***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: Subjects ( N = 139 ) were assigned to intensive behavioral or to low-contact smoking treatment and to 2-mg nicotine gum or to placebo gum in a 2 X 2 factorial design . The 2-mg gum produced higher abstinence rates than did the placebo . Subjects receiving the low-contact condition plus the 2-mg nicotine gum had excellent abstinence rates at both 26 weeks ( 56 % abstainers ) and 52 weeks ( 50 % abstainers ) . Smokers who scored at the median on a measure of physical dependence to nicotine were more likely to benefit by nicotine gum treatment than subjects who scored either higher or lower , but this relation was nonsignificant . The results of this study are compared with an earlier nonblind trial While sex differences in the nicotine withdrawal ( NW ) symptoms and craving ( NC ) have been extensively described in adult cigarette smokers , few studies have investigated these phenomena in adolescents . We investigated the effect of gender and hormonal contraception ( HC ) on NW and NC during the first 14 days of cessation in adolescent smokers using data from a r and omized , placebo-controlled  , double-blind trial of the transdermal nicotine replacement therapy for smoking cessation . Analyses showed similar levels of NW severity in males and females , regardless of HC use . However , significantly higher NC was observed in females compared to males , ( 2.22+/-0.12 vs. 1.65+/-1.14 ; p=0.003 ) . Further , females not using HC reported the highest level of NC ( 2.38+/-0.16 ) followed by females using HC ( 2.08+/-0.25 ) and males ( 1.71+/-0.16 ; p=0.007 ) . The current findings suggest that adolescent females experience similar NW severity to males , but have stronger NC . Further , the use of hormonal contraceptives may impact the severity of craving . Addressing these different symptoms in adolescents may be useful in increasing smoking cessation rates in this special population of smokers BACKGROUND This study was conducted to determine the efficacy of the nicotine patch in smoking cessation when combined with self-help material s , three brief visits , and telephone counseling . METHODS One hundred fifty-nine healthy volunteers who smoked at least one pack of cigarettes per day and desired to quit smoking were enrolled in a double-blind trial with 6-week treatment and 6-month follow-up periods . After review of self-help material s , subjects were r and omly assigned to regimens of nicotine or placebo patches . Subjects wore two patches per day for 4 weeks ( 25 mg of nicotine per 24 hours ) , then one patch per day for 2 weeks . Return visits were at the ends of weeks 4 and 6 . Telephone counseling was given during weeks 1 , 2 , 3 , and 5 . Abstinence at 6 weeks was defined as zero cigarettes smoked for the previous 28 days , verified by exhaled carbon monoxide less than 8 ppm at 4 weeks and 6 weeks . Abstinence at 3 and 6 months was defined as self-report of zero cigarettes since the previous contact , verified by carbon monoxide value at 6 months . RESULTS Abstinence rates at 6 weeks , 3 months , and 6 months were 29.5 % , 21.8 % , and 20.5 % in the active group , and 8.8 % , 3.8 % , and 2.5 % in the placebo group ( P < or = .001 for each comparison ) , respectively . Skin irritation was the main side effect , causing 1.3 % to drop out . CONCLUSION The nicotine patch is efficacious in smoking cessation over a 6-month period , when combined with only self-help material s , three brief visits , and telephone counseling The use of nicotine chewing gum combined with psychological support improves the success rate in stopping smoking . We studied the safety and efficacy of a transdermal nicotine patch in stopping smoking . We conducted a double-blind r and omized study comparing the effect of a 16-hour nicotine patch ( 15 + /- 3.5 mg of nicotine in 16 hours ) with those of a placebo patch . Of the 289 smokers ( 207 women and 82 men ) enrolled in the study , 145 were treated with nicotine patches and 144 with placebo patches for 16 weeks . The rates of sustained abstinence were significantly better with active treatment than with the placebo : 53 , 41 , 24 and 17 % of those in the nicotine-patch group were abstinent after 6 , 12 , 26 , and 52 weeks , respectively , as compared with 17 , 10 , 5 and 4 % of those in the placebo-patch group ( p less than 0.0001 ) . Only two subjects with the nicotine patch and one with the placebo patch withdrew from the study because of side effects . The nicotine skin patch proved to be safe and effective , as demonstrated by a higher rate of abstinence than with the placebo AIMS Of six established nicotine replacement therapy ( NRT ) formulations , only the gum and patch have been tested without specialist clinic support in placebo-controlled trials . We aim ed to broaden the evidence base by examining if the nicotine nasal spray ( NNS ) could be effective with only brief support in general practice . DESIGN R and omized placebo-controlled trial . SETTING Twenty-seven English general practice s. PARTICIPANTS A total of 761 heavy smokers received brief support and 12 weeks of treatment with NNS ( 506 ) or placebo ( 255 ) . MEASUREMENTS The primary outcome was biochemically verified complete abstinence from smoking throughout weeks 3 - 12 . FINDINGS NNS compared with placebo more than doubled the number who successfully stopped smoking [ 15.4 % versus 6.7 % , odds ratio ( OR ) = 2.6 , 95 % confidence interval ( CI ) = 1.5 - 4.4 ] . Many participants reported minor irritant adverse symptoms . NNS was particularly effective among those who were more highly dependent on nicotine ( OR = 6.17 , 95 % CI = 2.13 - 17.9 ) . Of those who failed to stop during the first week ( 417 , 54.8 % ) , only one ( 0.2 % ) achieved later success . CONCLUSIONS NNS is effective when given in primary care . The benefit was lower than in a specialist clinic but similar to that with the nicotine patch in primary care . Unlike most other NRT formulations , bupropion or varenicline , NNS was especially helpful for more dependent smokers . Continuing treatment of those initially failing was not beneficial . An initial 1-week prescription to those more dependent on nicotine is likely to be the most cost-effective NNS treatment protocol . These results should offer support to the effectiveness of the other NRT formulations untested in this setting In a r and omized smoking cessation study 211 , 203 and 82 persons were supported with nicotine , silver acetate and ordinary chewing gum , respectively . After 26 weeks there was no overall difference in number of abstainers between treatments . Participants were divided into subsets with low and high weighted packyears consumption ( WPY ) which modifies tobacco consumption by nicotine content . Abstainer rates in the total population controlled for treatment decreased with increasing WPY ( P<0.005 ) . In participants with low WPY abstainer rate was higher in the silver acetate group compared to the nicotine ( P<0.0005 ) and ordinary ( P<0.05 ) chewing gum groups . Nicotine chewing gum was more effective than silver acetate ( P<0.05 ) and ordinary ( P<0.05 ) chewing gum in smokers with high WPY . Ratings on some inconveniences experienced during earlier attempts to quit smoking influenced the ability to break the habit but had no influence on chewing gum effects . This study indicated that through consideration of smoking history it should be possible to individualize pharmacological support to smokers wanting to quit , with silver acetate chewing gum most effective for smokers with a low WPY and nicotine chewing gum most effective for smokers with a high WPY BACKGROUND Substantial concerns have been raised about the neuropsychiatric safety of the smoking cessation medications varenicline and bupropion . Their efficacy relative to nicotine patch largely relies on indirect comparisons , and there is limited information on safety and efficacy in smokers with psychiatric disorders . We compared the relative neuropsychiatric safety risk and efficacy of varenicline and bupropion with nicotine patch and placebo in smokers with and without psychiatric disorders . METHODS We did a r and omised , double-blind , triple-dummy , placebo-controlled and active-controlled ( nicotine patch ; 21 mg per day with taper ) trial of varenicline ( 1 mg twice a day ) and bupropion ( 150 mg twice a day ) for 12 weeks with 12-week non-treatment follow-up done at 140 centres ( clinical trial centres , academic centres , and outpatient clinics ) in 16 countries between Nov 30 , 2011 , and Jan 13 , 2015 . Participants were motivated-to-quit smokers with and without psychiatric disorders who received brief cessation counselling at each visit . R and omisation was computer generated ( 1:1:1:1 ratio ) . Participants , investigators , and research personnel were masked to treatment assignments . The primary endpoint was the incidence of a composite measure of moderate and severe neuropsychiatric adverse events . The main efficacy endpoint was biochemically confirmed continuous abstinence for weeks 9 - 12 . All participants r and omly assigned were included in the efficacy analysis and those who received treatment were included in the safety analysis . The trial is registered at Clinical Trials.gov ( number NCT01456936 ) and is now closed . FINDINGS 8144 participants were r and omly assigned , 4116 to the psychiatric cohort ( 4074 included in the safety analysis ) and 4028 to the non-psychiatric cohort ( 3984 included in the safety analysis ) . In the non-psychiatric cohort , 13 ( 1·3 % ) of 990 participants reported moderate and severe neuropsychiatric adverse events in the varenicline group , 22 ( 2·2 % ) of 989 in the bupropion group , 25 ( 2·5 % ) of 1006 in the nicotine patch group , and 24 ( 2·4 % ) of 999 in the placebo group . The varenicline-placebo and  bupropion-placebo risk differences ( RDs ) for moderate and severe neuropsychiatric adverse events were -1·28 ( 95 % CI -2·40 to -0·15 ) and -0·08 ( -1·37 to 1·21 ) , respectively ; the RDs for comparisons with nicotine patch were -1·07 ( -2·21 to 0·08 ) and 0·13 ( -1·19 to 1·45 ) , respectively . In the psychiatric cohort , moderate and severe neuropsychiatric adverse events were reported in 67 ( 6·5 % ) of 1026 participants in the varenicline group , 68 ( 6·7 % ) of 1017 in the bupropion group , 53 ( 5·2 % ) of 1016 in the nicotine patch group , and 50 ( 4·9 % ) of 1015 in the placebo group . The varenicline-placebo  and bupropion-placebo RDs were 1·59 ( 95 % CI -0·42 to 3·59 ) and 1·78 ( -0·24 to 3·81 ) , respectively ; the RDs versus nicotine patch were 1·22 ( -0·81 to 3·25 ) and 1·42 ( -0·63 to 3·46 ) , respectively  . Varenicline-treated participants achieved higher abstinence rates than those on placebo ( odds ratio [ OR ] 3·61 , 95 % CI 3·07 to 4·24 ) , nicotine patch ( 1·68 , 1·46 to 1·93 ) , and bupropion ( 1·75 , 1·52 to 2·01 ) . Those on bupropion and nicotine patch achieved higher abstinence rates than those on placebo ( OR 2·07 [ 1·75 to 2·45 ] and 2·15 [ 1·82 to 2·54 ] , respectively ) . Across cohorts , the most frequent adverse events by treatment group were nausea  ( varenicline , 25 % [ 511 of 2016 participants ] ) , insomnia  ( bupropion , 12 % [ 245 of 2006 participants ] ) , abnormal dreams  ( nicotine patch , 12 % [ 251 of 2022 participants ] ) , and headache ( placebo , 10 % [ 199 of 2014 participants ] ) . Efficacy treatment comparison did not differ by cohort . INTERPRETATION The study did not show a significant increase in neuropsychiatric adverse events  attributable to varenicline or bupropion relative to nicotine patch or placebo . Varenicline was 
    Output:
    
There is high- quality evidence that all of the licensed forms of NRT ( gum , transdermal patch , nasal spray , inhalator and sublingual tablets/lozenges ) can help people who make a quit attempt to increase their chances of successfully stopping smoking .
NRTs increase the rate of quitting by 50 % to 60 % , regardless of setting , and further research is very unlikely to change our confidence in the estimate of the effect .
The relative effectiveness of NRT  appears to be largely independent of the intensity of additional support provided to the individual .
Provision of more intense levels of support , although beneficial in facilitating the likelihood of quitting , is not essential to the success of NRT .
NRT often causes minor irritation of the site through which it is administered , and in rare cases can cause non-ischaemic chest pain and palpitations