A preliminary randomized trial of reinforcement contingencies to improve compliance with ecological momentary assessment.

Ecological Momentary Assessment (EMA) methods are increasingly used by translational scientists to study real-world behavior and experience. The ability to draw meaningful conclusions from EMA research depends upon participant compliance with assessment completion. Most EMA studies provide financial compensation for compliance, but little empirical evidence addresses the impact of reinforcement parameters on the level of compliance. The purpose of this study-within-a-trial was to determine the effects of varying the amount and frequency of reinforcement on EMA compliance in a clinical sample of individuals seeking treatment for cigarette smoking. In the parent clinical trial, participants were asked to complete 9 weeks of EMA (1 daily Morning Assessment and 4 daily Random Assessments). Following a 5-week Standard Payment phase for EMA compliance, 61 individuals seeking treatment for cigarette smoking enrolled in the larger clinical trial were randomized to receive Standard ($1 per assessment, paid biweekly), Frequent ($1 per assessment, paid 3 times per week), or Large ($2 per assessment, paid biweekly) payments for EMA compliance during a 4-week Payment Manipulation Phase. Overall, receiving Frequent or Large payments did not improve EMA compliance compared to Standard payments, Ps > .30. Varying frequency and amount of remuneration for EMA compliance did not generally improve compliance in an ongoing clinical trial, raising further questions about the importance of reinforcement parameters in promoting EMA compliance.

Previous studies have addressed the idea that monetary compensation for participation in research is an effective way to encourage individuals to complete the studies. However, there has been limited exploration as whether the amount and frequency of compensation has an influence on participant adherence. We recruited adults who were seeking cigarette smoking treatment and asked them to complete multiple assessments each day on a smartphone app for 9 weeks. Following completion of the assessments, participants were given monetary compensation. A change after 5 weeks led to some persons receiving $1 per assessment paid three times a week (Frequent Payment Group), while others received $2 per assessment paid biweekly (Large Payment Group), and some continued to receive $1 per assessment paid biweekly (Standard Payment Group) for the next 4 weeks. We found that the experimental payment variations did not significantly change compliance with the assessments. These preliminary findings serve as a benchmark for further research.

Comparison of the Bluetooth iCOquit, piCO, and Vitalograph for the assessment of breath carbon monoxide among adults initiating smoking cessation and standardized canisters.

BACKGROUND: The Bluetooth iCOquit enables remote biochemical verification of smoking status, but its validity among adults attempting to quit smoking is unclear. This study 1) compared the iCOquit, piCO, and Vitalograph sensors to identify device-specific bias, 2) assessed the diagnostic accuracy of the iCOquit for the overall sample and within specific subgroups (sex, race, smoking rate, menthol use), and 3) assessed the validity of iCOquit readings against standardized CO canisters. METHODS: iCOquit devices were tested with human breath samples from individuals seeking treatment for combustible tobacco use (N = 93) attending an in-person clinic visit. Participants provided breath samples via the iCOquit, piCO, and Vitalograph (order randomized). iCOquit devices were also tested using 5 and 10 parts per million (ppm) canisters. RESULTS: The iCOquit underestimated CO and categorized more participants as abstinent relative to the other CO sensors with human breath samples. The results suggested the iCOquit could not be used interchangeably with the other CO devices. Using a cut-off of < 6 ppm, the diagnostic accuracy of the iCOquit (specificity = 94%; sensitivity = 85%) did not vary across demographic/smoking subgroups. Canister tests with the iCOquit suggested good precision (< 1 ppm). CONCLUSIONS: The iCOquit is an affordable option for the remote measurement of CO that provides a reasonably accurate assessment of smoking status of those attempting to quit smoking using abstinence cut-off criteria of < 6 ppm. However, compared to other CO monitors, the iCOquit may underestimate CO, thereby increasing error in assessing abstinence.

Evaluating Declines in Compliance With Ecological Momentary Assessment in Longitudinal Health Behavior Research: Analyses From a Clinical Trial.

BACKGROUND: Ecological momentary assessment (EMA) is increasingly used to evaluate behavioral health processes over extended time periods. The validity of EMA for providing representative, real-world data with high temporal precision is threatened to the extent that EMA compliance drops over time. OBJECTIVE: This research builds on prior short-term studies by evaluating the time course of EMA compliance over 9 weeks and examines predictors of weekly compliance rates among cigarette-using adults. METHODS: A total of 257 daily cigarette-using adults participating in a randomized controlled trial for smoking cessation completed daily smartphone EMA assessments, including 1 scheduled morning assessment and 4 random assessments per day. Weekly EMA compliance was calculated and multilevel modeling assessed the rate of change in compliance over the 9-week assessment period. Participant and study characteristics were examined as predictors of overall compliance and changes in compliance rates over time. RESULTS: Compliance was higher for scheduled morning assessments (86%) than for random assessments (58%) at the beginning of the EMA period (P<.001). EMA compliance declined linearly across weeks, and the rate of decline was greater for morning assessments (2% per week) than for random assessments (1% per week; P<.001). Declines in compliance were stronger for younger participants (P<.001), participants who were employed full-time (P=.03), and participants who subsequently dropped out of the study (P<.001). Overall compliance was higher among White participants compared to Black or African American participants (P=.001). CONCLUSIONS: This study suggests that EMA compliance declines linearly but modestly across lengthy EMA protocols. In general, these data support the validity of EMA for tracking health behavior and hypothesized treatment mechanisms over the course of several months. Future work should target improving compliance among subgroups of participants and investigate the extent to which rapid declines in EMA compliance might prove useful for triggering interventions to prevent study dropout. TRIAL REGISTRATION: ClinicalTrials.gov NCT03262662; https://clinicaltrials.gov/ct2/show/NCT03262662.

Types of Traumatic Experiences in Drug Overdose-Related Deaths: An Exploratory Latent Class Analysis.

Aim: Drug overdose related-deaths in the US are increasing, with over 100,000 deaths occurring in 2020, an increase of 30% from the previous year and the highest number recorded in a single year. It is widely known that experiences of trauma and substance use very often co-occur, but little is known about the role of trauma in the context of drug overdose-related deaths. Latent class analysis (LCA) was used to classify drug overdose-related deaths based on type of traumatic experiences and individual, social, and substance use characteristics. Methods: Psychological autopsy data were obtained from the University of Texas Health Science Center at Houston (UTHealth) Brain Collection. A total of 31 drug overdose-related deaths collected from January 2016 through March 2022 were included in this study. LCA was used to identify latent factors via experience of four trauma categories (illness/accidents, sexual/interpersonal violence, death/trauma to another, other situations where life was in danger). Generalized linear modeling (GLM) was used to explore differences on demographic, social, substance use, and psychiatric variables between the latent classes in separate models. Results: LCA identified 2 classes: C1 ( n =12; 39%) was characterized by higher incidence of overall trauma exposure as well as variation in trauma type; C2 ( n =19; 61%) had lower levels of overall trauma exposure with sexual/interpersonal violence as the most frequent. GLMs indicated that C1 membership was associated with higher incidence of polysubstance use, being married, and having suicidal ideation compared to C2 membership ( p s<0.05). Conclusion: Among individuals who died by drug overdose, the exploratory LCA identified two distinct subgroups that differed in type of trauma experienced and substance use pattern, the first group having more "typical" characteristics of drug overdoses cases, the other group less typical. This suggests that those at risk of drug overdose may not always exhibit high-risk characteristics.

A Psychometric Evaluation of the Stanford Expectations of Treatment Scale (SETS) in the Context of a Smoking Cessation Trial.

INTRODUCTION: Although treatment outcome expectancies (TOEs) may influence clinical outcomes, TOEs are rarely reported in the smoking cessation literature, in part because of the lack of validated measures. Therefore, we conducted a psychometric evaluation of TOEs scores with the Stanford Expectations of Treatment Scale (SETS) in the context of a smoking cessation clinical trial. METHODS: Participants were 320 adults enrolled in a randomized controlled trial of extended versus standard pre-quit varenicline treatment for smoking cessation (clinicaltrials.gov ID: NCT03262662). Across an 8-week treatment period, we examined the nature and stability of the factor structure using confirmatory factor analysis (CFA), evaluated discriminant validity by examining correlations with abstinence self-efficacy and positive/negative affect (PA/NA), and assessed internal consistency and test-retest reliability of SETS scores. RESULTS: CFAs supported a 2-factor structure that was stable (ie, invariant) across weeks. Positive and negative TOEs were each reflected in three-item subscales that exhibited acceptable to excellent internal consistency (Cronbach's alphas ≥ .77). Positive and negative TOEs were modestly correlated with PA and NA (all |rs| <.27, p < .05). Positive TOEs, but not negative TOEs, were moderately correlated with abstinence self-efficacy (rs = .45 to .61, p < .01). Both positive and negative TOEs scores demonstrated moderate test-retest reliability between assessments (rs = .54 to .72). CONCLUSIONS: SETS scores generally reflect a valid and reliable assessment of positive and negative TOEs in a sample of adults enrolled in a smoking cessation trial. The SETS appears to be a reasonable option for assessing TOEs in future smoking treatment studies. IMPLICATIONS: Assessments of treatment outcome expectancies are rarely reported in the smoking cessation literature. The present results support the validity and reliability of the SETS scores among adults seeking treatment for their smoking behavior.

Evaluating Treatment Mechanisms of Varenicline: Mediation by Affect and Craving.

INTRODUCTION: Negative reinforcement models posit that relapse to cigarette smoking is driven in part by changes in affect and craving during the quit attempt. Varenicline may aid cessation by attenuating these changes; however, this mediational pathway has not been formally evaluated in placebo-controlled trials. Thus, trajectories of negative affect (NA), positive affect (PA), and craving were tested as mediators of the effect of varenicline on smoking cessation. AIMS AND METHODS: Secondary data analysis was conducted on 828 adults assigned to either varenicline or placebo in a randomized controlled trial for smoking cessation (NCT01314001). Self-reported NA, PA, and craving were assessed 1-week pre-quit, on the target quit day (TQD), and 1 and 4 weeks post-TQD. RESULTS: Across time, NA peaked 1-week post-quit, PA did not change, and craving declined. Less steep rises in NA (indirect effect 95% CI: .01 to .30) and lower mean craving at 1-week post-quit (CI: .06 to .50) were mediators of the relationship between varenicline and higher cessation rates at the end of treatment. PA was associated with cessation but was not a significant mediator. CONCLUSIONS: These results partially support the hypothesis that varenicline improves smoking cessation rates by attenuating changes in specific psychological processes and supported NA and craving as plausible treatment mechanisms of varenicline. IMPLICATIONS: The present research provides the first evidence from a placebo-controlled randomized clinical trial that varenicline's efficacy is due, in part, to post-quit attenuation of NA and craving. Reducing NA across the quit attempt and craving early into the attempt may be important treatment mechanisms for effective interventions. Furthermore, post-quit NA, PA, and craving were all associated with relapse and represent treatment targets for future intervention development.

The impact of three weeks of pre-quit varenicline on reinforcing value and craving for cigarettes in a laboratory choice procedure.

RATIONALE: Varenicline, a partial nicotinic agonist, is theorized to attenuate pre-quit smoking reinforcement and post-quit withdrawal and craving. However, the mechanisms of action have not been fully characterized, as most studies employ only retrospective self-report measures, hypothetical indices of reinforcing value, and/or nontreatment-seeking samples. OBJECTIVES: The current research examined the impact of pre-quit varenicline (vs. placebo) on laboratory measures of smoking and food (vs. water) reinforcement and craving. METHODS: Participants were 162 treatment-seeking smokers enrolled in a randomized controlled trial of smoking cessation ( clinicaltrials.gov ID: NCT03262662). Participants completed two laboratory sessions: a pre-treatment session, ~ 1 week prior to beginning varenicline or placebo, and an active treatment session, after ~ 3 weeks of treatment. At each session, participants completed a laboratory choice procedure; on each of 36 trials, a lit cigarette, food item, or cup of water was randomly presented. Participants reported level of craving and spent $0.01-0.25 to have a corresponding 5-95% chance to sample the cue. RESULTS: As predicted, spending was significantly higher on cigarette trials than water trials, and varenicline resulted in a greater between-session decline in spending on cigarette trials (but not water) than did placebo. Cigarette craving was enhanced in the presence of smoking cues compared to water, but neither average (tonic) cigarette craving nor cue-specific cigarette craving was significantly influenced by varenicline. Food spending and craving were generally unaffected by varenicline treatment. CONCLUSIONS: These laboratory data from treatment-seeking smokers provide the strongest evidence to date that varenicline selectively attenuates smoking reinforcement prior to quitting.

Caffeine enhances sustained attention among adolescents.

Despite the growing interest in caffeine use and its effects among adolescents, and a large literature on caffeine and attention among adults, there is a lack of experimental work examining the impact of caffeine on sustained attention among adolescents. We evaluated the acute effects of caffeine (vs. placebo) during a long (33-min) classic vigilance task among 31 adolescents (aged 12-17; 15 female; median caffeine use = 28 mg/day). We predicted a dose-dependent effect of caffeine, which would attenuate declines in target detection over time (i.e., a vigilance decrement). In each of 3 visits, participants completed an identical pairs continuous performance task beginning ∼25 min after consumption of noncaloric flavored water containing placebo, 1 mg/kg, or 3 mg/kg caffeine (order counterbalanced). Percent hits for low probability targets across 12 100-trial blocks was the primary outcome measure. As predicted, the linear decline in hits across trial blocks was attenuated by caffeine (Caffeine vs. Placebo × Block Linear, p = .01), with significant improvements in Blocks 9-12 (ps < .03). Compared to 1 mg/kg, 3 mg/kg caffeine resulted in earlier improvement in target detection (Drug Dose × Block Quadratic, p = .001). This study demonstrated that caffeine acutely and dose-dependently improves sustained attention among adolescents. These results were likely due to the attention-enhancing effect of caffeine, rather than withdrawal reversal, as our sample was characterized by light to moderate caffeine use. This study provides the foundation for further work on the impact of chronic caffeine consumption on cognitive function during adolescence. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Preliminary Evaluations of Habituation of Operant Responding for Sensory Stimuli in Humans.

Research suggests that repetitive reinforcers wane in their ability to maintain operant behavior in a manner consistent with habituation. Weaker reinforcers, including sensory stimuli common in human work, may be most impacted by repetition. The present research examined within-session operant responding patterns for visual stimuli in humans from two experiments assessing multiple characteristics of habituation. In Experiment 1, declines in reinforced responding were assessed and stimulus specificity was evaluated to test habituation's contribution to these declines. Seventy-three participants completed two visits, both including a reinforcement paradigm using pictures. With repetition, operant responding declined. The stimulus specificity manipulation did not enhance responding, suggesting that habituation did not contribute to response declines. Several methodological concerns may have contributed to the absence of a stimulus specificity effect. Experiment 2 assessed a separate habituation characteristic, rate of stimulation, to address these methodological concerns and further evaluate habituation. Twenty-eight participants completed the reinforcement paradigm over three visits. Decline in responding was partially supported, but the rate of stimulation did not alter declines. In sum, habituation's contribution to within-session declines for sensory reinforcers was not evident in either experiment. These results suggest that assessment of habituation of sensory reinforcers in humans may require parametric evaluation.

Withdrawal Symptom, Treatment Mechanism, and/or Side Effect? Developing an Explicit Measurement Model for Smoking Cessation Research.

INTRODUCTION: Assessment of withdrawal symptoms, treatment mechanisms, and side effects is central to understanding and improving smoking cessation interventions. Though each domain is typically assessed separately with widely used questionnaires to separately assess each domain (eg, Minnesota Nicotine Withdrawal Scale = withdrawal; Questionnaire of Smoking Urges-Brief = craving; Positive and Negative Affect Schedule = affect; symptom checklist = side effects), there are substantial problems with this implicit "one questionnaire equals one construct" measurement model, including item overlap across questionnaires. This study sought to clarify the number and nature of constructs assessed during smoking cessation by developing an explicit measurement model. METHODS: Two subsamples were randomly created from 1246 smokers in a clinical trial. Exploratory and confirmatory factor analyses were conducted to identify and select a model that best represented the data. Measurement invariance was assessed to determine if the factors and their content were consistent prior to and during the quit. Improvement in construct overlap within this model was compared against the implicit measurement model using correlational analyses. RESULTS: A 5-factor measurement model composed of negative affect, somatic symptoms, sleep problems, positive affect, and craving fits the data well prior to and during quitting. All factor content except somatic symptoms was consistent over time. Correlational analyses indicated that the 5-factor model attenuated construct overlap compared to the implicit model. CONCLUSIONS: The models generated from data-driven approaches (eg, the 5-factor model) reduced overlap and better represented the constructs underlying these measures. This approach created distinct, stable constructs that span over measures of side effects and potential treatment mechanisms. IMPLICATIONS: This study demonstrated that measures assessing treatment mechanisms, withdrawal symptoms, and side effects contain problematic overlap that reduces the clarity of these key constructs. The use of data-driven approaches showed that these measures do not map on to their posited latent constructs (eg, the Minnesota Nicotine Withdrawal Scale does not yield a withdrawal factor). Rather, these measures form distinct, basic processes that may represent more meaningful constructs for future research on cessation and treatment. Assessments designed to individually examine these processes may improve the study of treatment mechanisms.

In search of a chemiluminescence 1,4-dioxy biradical.

Electron paramagnetic resonance spectroscopy has afforded the identification of a much postulated 1,4-dioxy biradical that occurs within the light producing pathway of peroxyoxalate chemiluminescence.

Studies on the mechanism of the peroxyoxalate chemiluminescence reaction: part 2. Further identification of intermediates using 2D EXSY 13C nuclear magnetic resonance spectroscopy.

Further consideration has been given to the reaction pathway of a model peroxyoxalate chemiluminescence system. Again utilising doubly labelled oxalyl chloride and anhydrous hydrogen peroxide, 2D EXSY (13)C nuclear magnetic resonance (NMR) spectroscopy experiments allowed for the characterisation of unknown products and key intermediate species on the dark side of the peroxyoxalate chemiluminescence reaction. Exchange spectroscopy afforded elucidation of a scheme comprised of two distinct mechanistic pathways, one of which contributes to chemiluminescence. (13)C NMR experiments carried out at varied reagent molar ratios demonstrated that excess amounts of hydrogen peroxide favoured formation of 1,2-dioxetanedione: the intermediate that, upon thermolysis, has been long thought to interact with a fluorophore to produce light.