The study examined two population-based programmes promoting free smoking cessation products, which were used to encourage smokers to call the New York State Smokers' Quitline.

The first intervention was a press announcement urging adult smokers to call the Quitline to obtain a voucher for a free 2-week supply of nicotine patches or gum (nicotine replacement therapy, NRT).

The second intervention consisted of two newspaper advertisements for the quitline, one of which offered a free stop smoking guide and another one that offered the same guide plus a free quit smoking aide called Better Quit (BQ). The BQ is a plastic stick designed to look like a cigarette, intended to be used by smokers as a cigarette substitute to help them cope with urges to smoke.

Both offers were time-limited and smokers were required to call the toll-free New York State Smokers' Quitline to participate.

Primary prevention.

The objective of the study was to assess the cost-effectiveness of the two programmes for smoking cessation in the USA. The authors stated that the use of telephone counselling services had been advocated to support smoking cessation attempts. The main advantage of quitlines is their potential to reach large numbers of smokers. However, the difficulty lies in getting smokers to call. Therefore, the clinical and economic impact of the two programmes encouraging smokers to call a quitline was investigated in the current analysis. Specifically, the free 2-week nicotine voucher was compared with a strategy of no intervention, while the two newspaper advertisements were compared with each other (i.e. guide versus guide plus BQ). The authors did not report the economic perspective of the study.

Cost-effectiveness analysis.

The study population comprised adult (18 years and older) smokers of 10 cigarettes per day, who reported no medical contraindications for using either nicotine patch or gum.

The setting was the community. The economic study was carried out in the USA.

The effectiveness data, resource use data and costs were gathered between 2003 and 2004. The price year was not reported.

The effectiveness evidence was derived from a single study.

The costing was carried out prospectively on the same sample of patients as that included in the effectiveness analysis.

Power calculations were not reported. In the first comparison, a sample of 2,461 eligible individuals identified between July and August 2003 was compared with a historical control group of 515 smokers who were identified through a telephone survey in 2001. Of the 2,461 smokers offered the 2-week supply of NRT, 1,100 individuals were randomly selected and considered for the follow-up analysis. Embedded with the follow-up study was another analysis in which half the smokers were sent the guide plus BQ while the other half did not receive BQ. There were 408 individuals in the BQ arm and 324 in the non-BQ arm. Demographics and other characteristics of the participants enrolled in the study were provided.

This was a prospective cohort study with a historical control, which was carried out in two counties in New York State. A random sample of patients was selected for follow-up analysis and for the embedded experiment, in which patients were randomised to receive a guide (non-BQ arm) or the same guide plus BQ (BQ-arm). The length of follow-up was 4 to 6 months. The number of patients available in the follow-up analysis was 732. The numbers of patients included at the final assessment in the embedded study were 408 in the BQ group and 324 in the non-BQ group.

The analysis of the clinical study was restricted to those individuals with available follow-up data. The outcome measures used in the analysis were response to promotions, quit attempts and quit rate. Response was evaluated by monitoring the volume of calls to the quitline in different periods (before, during and after the promotions). Quit rates were based on self-reported smoking behaviour and were defined as individuals not smoking and not having smoked a cigarette in the previous 7 days. A multiple regression analysis was carried out to estimate the relative risk for quitting amongst smokers who received the free NRT voucher compared with those who did not, adjusting for age, gender, race, type of insurance, and use of other quit methods since calling the quitline. The authors noted that the study participants were comparable to those who were not available at follow-up, but made no explicit comparisons of the baseline characteristics.

In the comparison between free NRT voucher and no intervention, the median number of calls per day to the quitline was 6.0 in the 2 weeks before the promotion, 148.0 during the implementation of the programme (25-fold increase), and 26.5 in the period after the promotion. It took 1 month after the promotion was discontinued to return to the pre-promotion level of calls.

In the second comparison (guide versus guide plus BQ), the median number of calls per day was 7.0 in the period before the control advertisement was run, 14.0 during the running of this advertisement, and 27.5 in the period immediately after the newspaper advertisement offering BQ appeared. Thus, the guide advertisement increased the number of calls 2-fold, while the guide plus BQ advertisement increased the number of calls by about 4-fold.

In the first comparison, the proportion of quit attempts was 79% and the quit rate was 22% in individuals receiving free NRT.

Among individuals who redeemed their vouchers, 83% said they used the medications at least once, while 60% said they use the medications for a minimum of 14 days.

The quit rate was comparable for those who reported using either the nicotine patch or nicotine gum. It was much higher than the quit rate for those participants who said that they either did not redeem the voucher or did not use the medication (6%). The quit rate for the historical control group was 12%.

Multiple regression analysis showed that the relative risk for quitting with free NRT voucher over no intervention was 1.77 (95% confidence interval: 1.17 to 2.68).

In the embedded study, 20% of individuals in the BQ group were not smoking at follow-up in comparison with 24% of those who did not receive BQ, a difference that was not statistically significant. Self-reported use of BQ was not associated with a higher quit rate.

The effectiveness analysis showed that the press announcement of a programme giving away a voucher for a free 2-week supply of NRT was effective in improving the volume of calls to the quitline and the effective quit rate in comparison with other smoking cessation strategies. The use of newspaper advertisements for the quitline also increased the number of calls, although the increase was lower than for the free 2-week supply of NRT. Similar results were obtained for the guide and guide plus BQ strategies.

The benefit measure was the improvement in response (i.e. change in volumes of calls to the quitline). This was derived directly from the effectiveness analysis.

The perspective of the economic analysis was not explicitly reported. The analysis included the costs associated with medication and paid newspaper advertisements for the free 2-week supply of NRT, and BQ cigarette substitute and newspaper advertisements for the BQ strategy. The unit costs were reported for some categories of costs. Resource consumption was based on the actual number of patients enrolled in the study, as reported in the effectiveness study. The source of the costs was not explicitly stated. Discounting was not relevant as the costs were incurred during less than 2 years. The costs were gathered in 2003 and 2004 but the price year was not explicitly stated.

The indirect costs were not considered.

US dollars ($).

The costs were treated deterministically.

A sensitivity analysis was not performed.

See the 'Effectiveness Results' section.

The total cost of the free NRT voucher was $51,304.

The total cost for the guide and the guide plus BQ were not reported, although it was noted that the cost of the newspaper advertisement was $3,342.

Incremental cost-effectiveness ratios were calculated in order to combine the costs and benefits of the alternative strategies over no intervention.

The incremental cost per extra call to the quitline was $11 with the free NRT voucher, $239 with the guide, and $80 with the guide plus BQ.

Offering a free 2-week voucher for nicotine replacement therapy (NRT) was a cost-effective strategy for enhancing calls to quitlines in order to improve smoking quit rates in the USA.

The rationale for the selection of the comparators was clear in that the new programmes based on advertisements were compared with strategies of no intervention. The programmes were described in detail and were implemented to induce smokers to call quitlines. You should decide whether they are valid comparators in your own setting.

The effectiveness evidence was derived from a particular design in which a prospective cohort of individuals was compared with a historical control group on the one hand, whilst on the other hand, a sample of patients for which follow-up data were available was randomised to receive or not receive BQ. The authors did not provide a justification for the choice of this embedded design. The non-randomised part of the study was open to selection bias. Further, the substantial loss to follow-up may have adversely affected the degree to which the study sample was representative of the study population. The authors pointed out that non-participants were comparable with individuals who were available at follow-up, but baseline characteristics were not reported. However, statistical analyses were carried out to deal with potential baseline differences between the groups.

It was unclear whether the length of follow-up was appropriate. The impact of time differences between groups (especially with respect to the historical control) could have introduced some time-related bias. Another limitation of the analysis was the use of self-reported data, which were not validated using objective measures. Finally, the analysis was restricted to treatment completers only. These issues should be considered when assessing the validity of the clinical analysis.

The summary benefit measure was specific to the intervention considered in the study. Thus, it will not be comparable with the benefits of other health care interventions; rather, it represents an intermediate measure. The use of a more widely used measure such as quit rate would have been interesting.

The analysis of the costs was restricted to the costs associated with the advertisement programmes. Other costs borne, for example, by individuals such as out-of-pocket expenses for NRT outside the free supply period were not considered. The results of the analysis were presented selectively and were not extensively reported. The unit costs were given for some items, but it would probably be difficult to replicate the analysis in other settings as limited details of the method and conduct of the economic evaluation were provided. For example, the sources of the costs were not reported. The period during which the cost and resource use data were gathered was reported, but a single price year was not stated. In addition, statistical analyses of the costs were not performed and the cost estimates were specific to the study setting.

The authors did not report the results from other studies, nor make extensive comparisons with them, although they did note that their clinical results were consistent with those in the published literature. The issue of the generalisability of the study results to other settings was not explicitly addressed and sensitivity analyses were not performed, which limits the external validity of the study. The use of a longer follow-up would have been useful in terms of estimating the true quit rate among smokers. The analysis referred to the general population of smokers and this was reflected in the authors' conclusions.

The current study supports the use of advertisements promoting free NRT to help smokers quit. The authors stated that further studies should be carried out to corroborate the current findings.

None stated.

Because readers are likely to encounter and assess individual publications, NHS EED abstracts reflect the original publication as it is written, as a stand-alone paper. Where NHS EED abstractors are able to identify positively that a publication is significantly linked to or informed by other publications, these will be referenced in the text of the abstract and their bibliographic details recorded here for information

Zhu SH, Andrson CM, Tedeschi GJ, et al. Evidence of real world effectiveness of a telephone quitline for smokers. N Engl J Med 2002;347:1087-93.

Cummings KM, Fix B, Celestino P, et al. Reach, efficacy and cost-effectiveness of free nicotine medication give-away programs. J Public Health Manage Pract 2006;12:37-43.

Miller N, Frieden TR, Liu SY, et al. Effectiveness of a large-scale free nicotine patch distribution program. Lancet 2005;365:1849-54.

This record was compiled by CRD commissioned reviewers according to a set of guidelines developed in collaboration with a group of leading health economists.