Health effects and dependency associated with snuff consumption
This is an excerpt from the full technical report, which is written in Norwegian. The excerpt provides the report’s main messages in English. N0. 06–2005 Systematic reviews Title Health effects and dependency associated with snuff consumption Norwegian title Virkninger av snusbruk Institution Norwegian Knowledge Centre for the Health Services (Nasjonalt kunnskapssenter for helsetjenesten) John-Arne Røttingen, Director Authors Inger Natvig Norderhaug, Research manager Erik Dybing, Hans Gilljam, Petter O. Lind, Karl Erik Lund, Jørg Mørland, Birgitta Stegmayr, Bjørn Hofmann, Ida-Kristin Ørjasæter Elvsaas
ISBN 82-8121-051-6 ISSN 1503-9544 Report No. 6 – 2005 Project number 5-207 Type of report Systematic reviews No. of pages 133 Client The Norwegian Directorate of Health Subject heading Tobacco, Smokeless; Dependency (Psychology) (MeSH) Keywords Snuff Citation Norderhaug IN, Dybing E, Gilljam H, Lind P O., Lund KE, Mørland J, Stegmayr B, Hofmann B, Ørjasæter Elvsaas I-K. Health effects and dependency associated with snuff consumption. Report from Kunnskapssenteret no. 6−2005. Oslo: Norwegian Knowledge Centre for the Health Services, 2005.
Norwegian Knowledge Centre for the Health Services summarizes and disseminates evidence concerning the effect of treatments, methods, and interventions in health services, in addition to monitoring health service quality. Our goal is to support good decision making in order to provide patients in Norway with the best possible care. The Centre is organized under The Norwegian Directorate for Health, but is scientifically and professionally independent. The Centre has no authority to develop health policy or responsibility to implement policies.
We would like to thank all contributers for their expertise in this project. Norwegian Knowledge Centre for the Health Services assumes final responsibility for the content of this report.
Norwegian Knowledge Centre for the Health Services Oslo, June 2005
9. English summary
Background During the past ten years the sale of snuff in Norway has increased, while the sale of smoking tobacco has declined. This has happened parallel to the introduction of smoking restrictions in public areas and growing concern about the health risks associated with smoking. Approximately 300,000 used snuff in 2003/2004. Of these about 140,000 used snuff every day. The majority of snuff users are men under 45 years. The age at starting is decreasing. Female users are still few, but the number is expected to rise. Situations where the consumption rises and the health effects are not clarified, generates new challenges.
Objectives To systematically review, assess and summarize the epidemiological evidence concerning the health effects and dependency associated with snuff consumption, and the role of snuff in smoking initiation and smoking cessation.
Search strategy Systematic search was undertaken in the Cochrane Library (Cochrane Database of Systematic Reviews, DARE, CENTRAL (earlier Cochrane Controlled Trials Register), HTA (INAHTA)), Medline, Embase, Psycinfo, Cinahl, Swemed, Current Controlled Trials, from 1872 to 7 February 2005. References of identified trials and relevant reviews were also screened.
Selection criteria Epidemiological studies were selected if they were systematic reviews, randomised controlled trials, controlled trials, cohort studies or case-control trials, if they included users of snuff or smokeless tobacco, and measured one of the following: nicotine absorption, toxin exposure, mortality, cancer, cardiovascular effects, diabetes, pregnancy outcomes, oral health, dependence, smoking initiation, smoking cessation (or their synonyms).
An evaluation was not performed of documentation from animal experiments with snuff or components of snuff. The member of the expert group Erik Dybing disagrees that documentation from animal experiments was not included as a basis for the group’s conclusions.
Data collection and analysis The literature search gave 1040 hits. Two authors independently screened the abstracts, reviewed 207 publications in full text, and assessed the methodological quality of 59 studies using the Norwegian Knowledge Centre for Health Services’ checklists. 29 studies were excluded due to irrelevant problem formulation, outcome or study design.
Because the study population, interventions and outcome measures were heterogeneous, a rating system with level of evidence was used. Scandinavian and American studies were assessed separately due to reported differences in some harmful constituents of snuff products sold in Scandinavia and USA.
Main results A systematic review was carried out on the 30 studies that met the inclusion criteria. All the studies were of high or medium methodological quality. Many of the studies however
59 included few individuals who exclusively used smokeless tobacco, and combined use of smokeless tobacco and cigarettes appeared frequently. In addition, information about exposure duration and dose was often lacking.
There was overall limited epidemiological evidence of health effects associated with smokeless tobacco. There was strong evidence that smokeless tobacco produces dependency. There was conflicting evidence about smokeless tobacco and its role in smoking initiation and smoking cessation.
Conclusions Nicotine is absorbed rapidly into the bloodstream and to the same degree as when smoking.