fact be associated with lower gambling practices post-intervention.MethodsOnline questions on norms and beliefs about one's own and peers' gambling habits, derived from the Gambling Quantity and Perceived Norms Scale, were followed by personalized feedback, delivered online by the Swedish state-owned gambling operator. A total of 1,453 gamblers consented to participate in a pre-post measure of wagering levels.ResultsWagering decreased significantly post-intervention (28 days) compared to pre-intervention (28 days prior). The decrease was significantly more pronounced in younger and online casino gamblers. In an 84-day follow-up, the decrease remained significant, although less pronounced.ConclusionsAn online normative intervention delivered by a state-owned gambling operator, addressing norms and beliefs about gambling levels, may lower risky gambling in the short term. Implications and further research needs are discussed.

Incorporating Social Networks and Event-Specific Information in a Personalized Feedback Intervention to Reduce Drinking Among Young Adults.

To correct risky alcohol use among young adults, current personalized feedback interventions (PFIs) use social influence information related to distal referent groups. Although current PFIs have been effective, little consideration has been given to strategies applying more concrete sources of social influence, namely the influence of specific people within one's social network during actual drinking contexts. The current study evaluated a novel PFI, providing feedback regarding the presence or absence of particular individuals within a participant's close network along with the number of drinks consumed and consequences experienced during several specific drinking occasions. TurkPrime users (N = 338) identified five close others with whom they sometimes drank. They also provided details about their five most recent drinking occasions and noted which of their network members were present. Participants were then randomized to receive or not receive feedback consisting of a list of drinking events, negative consequences and who was present. Feedback participants intended to consume fewer drinks over the next month relative to control (b = -0.25, P = 0.001). Analyses were inconclusive as to whether this effect was stronger for those who received more feedback (b = -0.01, P = 0.857). Results provide preliminary support for the efficacy of a novel social influence-based intervention, which provides personalized feedback indicating social contexts that are more and less likely to lead to negative alcohol-related experiences.

Online personalized feedback intervention to reduce risky cannabis use. Randomized controlled trial

Background and aimsGiven the widespread use of cannabis, and the concomitant risks associated with the drug, there is a need to increase the availability of interventions designed to reduce risky cannabis use. One promising intervention in the addictions employs personalized normative feedback to motivate change. MethodsA two-arm randomized controlled trial (RCT) was conducted in which participants who used cannabis in a risky fashion were randomly assigned to one of two groups – those who received an online personalized feedback report in addition to educational materials about risky cannabis use and those who just received the online educational materials. Follow-up assessment occurred at three- and six-months post-randomization. Outcome variables included: number of days cannabis was used in the past 30, risky cannabis use (ASSIST score of four or more), and participant estimates of the proportion of cannabis users among those of the same age and gender. ResultsA total of 744 participants with risky cannabis use were recruited for the trial using online advertisements. There were no significant differences between intervention and educational materials only groups at three- and six-month follow-ups for the outcome variables, number of days used cannabis in the last 30 (p = 0.927) and proportion of participants engaging in risky cannabis use (p = 0.557). At three and six month follow-ups, participants who received the feedback intervention were more likely than those in the educational materials group to estimate that a larger proportion of people their age and gender did not use cannabis in the last year (p = 0.028). Discussion and conclusionWhile there was some evidence that the personalized feedback intervention modified normative perceptions about cannabis use, there did not appear to be support for the prediction that the intervention reduced cannabis consumption.

A Structural Equation Modeling Approach to Meta-analytic Mediation Analysis Using Individual Participant Data: Testing Protective Behavioral Strategies as a Mediator of Brief Motivational Intervention Effects on Alcohol-Related Problems

This paper introduces a meta-analytic mediation analysis approach for individual participant data (IPD) from multiple studies. Mediation analysis evaluates whether the effectiveness of an intervention on health outcomes occurs because of change in a key behavior targeted by the intervention. However, individual trials are often statistically underpowered to test mediation hypotheses. Existing approaches for evaluating mediation in the meta-analytic context are limited by their reliance on aggregate data; thus, findings may be confounded with study-level differences unrelated to the pathway of interest. To overcome the limitations of existing meta-analytic mediation approaches, we used a one-stage estimation approach using structural equation modeling (SEM) to combine IPD from multiple studies for mediation analysis. This approach (1) accounts for the clustering of participants within studies, (2) accommodates missing data via multiple imputation, and (3) allows valid inferences about the indirect (i.e., mediated) effects via bootstrapped confidence intervals. We used data (N = 3691 from 10 studies) from Project INTEGRATE (Mun et al. Psychology of Addictive Behaviors, 29, 34–48, 2015) to illustrate the SEM approach to meta-analytic mediation analysis by testing whether improvements in the use of protective behavioral strategies mediate the effectiveness of brief motivational interventions for alcohol-related problems among college students. To facilitate the application of the methodology, we provide annotated computer code in R and data for replication. At a substantive level, stand-alone personalized feedback interventions reduced alcohol-related problems via greater use of protective behavioral strategies; however, the net-mediated effect across strategies was small in size, on average.