human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Although treatment outcome in prize-based contingency management has been shown to depend on reinforcement schedule , the optimal schedule is still unknown . Therefore , we conducted a retrospective analysis of data from a r and omized clinical trial ( Ghitza et al. , 2007 ) to determine the effects of the probability of winning a prize  ( low vs. high ) and the size of the prize won ( small , large , or jumbo ) on likelihood of abstinence until the next urine- collection day for heroin and cocaine users ( N=116 ) in methadone maintenance . Higher probability of winning , but not the size of individual prizes , was associated with a greater percentage of cocaine-negative , but not opiate-negative , urines BACKGROUND Smoking is the leading preventable cause of premature death in the United States . Previous studies of financial incentives for smoking cessation in work setting s have not shown that such incentives have significant effects on cessation rates , but these studies have had limited power , and the incentives used may have been insufficient . METHODS We r and omly assigned 878 employees of a multinational company based in the United States to receive information about smoking-cessation programs ( 442 employees ) or to receive information about programs plus financial incentives ( 436 employees ) . The financial incentives were $ 100 for completion of a smoking-cessation program , $ 250 for cessation of smoking within 6 months after study enrollment , as confirmed by a biochemical test , and $ 400 for abstinence for an additional 6 months after the initial cessation , as confirmed by a biochemical test . Individual participants were stratified according to work site , heavy or nonheavy smoking , and income . The primary end point was smoking cessation 9 or 12 months after enrollment , depending on whether initial cessation was reported at 3 or 6 months . Secondary end points were smoking cessation within the first 6 months after enrollment and rates of participation in and completion of smoking-cessation programs . RESULTS The incentive group had significantly higher rates of smoking cessation than did the information-only group 9 or 12 months after enrollment ( 14.7 % vs. 5.0 % , P<0.001 ) and 15 or 18 months after enrollment ( 9.4 % vs. 3.6 % , P<0.001 ) . Incentive-group participants also had significantly higher rates of enrollment in a smoking-cessation program ( 15.4 % vs. 5.4 % , P<0.001 ) , completion of a smoking-cessation program ( 10.8 % vs. 2.5 % , P<0.001 ) , and smoking cessation within the first 6 months after enrollment ( 20.9 % vs. 11.8 % , P<0.001 ) . CONCLUSIONS In this study of employees of one large company , financial incentives for smoking cessation significantly increased the rates of smoking cessation . ( Clinical Trials.gov number , NCT00128375 . AIMS This study examined whether voucher-based reinforcement therapy ( VBRT ) contingent upon smoking abstinence during pregnancy is an effective method for decreasing  maternal smoking during pregnancy and improving fetal growth . DESIGN , SETTING AND PARTICIPANTS A two-condition , parallel-groups , r and omized controlled trial was conducted in a university-based research clinic . A total of 82 smokers entering prenatal care participated in the trial . INTERVENTION Participants were assigned r and omly to either contingent or non-contingent voucher conditions . Vouchers exchangeable for retail items were available during pregnancy and for 12 weeks postpartum . In the contingent condition , vouchers were earned for biochemically verified smoking abstinence ; in the non-contingent condition , vouchers were earned independent of smoking status . MEASUREMENTS Smoking outcomes were evaluated using urine-toxicology testing and self-report . Fetal growth outcomes were evaluated using serial ultrasound examinations performed during the third trimester . FINDINGS Contingent vouchers significantly increased point-prevalence abstinence at the end-of-pregnancy ( 41 % versus 10 % ) and at the 12-week postpartum assessment ( 24 % versus 3 % ) . Serial ultrasound examinations indicated significantly greater growth in terms of estimated fetal weight , femur length and abdominal circumference in the contingent compared to the non-contingent conditions . CONCLUSIONS These results provide further evidence that VBRT has a substantive contribution to make to efforts to decrease maternal smoking during pregnancy and provide new evidence of positive effects on fetal health BACKGROUND Many governments have implemented conditional cash transfer ( CCT ) programmes with the goal of improving options for poor families through interventions in health , nutrition , and education . Families enrolled in CCT programmes  receive cash in exchange for complying with certain conditions : preventive health requirements and nutrition supplementation , education , and monitoring design ed to improve health outcomes and promote positive behaviour change . Our aim was to disaggregate the effects of cash transfer from those of other programme components . METHODS In an intervention that began in 1998 in Mexico , low-income communities ( n=506 ) were r and omly assigned to be enrolled in a CCT programme  ( Oportunidades , formerly Progresa ) immediately or 18 months later . In 2003 , children ( n=2449 ) aged 24 - 68 months who had been enrolled in the programme their entire lives were assessed for a wide variety of outcomes . We used linear and logistic regression to determine the effect size for each outcome that is associated with a doubling of cash transfers while controlling for a wide range of covariates , including measures of household socioeconomic status . FINDINGS A doubling of cash transfers was associated with higher height-for-age Z score ( beta 0.20 , 95 % CI 0.09 - 0.30 ; p<0.0001 ) , lower prevalence of stunting ( -0.10 , -0.16 to -0.05 ; p<0.0001 ) , lower body-mass index for age percentile ( -2.85 , -5.54 to -0.15 ; p=0.04 ) , and lower prevalence of being overweight ( -0.08 , -0.13 to -0.03 ; p=0.001 ) . A doubling of cash transfers was also associated with children doing better on a scale of motor development , three scales of cognitive development , and with receptive language . INTERPRETATION Our results suggest that the cash transfer component of Oportunidades is associated with better outcomes in child health , growth , and development BACKGROUND Relapse to drug use is often seen when contingencies design ed to reduce drug use are discontinued . This paper reports on a stepdown maintenance contingency and 1-year follow-up in 110 patients who were maintained on methadone ( 50 or 70 mg/day ) and who had completed a contingency management trial targeted to decreasing their opiate use . In the prior study ( induction phase , 8 weeks ) participants received vouchers for each opiate-negative urine screen or noncontingently . METHODS In this study ( maintenance phase , 12 weeks ) , participants were rer and omized to receive vouchers and take-home methadone doses contingent on providing opiate-negative urine specimens ( N=55 ) or noncontingently ( N=55 ) . Since participants had been rer and omized from induction-phase contingencies , most study data were analyzed as if from a 2 x 2 ( inductionxmaintenance ) design . Follow-up interviews were conducted at 3 , 6 , and 12 months after study participation . RESULTS Patients who received the maintenance contingency following an 8-week induction contingency had better outcomes than those who received noncontingent incentives in either the maintenance or induction phases of the trial . Good outcome at follow-up was predicted by enrollment in methadone maintenance after the study . Significantly more participants in the maintenance contingency group transferred directly to another methadone program . CONCLUSION These findings support the therapeutic value of extending the duration of contingency management and long-term methadone maintenance This study 's goals were to characterize the relationship between early and longer term cocaine abstinence and assess whether increasing early abstinence increases longer term abstinence . Results from 190 cocaine-dependent out patients were analyzed . Participants were divided into 2 conditions : ( a ) those treated with community reinforcement approach ( CRA ) plus contingent vouchers ( n = 125 ) and ( b ) those treated with control treatments ( n = 65 ) . A period of sustained abstinence during treatment was associated with significantly greater odds of posttreatment abstinence , with no evidence of differences between the 2 treatment conditions in that regard . Treatment conditions differed in that CRA plus contingent vouchers increased the proportion of participants who sustained a period of during-treatment abstinence and increased abstinence during 6-month posttreatment follow-up . Devising interventions that increase the proportion of individuals who achieve an early period of sustained abstinence may be key to increasing longer term cocaine abstinence We report results from a pilot study examining the use of vouchers redeemable for retail items as incentives for smoking cessation during pregnancy and postpartum . Of 100 study -eligible women who were still smoking upon entering prenatal care , 58 were recruited from university-based and community obstetric practice s to participate in a smoking cessation study . Participants were assigned to either contingent or noncontingent voucher conditions . Vouchers were available during pregnancy and for 12 weeks postpartum . In the contingent condition , vouchers were earned for biochemically verified smoking abstinence . In the noncontingent condition , vouchers were earned independent of smoking status . Abstinence monitoring and associated voucher delivery was conducted daily during the initial 5 days of the cessation effort , gradually decreased to every other week antepartum , increased to once weekly during the initial 4 weeks postpartum , and then decreased again to every other week for the remaining 8 weeks of the postpartum intervention period . Contingent vouchers increased 7-day point-prevalence abstinence at the end-of-pregnancy ( 37 % vs. 9 % ) and 12-week postpartum ( 33 % vs. 0 % ) assessment s. That effect was sustained through the 24-week postpartum assessment ( 27 % vs. 0 % ) , which was 12 weeks after discontinuation of the voucher program . Total mean voucher earnings across antepartum and postpartum were 397 US dollars ( SD=414 US dollars ) and 313 US dollars ( SD=142 dollars ) in the contingent and noncontingent conditions , respectively . The magnitude of these treatment effects exceed levels typically observed with pregnant and recently postpartum smokers , and the maintenance of effects through 24 weeks postpartum extends the duration beyond those reported previously OBJECTIVES This study assessed the independent and combined effects of different levels of monetary incentives and a theory-based educational intervention on return for tuberculosis ( TB ) skin test reading in a sample of active injection drug and crack cocaine users . Prevalence of TB infection in this sample was also determined . METHODS Active or recent drug users ( n = 1004 ) , recruited via street outreach techniques , were skin tested for TB . They were r and omly assigned to 1 of 2 levels of monetary incentive ( $ 5 and $ 10 ) provided at return for skin test reading , alone or in combination with a brief motivational education session . RESULTS More than 90 % of those who received $ 10 returned for skin test reading , in comparison with 85 % of those who received $ 5 and 33 % of those who received no monetary incentive . The education session had no impact on return for skin test reading . The prevalence of a positive tuberculin test was 18.3 % . CONCLUSIONS Monetary incentives dramatically increase the return rate for TB skin test reading among drug users who are at high risk of TB infection CONTEXT Identifying effective obesity treatment is both a clinical challenge and a public health priority due to the health consequences of obesity . OBJECTIVE To determine whether common decision errors identified by behavioral economists such as prospect theory , loss aversion , and regret could be used to design an effective weight loss intervention . DESIGN , SETTING , AND PARTICIPANTS Fifty-seven healthy participants aged 30 - 70 years with a body mass index of 30 - 40 were r and omized to 3 weight loss plans : monthly weigh-ins , a lottery incentive program , or a deposit contract that allowed for participant matching , with a weight loss goal of 1 lb ( 0.45 kg ) a week for 16 weeks . Participants were recruited May-August 2007 at the Philadelphia VA Medical Center in Pennsylvania and were followed up through June 2008 . MAIN OUTCOME MEASURES Weight loss after 16 weeks . RESULTS The incentive groups  lost significantly more weight than the control group ( mean , 3.9 lb ) . Compared with the control group , the lottery group lost a mean of 13.1 lb ( 95 % confidence interval [ CI ] of the difference in means , 1.95 - 16.40 ; P = .02 ) and the deposit contract group lost a mean of 14.0 lb ( 95 % CI of the difference in means , 3.69 - 16.43 ; P = .006 ) . About half of those in both incentive groups met the 16-lb target weight loss : 47.4 % ( 95 % CI , 24.5%-71.1 % ) in 
    Output:
    
agent
Results Current evidence indicates that incentives can be effective in driving health behaviour change under certain provisos , while a number of misgivings continue to be deliberated on .
Conclusion These key principles can assist policy makers in making decisions on the use of financial incentives directed at achieving improvements in public health
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Although treatment outcome in prize-based contingency management has been shown to depend on reinforcement schedule , the optimal schedule is still unknown . Therefore , we conducted a retrospective analysis of data from a r and omized clinical trial ( Ghitza et al. , 2007 ) to determine the effects of the probability of winning a prize  ( low vs. high ) and the size of the prize won ( small , large , or jumbo ) on likelihood of abstinence until the next urine- collection day for heroin and cocaine users ( N=116 ) in methadone maintenance . Higher probability of winning , but not the size of individual prizes , was associated with a greater percentage of cocaine-negative , but not opiate-negative , urines BACKGROUND Smoking is the leading preventable cause of premature death in the United States . Previous studies of financial incentives for smoking cessation in work setting s have not shown that such incentives have significant effects on cessation rates , but these studies have had limited power , and the incentives used may have been insufficient . METHODS We r and omly assigned 878 employees of a multinational company based in the United States to receive information about smoking-cessation programs ( 442 employees ) or to receive information about programs plus financial incentives ( 436 employees ) . The financial incentives were $ 100 for completion of a smoking-cessation program , $ 250 for cessation of smoking within 6 months after study enrollment , as confirmed by a biochemical test , and $ 400 for abstinence for an additional 6 months after the initial cessation , as confirmed by a biochemical test . Individual participants were stratified according to work site , heavy or nonheavy smoking , and income . The primary end point was smoking cessation 9 or 12 months after enrollment , depending on whether initial cessation was reported at 3 or 6 months . Secondary end points were smoking cessation within the first 6 months after enrollment and rates of participation in and completion of smoking-cessation programs . RESULTS The incentive group had significantly higher rates of smoking cessation than did the information-only group 9 or 12 months after enrollment ( 14.7 % vs. 5.0 % , P<0.001 ) and 15 or 18 months after enrollment ( 9.4 % vs. 3.6 % , P<0.001 ) . Incentive-group participants also had significantly higher rates of enrollment in a smoking-cessation program ( 15.4 % vs. 5.4 % , P<0.001 ) , completion of a smoking-cessation program ( 10.8 % vs. 2.5 % , P<0.001 ) , and smoking cessation within the first 6 months after enrollment ( 20.9 % vs. 11.8 % , P<0.001 ) . CONCLUSIONS In this study of employees of one large company , financial incentives for smoking cessation significantly increased the rates of smoking cessation . ( Clinical Trials.gov number , NCT00128375 . AIMS This study examined whether voucher-based reinforcement therapy ( VBRT ) contingent upon smoking abstinence during pregnancy is an effective method for decreasing  maternal smoking during pregnancy and improving fetal growth . DESIGN , SETTING AND PARTICIPANTS A two-condition , parallel-groups , r and omized controlled trial was conducted in a university-based research clinic . A total of 82 smokers entering prenatal care participated in the trial . INTERVENTION Participants were assigned r and omly to either contingent or non-contingent voucher conditions . Vouchers exchangeable for retail items were available during pregnancy and for 12 weeks postpartum . In the contingent condition , vouchers were earned for biochemically verified smoking abstinence ; in the non-contingent condition , vouchers were earned independent of smoking status . MEASUREMENTS Smoking outcomes were evaluated using urine-toxicology testing and self-report . Fetal growth outcomes were evaluated using serial ultrasound examinations performed during the third trimester . FINDINGS Contingent vouchers significantly increased point-prevalence abstinence at the end-of-pregnancy ( 41 % versus 10 % ) and at the 12-week postpartum assessment ( 24 % versus 3 % ) . Serial ultrasound examinations indicated significantly greater growth in terms of estimated fetal weight , femur length and abdominal circumference in the contingent compared to the non-contingent conditions . CONCLUSIONS These results provide further evidence that VBRT has a substantive contribution to make to efforts to decrease maternal smoking during pregnancy and provide new evidence of positive effects on fetal health BACKGROUND Many governments have implemented conditional cash transfer ( CCT ) programmes with the goal of improving options for poor families through interventions in health , nutrition , and education . Families enrolled in CCT programmes  receive cash in exchange for complying with certain conditions : preventive health requirements and nutrition supplementation , education , and monitoring design ed to improve health outcomes and promote positive behaviour change . Our aim was to disaggregate the effects of cash transfer from those of other programme components . METHODS In an intervention that began in 1998 in Mexico , low-income communities ( n=506 ) were r and omly assigned to be enrolled in a CCT programme  ( Oportunidades , formerly Progresa ) immediately or 18 months later . In 2003 , children ( n=2449 ) aged 24 - 68 months who had been enrolled in the programme their entire lives were assessed for a wide variety of outcomes . We used linear and logistic regression to determine the effect size for each outcome that is associated with a doubling of cash transfers while controlling for a wide range of covariates , including measures of household socioeconomic status . FINDINGS A doubling of cash transfers was associated with higher height-for-age Z score ( beta 0.20 , 95 % CI 0.09 - 0.30 ; p<0.0001 ) , lower prevalence of stunting ( -0.10 , -0.16 to -0.05 ; p<0.0001 ) , lower body-mass index for age percentile ( -2.85 , -5.54 to -0.15 ; p=0.04 ) , and lower prevalence of being overweight ( -0.08 , -0.13 to -0.03 ; p=0.001 ) . A doubling of cash transfers was also associated with children doing better on a scale of motor development , three scales of cognitive development , and with receptive language . INTERPRETATION Our results suggest that the cash transfer component of Oportunidades is associated with better outcomes in child health , growth , and development BACKGROUND Relapse to drug use is often seen when contingencies design ed to reduce drug use are discontinued . This paper reports on a stepdown maintenance contingency and 1-year follow-up in 110 patients who were maintained on methadone ( 50 or 70 mg/day ) and who had completed a contingency management trial targeted to decreasing their opiate use . In the prior study ( induction phase , 8 weeks ) participants received vouchers for each opiate-negative urine screen or noncontingently . METHODS In this study ( maintenance phase , 12 weeks ) , participants were rer and omized to receive vouchers and take-home methadone doses contingent on providing opiate-negative urine specimens ( N=55 ) or noncontingently ( N=55 ) . Since participants had been rer and omized from induction-phase contingencies , most study data were analyzed as if from a 2 x 2 ( inductionxmaintenance ) design . Follow-up interviews were conducted at 3 , 6 , and 12 months after study participation . RESULTS Patients who received the maintenance contingency following an 8-week induction contingency had better outcomes than those who received noncontingent incentives in either the maintenance or induction phases of the trial . Good outcome at follow-up was predicted by enrollment in methadone maintenance after the study . Significantly more participants in the maintenance contingency group transferred directly to another methadone program . CONCLUSION These findings support the therapeutic value of extending the duration of contingency management and long-term methadone maintenance This study 's goals were to characterize the relationship between early and longer term cocaine abstinence and assess whether increasing early abstinence increases longer term abstinence . Results from 190 cocaine-dependent out patients were analyzed . Participants were divided into 2 conditions : ( a ) those treated with community reinforcement approach ( CRA ) plus contingent vouchers ( n = 125 ) and ( b ) those treated with control treatments ( n = 65 ) . A period of sustained abstinence during treatment was associated with significantly greater odds of posttreatment abstinence , with no evidence of differences between the 2 treatment conditions in that regard . Treatment conditions differed in that CRA plus contingent vouchers increased the proportion of participants who sustained a period of during-treatment abstinence and increased abstinence during 6-month posttreatment follow-up . Devising interventions that increase the proportion of individuals who achieve an early period of sustained abstinence may be key to increasing longer term cocaine abstinence We report results from a pilot study examining the use of vouchers redeemable for retail items as incentives for smoking cessation during pregnancy and postpartum . Of 100 study -eligible women who were still smoking upon entering prenatal care , 58 were recruited from university-based and community obstetric practice s to participate in a smoking cessation study . Participants were assigned to either contingent or noncontingent voucher conditions . Vouchers were available during pregnancy and for 12 weeks postpartum . In the contingent condition , vouchers were earned for biochemically verified smoking abstinence . In the noncontingent condition , vouchers were earned independent of smoking status . Abstinence monitoring and associated voucher delivery was conducted daily during the initial 5 days of the cessation effort , gradually decreased to every other week antepartum , increased to once weekly during the initial 4 weeks postpartum , and then decreased again to every other week for the remaining 8 weeks of the postpartum intervention period . Contingent vouchers increased 7-day point-prevalence abstinence at the end-of-pregnancy ( 37 % vs. 9 % ) and 12-week postpartum ( 33 % vs. 0 % ) assessment s. That effect was sustained through the 24-week postpartum assessment ( 27 % vs. 0 % ) , which was 12 weeks after discontinuation of the voucher program . Total mean voucher earnings across antepartum and postpartum were 397 US dollars ( SD=414 US dollars ) and 313 US dollars ( SD=142 dollars ) in the contingent and noncontingent conditions , respectively . The magnitude of these treatment effects exceed levels typically observed with pregnant and recently postpartum smokers , and the maintenance of effects through 24 weeks postpartum extends the duration beyond those reported previously OBJECTIVES This study assessed the independent and combined effects of different levels of monetary incentives and a theory-based educational intervention on return for tuberculosis ( TB ) skin test reading in a sample of active injection drug and crack cocaine users . Prevalence of TB infection in this sample was also determined . METHODS Active or recent drug users ( n = 1004 ) , recruited via street outreach techniques , were skin tested for TB . They were r and omly assigned to 1 of 2 levels of monetary incentive ( $ 5 and $ 10 ) provided at return for skin test reading , alone or in combination with a brief motivational education session . RESULTS More than 90 % of those who received $ 10 returned for skin test reading , in comparison with 85 % of those who received $ 5 and 33 % of those who received no monetary incentive . The education session had no impact on return for skin test reading . The prevalence of a positive tuberculin test was 18.3 % . CONCLUSIONS Monetary incentives dramatically increase the return rate for TB skin test reading among drug users who are at high risk of TB infection CONTEXT Identifying effective obesity treatment is both a clinical challenge and a public health priority due to the health consequences of obesity . OBJECTIVE To determine whether common decision errors identified by behavioral economists such as prospect theory , loss aversion , and regret could be used to design an effective weight loss intervention . DESIGN , SETTING , AND PARTICIPANTS Fifty-seven healthy participants aged 30 - 70 years with a body mass index of 30 - 40 were r and omized to 3 weight loss plans : monthly weigh-ins , a lottery incentive program , or a deposit contract that allowed for participant matching , with a weight loss goal of 1 lb ( 0.45 kg ) a week for 16 weeks . Participants were recruited May-August 2007 at the Philadelphia VA Medical Center in Pennsylvania and were followed up through June 2008 . MAIN OUTCOME MEASURES Weight loss after 16 weeks . RESULTS The incentive groups  lost significantly more weight than the control group ( mean , 3.9 lb ) . Compared with the control group , the lottery group lost a mean of 13.1 lb ( 95 % confidence interval [ CI ] of the difference in means , 1.95 - 16.40 ; P = .02 ) and the deposit contract group lost a mean of 14.0 lb ( 95 % CI of the difference in means , 3.69 - 16.43 ; P = .006 ) . About half of those in both incentive groups met the 16-lb target weight loss : 47.4 % ( 95 % CI , 24.5%-71.1 % ) in 
    Output:
    