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A cluster-randomised controlled trial of a brief training session to facilitate general practitioner referral to smoking cessation treatment
  1. H McRobbie1,2,
  2. P Hajek1,
  3. G Feder1,
  4. S Eldridge1
  1. 1
    Barts and The London, Queen Mary’s School of Medicine and Dentistry, London, UK
  2. 2
    Department of General Practice and Primary Health Care, The University of Auckland, New Zealand
  1. Dr H McRobbie, Department of General Practice and Primary Health Care, PO Box 28854, Remuera, Auckland, New Zealand; hayden.mcrobbie{at}


Objectives: General practitioners (GPs) are the main source of referrals to specialist smoking cessation services (SSCS), but the referral rates are low. We evaluated effects of a brief GP training session on the number of referrals received by their local SSCS.

Methods: A cluster-randomised controlled trial was undertaken across three East London primary care trusts. A total of 91 GPs were randomly allocated to a training session or usual care. Participants in the intervention arm were offered a 40-min training session addressing the rationale and skills for referral of smokers for treatment. Participants in the usual care arm received referral guidance by post. The main outcome measure was the number of referrals recorded by the SSCS over 3 months after the intervention.

Results: Over the 3-month baseline period the average number of referrals per GP was 1.0 and 0.6 in the intervention and usual care arms, respectively. During the post-intervention period the mean number of referrals was 6.4 and 1.8 per GP. When adjusting for baseline variables the incidence rate ratio for the referrals from the intervention arm compared to usual care was 4.9 (p<0.001; 95 CI 1.7 to 14.7).

Conclusion: A brief training session can significantly increase GP referral to smoking cessation services.

Trial registration: National Research Register, Department of Health, UK N0261148824 (available online at:  N0261148824)

Statistics from

In countries with a high public awareness of the dangers of smoking and relatively low smoking prevalence, such as the US and the UK, a key challenge is informing the remaining smokers who are predominantly dependent13 about the availability and usefulness of existing treatments, and encouraging them to use them. Specialist smoking cessation treatment facilities are now a part of the National Health Service (NHS) in the UK, attracting over 500 000 smokers per year and reporting impressive cessation rates.46 Nevertheless, despite almost two thirds of smokers showing some interest in quitting, only a fraction are currently accessing the services.7

In the UK, general practitioners (GPs) are the main sources of information about the specialist smoking cessation services (SSCS). Their role has grown over the years from a focus on informing patients about the health risks of smoking, to provision of brief interventions, to referral for specialist treatment. With the exception of self-referral, the services receive more GP referrals than referrals from all other sources taken together.4 Nevertheless, there remains substantial scope for improvement. Although many GPs make good use of the services, others are not using them well or at all, or even shy away from discussing smoking with their patients.8

There are a number of possible barriers to referral, including limited knowledge of local services and the treatments they offer, uncertainty about handling questions that may follow if the issue of smoking is raised, lack of time where referrals are believed to be time-consuming, convoluted referral systems, and fear of harming the doctor–patient relationship.9 A training session to remove such barriers would have to be brief to be practicable and acceptable in routine care. The efficacy of such training in increasing referrals for smoking treatments remains to be established. Training primary care physicians in new skills is an issue of global importance. In the field of smoking cessation, training of primary care physicians can lead to measurable differences in practice (eg, recording smoking status and provision of brief advice to quit),10 11 but there is insufficient evidence to show that training physicians to provide specialist smoking cessation treatment leads to a significant increase in smoking cessation rates.12

Our trial tested the effect of a 40-min training session for GPs, focusing on the likely barriers to referral and referral skills, on the referral of patients to SSCS.



We recruited participants in general practices from three east London primary care trusts (PCTs). The participant flow is shown in fig 1. A total of 479 GPs (including part-time principals) were eligible to take part. Recruitment took place in August and September 2004. We sent study information, via fax, to all GPs with a follow-up telephone call 2 days later. GPs were asked to fax back a form indicating whether or not they wanted to take part and for those who consented to take part to estimate how many smokers they had referred to the SSCS in the last month. A second fax was sent 1 week after the first to non-responders, which was again followed 2 days later by a telephone call. In addition, the study was presented at a general practice educational meeting in two of the three PCTs.

Figure 1 Participant flowchart.

To detect an increase from the baseline referral rate of 0.6 to 2 referrals per GP over a 3-month period a minimum of 40 participants were needed in each arm (85 power, alpha  5, two-tailed test). This sample size calculation was based on an assumption of three GPs per practice and an intra-cluster correlation in referral rates between practices of 0.1.


The number of referrals from each GP was assessed by recording the referral forms received by the SSCS and counting clients who contacted the service pro-actively by telephone and reported they were referred by the study GPs. The source of referral for patients who contacted the clinic pro-actively was collected by the Smoking Cessation Service receptionist, who was not part of the study team and was blind to GP allocation in the trial. The average number of referrals per GP to the SSCS was obtained for 3-months prior to the actual training date and for 3-months after for the intervention arm. For the usual care arm, the time point from which 3-month pre- and post-study data were collected was the median date of the intervention group training. A 4-month pre- and post-comparison period was originally planned. Due to the late commencement of the study, this was reduced to 3 months.


Practices within each PCT were randomly allocated to either usual care or intervention arms using computer-generated minimisation. This was carried out by the trial statistician (SE). Minimisation variables were baseline self-reported referral rates and the number of GPs per practice.

Usual care arm

Participants were able to refer their patients to the SSCS by giving patients the local free-phone number to ring or by faxing patient’s contact details to the SSCS.

All participants were sent a supply of 10 referral forms on entering the study and again 6 weeks later. They were encouraged to request a further supply of referral forms when needed.

Two PCTs offered payment to GPs for referring smokers to the SSCS. GPs were given £1 for each faxed referral, and an additional £4 if their patient attended at least one treatment session. The third PCT ran a scheme that rewarded GPs for providing smoking cessation advice within their own practices rather than referring smokers on to the SSCS. These schemes were not in place during the 3-month baseline period and their introduction coincided roughly with the study set up.

Intervention arm

In addition to the provision available to the usual care arm described above, participants in the intervention arm were offered a 40-min training session. The content of the session was developed by the Tobacco Dependence Research Centre in collaboration with the General Practice and Primary Care Research Unit, both at Queen Mary, University of London. The session covered reasons why dependent smokers may need help in stopping and the benefits of referring them for treatment, provided an outline of what SSCS treatment offers and of its results compared to brief advice, and provided practical guidelines and taught simple skills in referring smokers for treatment. The training was delivered as an interactive presentation by two of the investigators (PH and HM) between October and December 2004. GPs attending the session received £100 to cover their time and expenses.

Statistical methods

The number of referrals was calculated for the baseline and follow-up periods (1 month, 2 months, 3 months). Differences between the arms were assessed using Poisson regression, accounting for heterogeneity between practices using a random effect for practice. The model also accounted for baseline referral levels with a dummy variable that indicated whether the baseline referral rate was zero, or greater than or equal to 1. The model also adjusts for different numbers of GPs per practice. We fitted four models, one for referrals over the whole period and one for referrals in each of the 3 months separately. We used an interaction test in the overall model to test whether the results were different at 1, 2 and 3 months. The incidence rate ratio reflects the relative likelihood of being referred in the intervention arm compared to usual care arm. Significance levels for all tests were two-tailed (alpha  0.05). Participants randomised to the intervention arm who did not attend the training session were included in the intervention arm in the intention-to-treat analysis


In total, 92 GPs from 55 practices volunteered to take part. One GP in the intervention arm went on maternity leave and could not take part in the study, leaving a total sample of 91.

A total of 28 (61) participants in the intervention arm attended one of the training sessions in the study centre and a further 13 (28) were trained in their own practices. Five (11) participants in the intervention arm were unable to attend any training.

Baseline data for referrals recorded by the service were unavailable for six participants in three practices (one in the usual care and two in the intervention arm) who previously referred to a service in an adjoining area. The mean (SD) referral rates per GP in the 3-month pre-study period were 1.0 (3.5) and 0.6 (1.5) in the intervention and usual care arms respectively.

Table 1 shows the trial results. After adjusting for other factors, the number of patients referred to the SSCS was 5 times greater among GPs in the intervention arm that the control arm (p<0.001; 95 CI 1.7 to 14.7). At an individual GP level, in the follow-up period participants from the intervention arm referred an average of 6.4 smokers each compared to 1.8 smokers from each of the participants who acted as controls. The majority of referrals were via the faxed forms (362 fax referrals, 9 phone referrals).

Table 1 Referrals received by specialist smoking cessation service after the intervention

Table 1 shows that the effect, although significant in all time periods, declined in months 2 and 3 compared to month 1.

What this paper adds

It is well known that general practitioners (GPs or primary care physicians) have an important role in helping their patients stop smoking. Where specialist smoking cessation services exist GPs are the main source of referrals to these services. This paper shows that a brief, simple and easily deliverable 40-min training session for GPs can increase the number of smokers referred for smoking cessation treatment.


A brief 40-min training session focusing on understanding the treatment provided by the NHS SSCS, and on referral skills, significantly increased patient referrals to a SSCS over 3 months of follow-up.

The effect of the intervention dropped off after the first month. The rate of decline levelled off between months 2 and 3 and the referral rates from the intervention arm remained significantly greater than rates from the usual care arm throughout the follow-up period. However, it is likely that the intervention would need to be reinforced at least once or twice for the simple referral procedure to become an automatic part of everyday practice. In routine care, smoking cessation coordinators may need to monitor GP referral rates and generate occasional reminders, feedback letters and possibly annual training updates.

The fax referral method appeared to be popular among GPs and accounted for most of the referrals. This method has been used with success in other smoking cessation services13 and can be easily implemented within primary care settings.

Several factors may limit the generalisability of the study results. Firstly the training was provided by experts in the field, unlikely to be replicated in routine primary care training, and this may have increased its impact. However, the training format is transferable and it seems likely that the response was largely due to the clear focus of the session on relevant information and skills. Also, the effect of the intervention was large and it would remain clinically significant even if considerably diluted.

Secondly, financial incentives were run by the three PCTs taking part in the study. However, as GPs were randomised within PCTs, this could not affect the study results. Participants in the intervention arm were paid £100 for their time and travel. Many PCTs currently pay GP practices for smoking cessation work, so a payment to facilitate GP attendance (for example, to pay for locum cover) at a training session with a significant impact on patient care seems equally justifiable.

Thirdly the response rate for participation in the study was low (24) although this compares favourably with rates of under 10 reported by others.14 15 Attendance at training sessions was also incomplete. In all, 28 of GPs requested that the training was delivered at their practices, and 11 were never trained. When trying to implement the intervention in routine care, this will represent a challenge. If the aim is to include the majority of GPs rather than the enthusiastic minority, the training will need to be practice-based or utilise existing opportunities such as continuing professional development sessions.

Previous studies have demonstrated that educational interventions for GPs can generate a measurable and important difference in clinical practice.16 17 The findings of this study suggest that a brief training session can improve patient referral for effective specialist programmes.


We are most grateful for the help provided by Michelle Lee and Sharon Howland in recruiting participants for this study. We are also grateful for the support from City & Hackney, Newham, and Tower Hamlets Primary Care Trusts, with particular thanks to George Leahy, David Sloan, Ian Quigley, Emma Walker and Dominick Nguyen. We would also like to thank all the general practitioners who volunteered to take part in this study. PH and HM had the original idea for the study and were responsible for design, collecting data, analysis and interpretation of data and writing the paper. GF contributed towards design, analysis and interpretation of data and writing the paper. SE performed the statistical analyses and contributed to the design and writing of the paper. PH is guarantor for the study.



  • Funding: This study was funded by a grant from Health Development Agency to the HDA/NICE Collaborating Centre. The authors’ work in design, data analysis and writing the paper was completely independent of the sponsor.

  • Competing interests: None.

  • Ethics approval:This study was reviewed by the East London and The City Local Research Ethics Committee and was granted approval on 15 July 2004.

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