***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: The need for effective , low-cost self-help treatment methods for  smokeless tobacco ( ST ) addiction  becomes more evident as rates of product use and associated morbidities increase . This study evaluated two self-help methods for ST cessation .  One hundred ninety-eight ST users were r and omized into two conditions : half received the LifeSign , a credit card-sized computer design ed for gradual ST cessation , and half received the Enough Snuff self-help manual and a video . Subjects in both conditions received telephone support for their quit effort . The study was conducted entirely through phone and mail , allowing delivery of the intervention to both rural and urban users .  Self-reported rates of sustained abstinence ( no tobacco use at two months and six months ) were 24.5 % for the manual/video condition , and 18.4 % , for the LifeSign condition Background Epidemiological studies suggest that smokeless tobacco in the form of Swedish snus has been used by many smokers in Sc and inavia to quit smoking , but the efficacy of snus has so far not been evaluated in controlled clinical trials . Methods We conducted a r and omized , double-blind , placebo-controlled , clinical trial aim ed at assessing the efficacy of snus to help adult cigarette smokers in Serbia to substantially reduce , and , eventually , completely stop smoking . The study enrolled 319 healthy smokers aged 20 - 65 years at two occupational health centers in Bel grade , Serbia . Most of them ( 81 % ) expressed an interest to quit rather than just reduce their smoking . Study products were used ad libitum throughout the 48-week study period . The main study objective during the first 24 weeks was smoking reduction . The primary end-point was defined as a biologically verified reduction of ≥ 50 % in the average number of smoked cigarettes per day during week 21 - 24 compared to baseline . During week 25 - 48 participants were actively instructed to stop smoking completely . Outcome measures of biologically verified , complete smoking cessation included 1-week point prevalence rates at clinical visits after 12 , 24 , 36 , and 48 weeks , as well as 4- , 12- and 24-week continued cessation rates at the week 36 and 48 visits . Results At the week 24 visit , the proportion of participants who achieved the protocol definition of a ≥ 50 % smoking reduction was similar in the two treatment groups . However , the proportion that reported more extreme reductions ( ≥ 75 % ) was statistically significantly higher in the snus group than in the placebo group ( p < 0.01 ) . The results for biologically verified complete cessation suggested that participants in the snus group were more likely to quit smoking completely than the controls ; the odds ratio ( snus versus placebo ) for the protocol estimates of cessation varied between 1.9 to 3.4 , but these ratios were of borderline significance with p-values ranging from 0.04 - 0.10 . Snus was well tolerated and only 2/158 ( 1.3 % ) participants in the snus group discontinued treatment due to an adverse event ( in both cases unrelated to snus ) . Conclusions Swedish snus could promote smoking cessation among smokers in Serbia , that is , in a cultural setting without traditional use of oral , smokeless tobacco . Trial registration www . clinical trials.gov , identifier : Background The prevalence and correlates of hardcore smokers , who have high daily cigarette consumption , no quitting history and no intention to quit , have been studied in several western developed countries , but no previous trials of smoking cessation have tested intervention effectiveness for these smokers . The current study examined if hardcore smokers can benefit from smoking reduction intervention to achieve cessation , and explored the underlying reasons . Methods A posteriori analysis was conducted on data from a r and omized controlled trial of smoking reduction intervention on 1,154 smokers who did not want to quit . Odds ratios of 7-day point prevalence of abstinence , smoking reduction by at least 50 % and quit attempt at the 6-month follow-up comparing subgroups of smokers were analyzed . Results In hardcore smokers , the odds ratio comparing the quit rate between the intervention and control group was 4.18 ( 95 % CI : 0.51 - 34.65 ) , which was greater than non-hardcore smokers ( OR = 1.58 , 95 % CI : 0.98 - 2.54 ) . The number needed to treat for hardcore and non-hardcore smokers was 8.33 ( 95 % CI : 5.56 - 16.67 ) and 16.67 ( 95 % CI : 8.33 - 233.64 ) , respectively . In smokers who did not have quit attempt experience and those who smoked more than 15 cigarettes daily , the odds ratio comparing intervention and control group was 3.29 ( 95 % CI : 0.72 - 14.98 ) and 1.36 ( 95 % CI : 0.78 - 2.36 ) , respectively . Conclusions The a posteriori analysis provided pilot results that smoking reduction intervention may be effective to help hardcore smokers to quit and reduce smoking . Having no previous quit attempt was identified as more important than having large cigarette consumption in explaining the greater effectiveness of the intervention BACKGROUND Smoking reduction has been introduced as an alternative to smokers unable or unwilling to quit but has never been implemented in a population -based intervention . METHODS Two thous and four hundred eight daily smokers in all motivational stages were included in a r and omised population -based intervention study , in Copenhagen , Denmark . Smokers , unwilling or unable to quit , were encouraged to reduce their tobacco consumption . Furthermore , smokers in the high-intensity intervention were offered participation in smoking reduction groups . RESULTS Twenty-three percent of those who attended both baseline and 1 year visit reported reduction by at least 5 g and 8 % reported a halving or more . Halving of tobacco consumption was achieved significantly more often than in the background population , OR = 2.6 ( 1.6 - 4.4 ) , even when assuming that non- participants had not reduced , OR = 1.7 ( 1.0 - 2.8 ) . Reduction of at least 5 g doubled the probability of increased motivation to quit and a halving increased it more than four times . The reductions were not vali date d. Less than 2 % attended the smoking reduction groups . CONCLUSION The smoking reduction intervention was significant in self-reported reduction of tobacco consumption and subsequently increased motivation to quit . This may open new perspectives , with reduction as a first step towards cessation , a possible supplement to smoking cessation strategies OBJECTIVES Smoking is more common among patients with schizophrenia than it is in the general population . Varenicline , a partial and full agonist at the α4β2 and α7 nicotine acetylcholine receptors , respectively , has been shown to be an effective anti-smoking treatment . This study examined the effects of varenicline treatment on smoking reduction in patients with schizophrenia . METHODS Sixty smokers with schizophrenia were recruited and r and omized to receive either varenicline or placebo . Smoking behavior was assessed with the Minnesota Nicotine Withdrawal Scale ( mNWS ) , Brief Question naire of Smoking Urge ( QSU-brief ) , and Modified Cigarette Evaluation Question naire ( mCEQ ) . Exhaled carbon monoxide was also measured to assess smoking dependency and status . Data were analyzed with the two-tailed Student 's t-test , χ(2 ) test , and repeated measures ANOVA . RESULTS During the 8-week study , there was a significant time × group interaction , which showed that smoking decreased over time in the varenicline group . Expired CO levels also decreased in the varenicline group , showing a significant time effect , group effect , and time × group interaction . Total mCEQ scores decreased in the varenicline group , demonstrating a significant time × group interaction . Among the five domains of the mCEQ , the smoking satisfaction , psychological reward , and enjoyment of respiratory tract sensation domains showed significant time × group interactions in the varenicline group . The QSU-brief and mNWS demonstrated a significant time effect , but not significant time × group interactions . Adjunctive varenicline treatment with antipsychotics was generally well-tolerated and safe . CONCLUSIONS Varenicline showed significant efficacy in reducing smoking in people with schizophrenia Ninety-eight cigarette smokers attending the Newcastle upon Tyne Dental Hospital , wishing to reduce their tobacco consumption , received smoking reduction advice in combination with dental health instruction and periodontal care . Those advised against smoking showed a greater reduction ( P < 0.001 ) in reported cigarette consumption during treatment and follow-up , compared with 38 control subjects who received  dental health instruction but no advice against smoking . Fifty percent of intervention subjects reported reducing to half or less than half of their initial cigarette consumption , compared with 24 % for controls . Eighty percent of those advised against smoking reported some reduction , against 29 % for controls . The reported smoking cessation rate in the intervention group was 13.3 % , compared with 5.3 % in the control subjects . The results indicate that advice against smoking combined with dental health instruction and periodontal care can be an effective aid to reducing tobacco Treatment for substance use disorders ( SUD ) provides an opportunity to use voucher-based treatment for smoking .  Nicotine replacement ( NRT ) could improve outcomes previously observed with vouchers without NRT . METHODS A r and omized controlled trial compared contingent vouchers ( CV ) for smoking abstinence to noncontingent vouchers ( NV ) , when all received counseling and NRT .  Smokers who had not sought smoking treatment ( n=340 ) in residential SUD treatment were provided 14days of vouchers for complete smoking abstinence per exhaled carbon monoxide ( CO ) after a 5-day smoking reduction period , or vouchers only for breath sample s , plus brief advice ( four sessions ) and 8weeks of NRT . RESULTS Within treatment , 20 % had complete abstinence with CV , 5 % with NV ( p<.001 ) , and participants showed 50 % of days abstinent in CV compared to 22 % in NV ( p<.001 ) . Across 1 , 3 , 6 and 12months after r and omization , CV result ed in significantly fewer cigarettes per day ( p<.01 ) and fewer days smoking ( p<.01 ) , but with small effects . Point-prevalence abstinence differences across follow-up ( e.g. , 4 % CV , 2 % in NV at 6 and 12months ) were not significant . No differences in substance use were seen . CONCLUSIONS Within-treatment effects on abstinence are stronger than in a prior study of the same CV with BA but without NRT , but NRT does not improve abstinence after vouchers end . Implication s for voucher-based treatment include investigating effects when combined with stronger smoking medications and using motivational interviewing . Smoking treatment does not harm SUD recovery AIMS To test whether , in comparison to usual care , brief motivational or reduction interventions increase quit attempts ( QA ) or abstinence among smokers who are not ready to quit . DESIGN A parallel-group r and omized controlled trial of brief motivational ( n = 185 ) , reduction ( n = 186 ) or usual care ( n = 189 ) telephone interventions delivered over the course of 4 weeks . Outcomes were assessed at 6- and 12-month follow-ups . No medication was provided . SETTING United States . PARTICIPANTS A total of 560 adult smokers of ≥ 10 cigarettes per day who were not ready to quit in the next 30 days . MEASUREMENTS The primary outcomes were whether participants made a QA that lasted ≥ 24 hours and whether they made a QA of any length between baseline and 6 months . Secondary outcomes included 7-day point-prevalence abstinence at 6 and 12 months . The 12-month follow-up was added after the study began . FINDINGS A priori-defined comparisons were between motivational versus usual care and reduction versus usual care conditions . The probability of making a QA that lasted ≥ 24 hours was not significantly different between the motivational ( 38 % ) or the reduction ( 31 % ) conditions and the usual care ( 34 % ) condition [ motivational versus usual care odds ratio ( OR ) = 1.19 , 95 % confidence interval ( CI ) = 0.78 - 1.82 ; reduction versus usual care OR = 0.89 , 95 % CI = 0.57 - 1.36 ] . Bayes factors ranged from 0.13 to 0.18 . Findings regarding a QA of any length were similar . At 6 months , the motivational condition had marginally more abstinence than usual care ( 11 versus 5 % , OR = 2.17 , 95 % CI = 0.99 - 4.77 ) , but the reduction condition was not significantly different from usual care ( 8 versus 5 % , OR = 1.57 , 95 % CI = 0.69 - 3.59 ) . At 12 months , the motivational condition had significantly more abstinence than usual care ( 10 versus 4 % , OR = 2.80 , 95 % CI = 1.14 - 6.88 ) and the reduction condition had marginally more abstinence than usual care ( 9 versus 4 % , OR = 2.45 , 95 % CI = 0.98 - 6.09 ) . CONCLUSIONS Among adult smokers who are not ready to quit , both logistic regression 
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Although there was some evidence from within- study comparisons that behavioural support for reduction to quit result ed in higher quit rates than self-help re sources alone , the relative efficacy of various other characteristics of reduction-to-quit interventions investigated through within- and between- study comparisons did not provide any evidence that they enhanced the success of reduction-to-quit interventions .
Pre-quit AEs , SAEs and nicotine withdrawal symptoms were measured variably and infrequently across studies .
There was some evidence that AEs occurred more frequently in studies that compared reduction using pharmacotherapy versus no pharmacotherapy ; however , the AEs reported were mild and usual symptoms associated with NRT use .
There was no clear evidence that the number of people reporting SAEs , or changes in withdrawal symptoms , differed between trial arms .
There is moderate-certainty evidence that neither reduction-to-quit nor abrupt quitting interventions result in superior long-term quit rates when compared with one another .
There is also low-certainty evidence to suggest that reduction-to-quit interventions may be more effective when pharmacotherapy is used as an aid , particularly fast-acting NRT or varenicline ( moderate-certainty evidence ) .
Evidence for any adverse effects of reduction-to-quit interventions was sparse , but available data suggested no excess of pre-quit SAEs or withdrawal symptoms .