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Purpose: To determine whether different financial incentives are effective in promoting weight loss among prediabetic Medicaid recipients., Design: Four-group, multicenter, randomized clinical trial., Setting and Participants: Medicaid managed care enrollees residing in New York, aged 18 to 64 years, and diagnosed as prediabetic or high risk for diabetes (N = 703)., Intervention: In a 16-week program, participants were randomly assigned to one of 4 arms: (1) control (no incentives), (2) process incentives for attending weekly Diabetes Prevention Program sessions, (3) outcome incentives for achieving weekly weight loss goals, and (4) combined process and outcome incentives., Measures: Weight loss over a 16-week period; proportion who completed educational sessions; proportion who met weight loss goals., Analysis and Results: No intervention arm achieved greater reduction in weight than control (outcome incentive -6.6 lb [-9.1 to -4.1 lb], process incentive -7.3 lb [-9.5 to -5.1 lb], combined incentive -5.8 lb [-8.8 to -2.8 lb], control -7.9 lb [-11.1 to -4.7 lb]; all P > .29). Session attendance in the process incentive arm (50%) was significantly higher than control (31%; P < .0001) and combined incentive arms (28%; P < .0001), but not significantly higher than the outcome incentive arm (38%)., Conclusion: Process incentives increased session attendance, but when combined at half strength with outcome incentives did not achieve that effect. There were no significant effects of either process or outcomes incentives on weight loss.

Purpose: To identify whether financial incentives promote improved disease management in Medicaid recipients diagnosed with hypertension or diabetes, respectively., Design: Four-group, multicenter, randomized clinical trials., Setting and Participants: Between 2013 and 2016, New York State Medicaid managed care members diagnosed with hypertension (N = 920) or with diabetes (N = 959)., Intervention: Participants in each 6-month trial were randomly assigned to 1 of 4 arms: (1) process incentives-earned by attending primary care visits and/or receiving prescription medication refills, (2) outcome incentives-earned by reducing systolic blood pressure (hypertension) or hemoglobin A 1c (HbA 1c ; diabetes) levels, (3) combined process and outcome incentives, and (4) control (no incentives)., Measures: Systolic blood pressure (hypertension) and HbA 1c (diabetes) levels, primary care visits, and medication prescription refills. Analysis and Results: At 6 months, there were no statistically significant differences between intervention arms and the control arm in the change in systolic blood pressure, P = .531. Similarly, there were no significant differences in blood glucose control (HbA 1c ) between the intervention arms and control after 6 months, P = .939. The majority of participants had acceptable systolic blood pressure (<140 mm Hg) or blood glucose (<8.0%) levels at baseline and throughout the study., Conclusion: Financial incentives-regardless of whether they were delivered based on disease-relevant outcomes, process activities, or a combination of the two-have a negligible impact on health outcomes for Medicaid recipients diagnosed with either hypertension or diabetes in 2 studies in which, among other design and operational limitations, the majority of recipients had relatively well-controlled diseases at the time of enrollment.

Objective: The majority of U.S. teens admit to handheld cellphone use while driving, an increasingly common cause of crashes. Attitudes toward novel cellphone applications and settings that block use while driving are poorly understood, potentially limiting uptake. We examined teens' willingness to reduce cellphone use while driving and perceptions of potential strategies to limit this behavior., Methods: Teen drivers (n = 153) aged 16-17 who owned smartphones and admitted to texting while driving completed an online survey. Survey instruments measured willingness to give up cellphone use and perceptions of technological and behavioral economic strategies to reduce cellphone use while driving. We used chi-square tests to test the hypothesis that willingness to give up certain types of cellphone use while driving and the perceptions of strategies to reduce cellphone use while driving would differ by self-reported frequency of texting while driving in the past 30 days (low [1-5 days] vs. high [6 or more days])., Results: Most teens were willing or somewhat willing to give up reading texts (90%), sending texts (95%), and social media (99%) while driving. However, they were not willing to give up navigation (59%) and music applications (43%). Those who engaged in high-frequency texting while driving were more likely to say that they were not willing to give up navigation applications (73 vs. 44%, P <.001), music applications (54 vs. 32%, P <.001), and reading texts (15 vs. 4%, P =.029). Overall, the following strategies where rated as likely to be very effective for reducing texting while driving: gain-framed financial incentives (75%), loss-framed financial incentives (63%), group-based financial incentives (58%), insurance discounts (53%), automatic phone locking while driving (54%), e-mail notifications to parents (47%), automated responses to incoming texts (42%), peer concern (18%), and parental concern (15%). Those who engaged in high-frequency texting while driving were less likely to say that following strategies would be very effective: automated responses to incoming texts (33 vs. 53%, P =.016), peer concern (9 vs. 29%, P =.002), and parental concern (9 vs. 22%, P =.025). The strongest perceived benefit of cellphone blocking apps was decreasing distraction (86%). The predominant reason for not wanting to use this technology was not wanting parents to monitor their behavior (60%)., Conclusions: Promising strategies for increasing acceptance of cellphone blocking technology among teen drivers include automated screen locking and permitting hands-free navigation and music combined with behavioral economic incentives to sustain engagement.

Background: Prescription opioid (PO) abuse has become an urgent public health issue in the United States. Detoxification is one important treatment option, yet relatively little is known about the time course and severity of opioid withdrawal during buprenorphine detoxification., Methods: This is a secondary analysis of data from a randomized, placebo-controlled, double-blind evaluation of 1, 2, and 4-week outpatient buprenorphine tapers among primary prescription opioid (PO) abusers. The aim is to characterize the time course and severity of buprenorphine withdrawal under rigorous, double-blind conditions, across multiple taper durations, and using multiple withdrawal-related measures (i.e., self-report and observer ratings, pupil diameter, ancillary medication utilization). Participants were PO-dependent adults undergoing buprenorphine detoxification and biochemically-verified to be continuously abstinent from opioids during their taper (N = 28)., Results: Participants randomly assigned to the 4-week taper regimen experienced a relatively mild and stable course of withdrawal, with few peaks in severity. In contrast, the 1- and 2-week taper groups experienced stark increases in withdrawal severity during the week following the last buprenorphine dose, followed by declines in withdrawal severity thereafter. The 4-week taper group also reported significantly fewer disruptions in sleep compared to the other experimental groups. When predictors of withdrawal were examined, baseline ratings of "Expected Withdrawal Severity" was the most robust predictor of withdrawal experienced during the taper., Conclusion: Data from this trial may inform clinicians about the expected time course, magnitude, and pattern of buprenorphine withdrawal and aid efforts to identify patients who may need additional clinical support during outpatient buprenorphine detoxification., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Background: Determination of comparative effectiveness in a randomized controlled trial requires consideration of an intervention's comparative uptake (or acceptance) among randomized participants and the intervention's comparative efficacy among participants who use their assigned intervention. If acceptance differs across interventions, then simple randomization of participants can result in post-randomization losses that introduce bias and limit statistical power., Methods: We develop a novel preference-adaptive randomization procedure in which the allocation probabilities are updated based on the inverse of the relative acceptance rates among randomized participants in each arm. In simulation studies, we determine the optimal frequency with which to update the allocation probabilities based on the number of participants randomized. We illustrate the development and application of preference-adaptive randomization using a randomized controlled trial comparing the effectiveness of different financial incentive structures on prolonged smoking cessation., Results: Simulation studies indicated that preference-adaptive randomization performed best with frequent updating, accommodated differences in acceptance across arms, and performed well even if the initial values for the allocation probabilities were not equal to their true values. Updating the allocation probabilities after randomizing each participant minimized imbalances in the number of accepting participants across arms over time. In the smoking cessation trial, unexpectedly large differences in acceptance among arms required us to limit the allocation of participants to less acceptable interventions. Nonetheless, the procedure achieved equal numbers of accepting participants in the more acceptable arms, and balanced the characteristics of participants across assigned interventions., Conclusions: Preference-adaptive randomization, coupled with analysis methods based on instrumental variables, can enhance the validity and generalizability of comparative effectiveness studies. In particular, preference-adaptive randomization augments statistical power by maintaining balanced sample sizes in efficacy analyses, while retaining the ability of randomization to balance covariates across arms in effectiveness analyses., Trial Registration: ClinicalTrials.gov, NCT01526265; 31 January 2012.

Background: The high rates of HIV and Hepatitis C (HCV) infection among opioid abusers is a serious public health problem, and efforts to enhance knowledge regarding risks for HIV/hepatitis infection in this population are important. Abuse of prescription opioids (POs), in particular, has increased substantially in the past decade and is associated with increasing rates of injection drug use and HCV infection., Methods: This study describes the effects of a brief HIV/HCV educational intervention delivered in the context of a larger randomized, double-blind clinical trial evaluating the relative efficacy of 1-, 2-, and 4-week outpatient buprenorphine tapers and subsequent oral naltrexone maintenance for treating PO dependence. HIV- and HCV-related knowledge and risk behaviors were characterized pre- and post-intervention in 54 primary PO abusers., Results: The educational intervention was associated with significant improvements in HIV (p<.001) and HCV (p<.001) knowledge. Significant improvements (p<.001) were observed on all three domains of the HIV questionnaire (i.e., general knowledge, sexual risk behaviors, drug risk behaviors) and on 21 and 11 individual items on the HIV and HCV questionnaires, respectively. Self-reported likelihood of using a condom also increased significantly (p<.05) from pre- to post-intervention. No additional changes in self-reported risk behaviors were observed., Conclusion: These results suggest that a brief, easy-to-administer intervention is associated with substantial gains in HIV and HCV knowledge among PO abusers and represents the necessary first step toward the dissemination of a structured prevention HIV and HCV intervention for PO abusers., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

In September 2011 the Centers for Medicare and Medicaid Services awarded $85 million in grants to ten states to test financial incentive programs to encourage healthy behavior among Medicaid enrollees with chronic diseases. There is little published evidence about the effectiveness of such incentives within the Medicaid program. We evaluated the available research from three earlier Medicaid incentive programs and found mixed results. On the one hand, in Florida only about half of the $41.3 million in available credits was "claimed" by enrollees between 2006 and 2011. On the other, Idaho's incentive program was credited with improving the proportion of children who were up-to-date on well-child visits. Our findings suggest that Medicaid incentive programs should be designed so that enrollees can understand them and so that the incentives are attractive enough to motivate participation. Medicaid incentive programs also should be subject to rigorous evaluation to more clearly establish their effectiveness.

Two different and generally noncomplimentary disruptions of timing by pharmacological agents have been found. One is a lateral shift of the psychophysical curve for time, indicating a subjective shortening or lengthening of time, whereas the other is a flattening of the curve and decrease in temporal accuracy. This study assessed the role of a methodological variation in producing this discrepancy. The procedure used required pigeons to classify stimulus duration intervals as short or long, using response alternatives that were defined either by the location of response keys (spatial), or by their color (nonspatial). D-amphetamine was used to replicate earlier findings, whereas nicotine and haloperidol extended the research to different drug classes. Dose-dependent decreases in the accuracy of classifying temporal intervals and a flattening of the psychophysical curve were found across drug classes for both spatial and nonspatial procedural variations. Procedural variations, under these conditions, could not explain the discrepancy. However, the results from this study added to the mounting body of literature showing decrements in temporal accuracy and a flattening of the psychophysical curve because of a number of diverse pharmacological and nonpharmacological disruptors.

Cigarette smoking is highly prevalent among patients who are being treated for opioid-dependence, yet there have been limited scientific efforts to promote smoking cessation in this population. Contingency management (CM) is a behavioral treatment that provides monetary incentives contingent upon biochemical evidence of drug abstinence. This paper discusses the results of two studies that utilized CM to promote brief smoking cessation among opioid-maintained patients. Participants in a pilot study were randomly assigned for a 2-week period to a Contingent group that earned monetary vouchers for providing biochemical samples that met criteria for smoking abstinence, or a Noncontingent group that earned monetary vouchers independent of smoking status (Dunn et al., 2008). Results showed Contingent participants provided significantly more smoking-negative samples than Noncontingent participants (55% vs. 5%, respectively). A second randomized trial that utilized the same 2-week intervention and provided access to the smoking cessation pharmacotherapy bupropion replicated the results of the pilot study (55% and 17% abstinence in Contingent and Noncontingent groups, respectively; Dunn et al, 2010). Relapse to illicit drug use was also evaluated prospectively and no association between smoking abstinence and relapse to illicit drug use was observed (Dunn et al., 2009). It will be important for future studies to evaluate participant characteristics that might predict better treatment outcome, to assess the contribution that pharmacotherapies might have alone or in combination with a CM intervention on smoking cessation and to evaluate methods for maintaining the abstinence that is achieved during this brief intervention for longer periods of time., ((c) 2011 APA, all rights reserved)

Previous reports using stimulus intensity changes to disrupt temporal discrimination have shown shifts in the psychophysical curve for time, while studies using other disruptors have shown a flattening of the curve. The current study investigated the impact of increases and decreases in stimulus intensity on temporal discrimination in pigeons, to determine if a flattening of the curve could be extended to this disruptor. The brightness of the sample to be timed was manipulated under two procedural variations, in which the response alternatives were differentiated by color or location. Results showed that all subjects in the color procedure, and one in the location procedure, showed a flattening of the psychophysical curve when they experienced increased stimulus intensity in descending order. No subjects exposed to an ascending order of stimulus intensities, and none of the other subjects in the location procedure, showed any impact of changed stimulus intensity. Minimal disruption was found when test sessions presented decreased stimulus intensity levels in a second series. These results, together with those using other types of disruptors, add to the evidence of a flattening of the psychophysical curve when temporal discrimination is disrupted.

The impact of two procedural variants of the matching to sample of duration procedure on the effects of chronically administered D-amphetamine on temporal discrimination was assessed. The task consisted of subjects classifying durations as short or long to produce a psychophysical curve for time. Procedural variations included response alternatives being defined by either the location of the response keys (Location), or by their color (Color). During Phase 1, two groups of pigeons experienced one of these procedures while being administered with D-amphetamine in an ABA chronic dosing regimen. Phase 2 was a reversal condition in which select birds from Phase 1 were trained on the other procedural variation that they had not experienced and were again given D-amphetamine in an ABA chronic regimen. Results showed that during Phase 1, subjects in the Color group showed a flattening of the psychophysical curves during amphetamine administration, whereas those in the Location group showed a shift of the psychophysical curve to the left and right. Phase 2 revealed that subjects who had experienced the Location variant first were less disrupted by the drug, even when experiencing the Color condition. The procedural variation, dosing regimen, and form of data analysis all provide more information regarding the cause of discrepancies in the timing literature regarding differential effects of D-amphetamine on timing behavior.

This study assessed temporal discrimination using a procedure in which pigeons classified temporal intervals as short or long based on different responses following visually presented stimulus durations. For the Location group, response alternatives were defined by the location of response keys, whereas for the Color group response alternatives were defined by key color. Temporal parameters were derived from psychophysical curves for time, and the impact of d-amphetamine was determined during acute and chronic dosing. Results showed that classification of temporal intervals was disrupted dose dependently during the acute drug assessment, regardless of the procedural variation. During the chronic drug assessment, differences in one of the psychophysical parameters, Range, were found between groups, as well as a significant effect of Dose on Standard Deviation values in the Color group. These data suggest that procedural variation does not lead to differential effects of d-amphetamine when administered in an acute regimen; however, differences found during chronic administration suggest that procedural variations may influence the development of tolerance as evidenced by differing Range values between groups and marked disruption of Standard Deviation values at the low dose in the Color group. The influence exerted on temporal behavior and tolerance by procedural variations during acute and chronic regimens of d-amphetamine should be explored further.

When pharmacological and non-pharmacological agents are used to disrupt temporal discrimination, two major findings have emerged in the literature. One result reveals lateral shifts of the psychophysical curve for time due to disruptors, while the other is a decrease in accuracy for classifying short and long intervals and a flattening of the psychophysical curve. These results represent a discrepancy within the timing literature that requires clarification. The current study determined the effects of pre-feed, increased density of reinforcement during session, and extinction on the Location variation of a temporal discrimination procedure. The results showed that extinction and pre-feed (at higher levels), when presented in an acute fashion, led to right-ward shifts in the psychophysical curve. Our results, when compared to similar studies in the literature, suggest that lateral shifts are more likely to be found due to disruptors when the Location variation is being used and when procedures are less complicated.

A multiple differential reinforcement of low rate 8 s discrete-trial, differential reinforcement of low rate 8 s free-operant procedure was used to investigate the effects of D-amphetamine on interval timing in pigeons. On the discrete trial differential reinforcement of low rate early responses terminated the trial; on the free-operant differential reinforcement of low rate early responses reset the reinforcement timer but had no other effects. Frequency distributions of log interevent times for responses following reinforcement on both the free-operant and discrete-trial components showed a single-peaked distribution. The interevent time distribution for responses preceded by unreinforced responses on the free-operant differential reinforcement of low rate showed two peaks. The pigeons were administered two doses of D-amphetamine for 20 successive sessions. The means of interevent time distributions did not change under drug for either condition but widths of the distributions increased in both conditions and for both types of interevent times in the free-operant differential reinforcement of low rate. In the free-operant condition the mean interevent time for responses preceded by prior responses declined significantly with drug owing to a reduction in the proportion of responses in the shorter interevent time distribution. In effect, response bouts were shortened by drug administration. The rate-dependent hypothesis well described the effect of amphetamine on responses in the free-operant procedure. These results are discussed in the context of amphetamine's effects on the temporal structure of behavior.

The effects of d-amphetamine on pigeons' key-pecking under the peak interval (PI) procedure were investigated in two experiments. In experiment I the effects of doses of d-amphetamine from 0.75 to 3.0 mg/kg on responding under PI 30 and 45 s were studied for 10 successive days. Reductions in peak time and wait time were observed at both PI values and an increase in the width was found at PI 30 s. There was no evidence of tolerance. In experiment II, pigeons exposed to a PI 45 s schedule were administered doses of D-amphetamine of 1.5 and 3.0 mg/kg for 30 successive days. Reductions in peak time and wait time were found here. Evidence of tolerance was found in wait time, peak time and width of the distribution at the higher dose. In both experiments a rate-dependent effect of the drug was found in the portion of each peak trial before the time that food was delivered on reinforced trials; this effect was weaker after the customary time of food delivery. The rate-dependent effect for responses before food time, combined with little effect of the drug on responses after food time, is shown by simulation to be sufficient to account for the reduction in peak time, without the need to appeal to an internal clock mechanism.

Two experiments used a matching to sample of durations procedure to examine changes in temporal discrimination evoked by D-amphetamine (0.75, 1.50, 2.25 and 3.0 mg/kg i.m.) in pigeons. Responses to one key color were reinforced after long (8-s) stimuli: responses to the alternative key color were reinforced after short (2-s) stimuli. Stimuli of intermediate duration were reinforced in Experiment 1 and were not reinforced in Experiment 2. Sigmoid functions relating percent of choices of the key reinforced after long-duration stimuli to the duration of stimulus presented were fit by a cumulative normal function. In addition to a parameter giving the left/right position of the sigmoid curves (which indexes temporal perception), this function also provided estimates of the range and slope of the curve (measures of stimulus control). The results showed that, contrary to many published reports, amphetamine had no effect on the left/right positioning of the sigmoid curve. There was, however, an effect of amphetamine on stimulus control, as shown by the general flattening of the psychophysical functions. Little evidence of tolerance to the drug's behavioral effects was found after 30 consecutive days of behavioral testing under amphetamine.