Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Meta-analysis: Nicotine replacement therapy is effective for reducing smoking

ACP J Club. 1996 Nov-Dec;125:70. doi:10.7326/ACPJC-1996-125-3-070


Source Citation

Silagy C, Mant D, Fowler G, Lancaster T. The effect of nicotine replacement therapy on smoking cessation. Tobacco Addiction Module of the Cochrane Database of Systematic Reviews [updated 3 June 1996]. Available in the Cochrane Library; Issue 2. Oxford: Update Software; 1996. [PubMed ID: 10796494]


Abstract

Objective

To determine whether nicotine replacement therapies (NRTs) (chewing gum, transdermal patches, nasal spray, or inhalers) are effective in achieving abstinence from smoking.

Data sources

Randomized controlled trials were identified using electronic databases (MEDLINE, Cancerlit, PsycInfo, Dissertation Abstracts, Health Planning and Administration, Social Scisearch, and Smoking and Health). Search terms used were smoking and smoking cessation with randomized controlled trial, prospective, random allocation, or double-blind method. Bibliographies of review articles and trials and lists of conference abstracts were reviewed, 2 journals were searched manually, and manufacturers of NRTs were contacted.

Study selection

Trials were selected if they compared NRT with placebo or another NRT, study duration was ≥ 6 months, and smoking cessation was formally assessed.

Data extraction

Data were extracted on patients studied, their nicotine dependency, and smoking cessation rates.

Main results

46 trials evaluated nicotine gum, 20 evaluated patches, 3 evaluated nasal spray, and 1 evaluated an inhalation product. At 12 months, 1273 patients (19%) who received nicotine gum had quit smoking compared with 966 patients (11%) who did not receive gum (P < 0.001). {The weighted absolute risk improvement (ARI) of 6% means that 17 patients would need to be treated (NNT) with nicotine gum to have 1 additional person stop smoking, 95% CI 13 to 24). The relative risk improvement (RRI) was 47%, CI 36% to 59%.}* 542 patients (16%) who received the nicotine patch had quit smoking compared with 237 patients (9%) who did not receive the patch (P < 0.001) {weighted ARI 6%, NNT 16, CI 12 to 21; RRI 85%, 60% to 114%}.* 87 patients (24%) who received intranasal spray had quit smoking compared with 39 patients (11%) who did not receive intranasal spray (P < 0.001) {weighted ARI 13%; NNT 8, CI 5 to 14; RRI 118%, CI 54% to 209%.}* The results did not differ for patches used for 16 or 24 hours/d, duration of NRT therapy, stopping that occurred through tapering or weaning compared with abrupt stopping, high-dose compared with low-dose NRT, clinical setting, or clinic patients compared with volunteer patients. (Volunteer patients, however, had a higher absolute quit rate.)

Conclusion

Nicotine replacement therapies (chewing gum, transdermal patch, and intranasal spray) are effective for long-term smoking cessation in motivated smokers.

Sources of funding: Imperial Cancer Research Fund and Royal College of General Practitioners.

For article reprint: Dr. C. Silagy, Department of General Practice, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia. FAX 61-8276-3305. E-mail mncs@flinders.edu.au

*Numbers calculated from data in article.


Commentary

Silagy and colleagues have provided an excellent overview of randomized controlled trials that used NRT (gum, patch, and nasal spray) for smoking cessation with ≥ 6 months of follow-up. Their findings are consistent with those of another recent meta-analysis of smoking cessation treatments (1) and a recent cost-effectiveness analysis (2).

As happens with many new drugs, the initial NRT efficacy studies that used motivated, healthy volunteers had greater success than the subsequent effectiveness studies that used less motivated patients in primary care settings. Now that the patch and gum are available over the counter in the United States, the absolute success rates of over-the-counter use will probably be even lower. Better success rates, however, can be expected if physicians provide more behavioral support and several months of medication (at least 6 to 8 weeks) and if patients are especially motivated or have low nicotine dependence. The nicotine spray and inhaler appear promising, but not enough data are available to determine whether they are more effective than the gum or patch. Some of the early evidence suggests that combinations of NRT may be effective, such as the patch plus gum or letting a smoker choose the type of NRT. We should remember that these studies also provided the smoker with a quit date and included some self-help material or brief counseling on smoking cessation.

Although nicotine replacement is effective, with an NNT ranging from 8 to 17, most of the treatments will fail. In the outpatient clinic, I recommend a stepped-care approach: 1) Instruct motivated patients to use a quit date; 2) if he or she is still smoking, use NRT plus a quit date; and 3) if the patient is still smoking, refer to a comprehensive behavioral program, if available, or repeat combination NRT plus quit date until successful.

Eric C. Westman, MD, MHS
Durham Veterans Affairs Medical Center and Duke UniversityDurham, North Carolina, USA


References

1. The Smoking Cessation Clinical Practice Guideline Panel and Staff. The Agency for Health Care Policy and Research Smoking Cessation Clinical Practice Guideline. JAMA. 1996;275:1270-80.

2. Fiscella K, Franks P. Cost-effectiveness of the transdermal nicotine patch as an adjunct to physicians' smoking cessation counseling. JAMA. 1996;275:1247-51.