This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn.

The study compared three different benefit designs for treating tobacco dependence for a group of insured adult smokers. The three benefit designs were pharmacotherapy alone, pharmacotherapy plus counselling services, and pharmacotherapy conditional on participation in a counselling programme. The pharmacotherapy treatments were bupropion SR (Zyban) and nicotine replacement therapy (NRT). NRT included gum, patch, nasal spray, inhaler and lozenges. Proactive telephone counselling was chosen as the method of counselling. In addition, all patients received a smoking self-help kit. Participants received $5 for each telephone interviewed that they completed. If the participant relapsed, he/she was sent a "recycle kit" and the specialist re-initiated the quitting process.

Treatment.

Cost-effectiveness analysis.

The study population comprised adult smokers enrolled in a large preferred provider organisation. To be eligible for the study, individuals had to be aged 18 years or older, not in receipt of any smoking cessation benefits at the time of enrolment, and had to be a current smoker who had smoked at least one cigarette in the last 7 days. Individuals were under no obligation to use any of the tobacco dependence treatments covered in the study. Enrolees were not eligible if they were pregnant, or had poor health, coronary artery disease, heart disease, arrhythmia, heart attack or myocardial infarction, cardiovascular disease, angina pectoris or congestive heart failure.

The setting was primary care. The economic study was carried out in California, USA.

The clinical and resource use data were collected during the 8 months of the study from 1 May 2001 to 31 December 2001. The price year was unclear.

The same patients formed the prospective source of both clinical and resource use data. All costs were based on the actual use of treatment by study participants in each group.

Of 113,000 health plan enrolees, 803 responded to the invitation to participate in the study. Two hundred and thirty-five were excluded, and of those who completed the baseline interview and met the inclusion criteria, 175 did not return the consent form. Therefore, 393 were randomly assigned to the three groups. There were 126 participants in the pharmacotherapy along group, 140 in the pharmacotherapy plus counselling group, and 127 in the pharmacotherapy if counselling group. The numbers of completers in each group were 104, 115 and 104, respectively. Power calculations were not reported.

The study was a single-centred, randomised controlled trial with an 8-month follow-up. The methods of randomisation and allocation concealment were not reported. The loss to follow-up was 22 (17%) participants in the pharmacotherapy alone group, 25 (18%) in the pharmacotherapy plus counselling group, and 23 (18%) in the pharmacotherapy if counselling group. The overall sample proportion of participant lost to follow-up at 8 months was 18%.

The primary outcomes of interest were:

making a quit attempt (i.e. stopped smoking for 1 or more days during the study);

quitting during the study (i.e. stopped smoking for 7 or more days in a row during the study); and

prevalent abstinence (i.e. had not smoked a cigarette for 7 or more days in a row at the 8-month follow-up interview).

Additional outcomes of interest included use of the pharmacotherapy benefit and participation in the proactive telephone counselling programme. Baseline and 8-month follow-up data on smoking and quitting behaviours were collected by telephone using a computer-administered telephone interview system. An intention to treat analysis was reported. The groups were broadly comparable at baseline in demographic, smoking and control variables, except for a lower income reported in the drugs plus counselling group.

The bivariate analysis of quitting outcomes by treatment group found no statistically significant differences across groups.

The average rate of making a quit attempt was 48% (range: 43 to 55).

Quit rates during the study averaged 31% (range: 26 to 37).

Prevalent abstinence rates at 8 months averaged 16% (range: 13 to 19).

Use of the pharmacotherapy benefit did not vary across treatment groups. On average, 20% of participants filled a prescription for one of the covered medications.

These findings were generally confirmed by the logistic regression. The exception was that the pharmacotherapy plus counselling group showed a statistically significantly lower adjusted odd ratio (0.5, 95% confidence interval: 0.3 to 0.9) of making a quit attempt compared with the pharmacotherapy alone group.

Other statistically significant differences were observed in enrolment in the proactive telephone counselling programme. In comparison, almost three times as many participants in the pharmacotherapy if counselling group (24%) enrolled in the programme compared with the pharmacotherapy plus counselling group (8%).

In addition, if multiple treatment use was considered, only 4 out of 34 participants who used any treatment chose only counselling in the pharmacotherapy plus counselling group.

In the context of a health insurance benefit design, the addition of proactive telephone counselling to pharmacotherapy had no positive impact on smoking cessation practices and quit rates in comparison with pharmacotherapy alone. In addition, the findings showed that, even when there was an increase in the use of proactive telephone counselling, pharmacotherapy conditional on participation in counselling did not show any higher quit rates than the group with unlinked counselling and pharmacotherapy benefits.

The authors did not derive a summary measure of benefit. They used different benefit measures (quit attempt, quit during study, and prevalent abstinence). These health benefits were derived from the effectiveness analysis.

The costs of treatment for each group were estimated. These were based on treatment usage and the costs of each covered drug for a 12-week course of treatment to the health insurer, the cost of enrolment in the proactive telephone counselling programme, and the cost of the self-help kit sent to all study participants. Resource use was directly analysed from the study patients. The pharmacy manager of the health insurer provided data on filled prescriptions, while the programme itself provided data on enrolment in the proactive telephone programme. The unit costs were extracted directly from these sources. Discounting was not necessary as the follow-up period was only 8 months. The average costs were reported. The unit costs and quantities were reported for the resources included. Although the price year was not reported, the cost data were obtained from 1 May 2001 to 31 December 2001.

Although the authors seem to have individual patient data on costs, no statistical analysis of the costs was performed.

No productivity costs were included.

US dollars ($).

Adjusted odds ratios of quitting behaviours by treatment group, along with 95% confidence intervals, were estimated from the coefficients in the logistics models.

See the 'Effectiveness Results' section above.

The total costs of covered treatments were $10,767 for the pharmacotherapy alone group, $15,155 for the pharmacotherapy plus counselling group, and $15,597 for the pharmacotherapy if counselling group.

The total costs per patient were $85 for the pharmacotherapy alone group, $108 for the pharmacotherapy plus counselling group, and $128 for the pharmacotherapy if counselling group.

The costs per quit attempt during the study were $156 for the pharmacotherapy alone group, $253 for the pharmacotherapy plus counselling group, and $274 for the pharmacotherapy if counselling group.

The costs per quit during the study were $234 for the pharmacotherapy alone group, $410 for the pharmacotherapy plus counselling group, and $410 for the pharmacotherapy if counselling group.

The costs per prevalent abstinence were $449 for the pharmacotherapy alone group, $842 for the pharmacotherapy plus counselling group, and $709 for the pharmacotherapy if counselling group.

These results demonstrated that the pharmacotherapy alone group consistently showed the lowest costs per participant and the lowest costs for achieving each of the major study outcomes.

No incremental analyses were reported.

Coverage for pharmacotherapy only was clearly the most efficient benefit design for treating tobacco dependence, achieving similar outcomes at a lower cost. In addition, there were three other major findings. First, adding coverage for proactive telephone counselling to coverage for pharmacotherapy for treating tobacco dependence did not increase quit attempts or quit rates among adult smokers. Second, linking access to drugs to counselling by restricting drug coverage to those enrolled in proactive telephone counselling did not act as a barrier to use of these medications, or as complement that enhanced the effect of the drugs. Third, the cost of adding coverage for telephone counselling to a pharmacotherapy benefit was substantial, increasing the costs approximately two-fold to achieve each major quitting outcome.

The comparator was explicitly justified and was intended to reflect routine practice in the authors' setting. However, readers should consider if this is an adequate comparator in their own settings.

Although the authors stated that this was a randomised trial, the methods of randomisation and allocation concealment were not reported. Nevertheless, the groups appear to have been comparable in terms of their baseline characteristics. No power calculations were reported. Although the time horizon of the study was 8 months, the authors stated that they would have liked to have conducted the study for one full year and to have collected outcome data one year post-intervention. The fact that the participants were volunteers and that the data were self-reported should be taken into consideration when interpreting the results. The statistical analysis was explained and handled credibly.

Validity of estimate of measure of benefits:

Please refer to the comments in the 'Validity of estimate of measure of effectiveness' field (above).

The perspective of the study was that of a private health insurer (a preferred provider organisation). All the relevant cost categories, as well as their individual costs, were taken into consideration. Resource use was collected alongside the trial and the unit costs came from the health insurer's actual costs. Although no price year was reported, the dates when the resource use data were collected were given; these may help future extrapolation exercises. The unit costs and resource use were adequately reported. As the time horizon was 8 months, the authors, appropriately, did not discount the costs or benefits. Uncertainty and variability in the costs was not reported.

The authors addressed the generalisability of the results. The findings were compared with those from other relevant studies, although this was the first randomised trial to assess the effects and costs of different covered benefit designs for treating tobacco dependence. Whilst the authors did not report any limitations to their study, the reader is referred to the 'Validity of estimate of measure of effectiveness' field (above) for comments relating to internal validity.

The findings indicate that employers and health plans might achieve a significant impact on quitting behaviours and smoking rates at a relative low cost by covering pharmacotherapy only. In addition, they might cover proactive telephone counselling for those smokers for whom pharmacotherapy is not medically indicated or desired, as recent research data have found that these interventions significantly increase the odds of quitting smoking over less intensive treatments or no treatment. The findings of this study also show that requiring enrolment in order to obtain drug coverage does not deter smokers from getting prescriptions for covered tobacco dependence medications. According to the authors, further research should address the question of whether adding coverage for face-to-face counselling to a pharmacotherapy benefit increases quit and abstinence rates. The authors also suggest that national guidelines for tobacco dependence treatments need to be updated and revised to address the effectiveness of combined therapies.

Funded by a grant from the Tobacco-Related Disease Research Program.