Interventions for smokeless tobacco use cessation
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To establish the efficacy of behavioural and pharmacotherapeutic interventions to treat ST use.
Background
Smokeless tobacco (ST), which refers to moist ground tobacco and chewing tobacco, is an important worldwide public health issue. Use rates and ST preparation types vary globally. In the United States, among individuals 18 years of age or older, 6.6% of males and 0.4% of females report ST use in the last month (US DHHS 2001). In India, an estimated 22% of males use ST solely and 8% use ST and smoked tobacco concomitantly (WHO 1997). Approximately 30% of Swedish men are reported to use snus (Rodu 2002). In Sudan, about 40% of males and 10% of females use a type of ST known as toombak (Idris 1994).
The potential public health implications of the widespread use of ST are of concern. According to the 1986 report of the U.S. Surgeon General, the use of ST products can lead to nicotine addiction and physical dependence. ST use causes generalised and advanced periodontal disease, tooth decay, leukoplakia, and oral cancer (NIH 1986). ST use may increase the risk for cancer of the esophagus, larynx, stomach, and pancreas (Connolly 1986; Mattson 1989). ST use is associated with risk factors for cardiovascular disease, such as elevated blood pressure and cholesterol levels (NIH 1986; Tucker 1989; Bolinder 1992; Bolinder 1994). In laboratory rat models, ST extracts exhibit adverse effects on fetal viability and development (Paulson 1988).
Despite the widespread use of ST products and their adverse health consequences, medical and oral health professionals have neither evidence summaries nor evidence‐based guidelines to assist them in providing effective treatment for ST use. An expert review concluded that the evidence base for treating ST users was limited by small sample size and lack of control groups (Hatsukami 1997).
Objectives
To establish the efficacy of behavioural and pharmacotherapeutic interventions to treat ST use.
Methods
Criteria for considering studies for this review
Types of studies
Randomised or pseudo‐randomised controlled trials allocating smokeless tobacco users to an intervention or control, or to different interventions. We will also include trials in which dentists or other healthcare providers were randomised to provide intervention or control, and trials in which the unit of randomisation was the school, workplace or institution.
Types of participants
Users of any tobacco product that is placed in the mouth and not burned, including moist snuff, chewing tobacco and betel quid.
Types of interventions
Interventions could be pharmacologic (including for example nicotine replacement therapy (NRT) and bupropion) or behavioural, and could be directed at individual ST users or groups of users (eg ST users visiting the dentist, attending school, or working).
Types of outcome measures
The preferred outcome for the meta‐analysis will be tobacco abstinence six months or more after the start of the intervention. If total tobacco abstinence is not reported, abstinence from ST alone will be used. Trials with shorter follow‐up or not reporting quit rates will be excluded. Biochemical validation of self reported abstinence is not required, but validated rates will be used where reported.
Search methods for identification of studies
We will search the following electronic retrieval systems and databases: the Cochrane Tobacco Addiction Group specialised register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, Healthstar, ERIC, PsycINFO, National Technical Information Service database, Dissertation Abstracts Online, Database of Abstract of Reviews of Effectiveness (DARE), and Current Contents. The following terms in the search strategy will identify the use of smokeless tobacco: chewing tobacco, oral tobacco, spit tobacco, snuff, smokeless tobacco, quid, chew, and plug. The following terms described the interventions: behavior modification; conditioning therapy; therapy, behavior; therapy, conditioning; group therapy; cognitive therapy; counseling, behavioral intervention; pharmacotherapy; therapy, and drug. Terms will also include the following Medical Subject Headings (MeSH): tobacco, smokeless; behavior therapy; counseling; and drug therapy. There will be no language restrictions.
We will scan the reference lists of retrieved studies including review articles, conference proceedings, and personal reference files.
Data collection and analysis
Two authors will examine each title generated from the search and identify potentially eligible articles for which we will obtain the abstracts. For abstracts consistent with study eligibility, we will obtain the full article text. Any difference of opinion about study inclusion will be resolved by consensus. Two authors will independently extract data about participants, interventions, outcomes, and methodological quality using a standardized data extraction form. Any discrepancies in extracted data will be resolved by consensus.
We will assess study quality on one major criterion; appropriate separation between investigators deciding on participant inclusion and the process of random allocation to treatment or control (allocation concealment). Studies reporting an acceptable method of allocation concealment, for example central enrolment and allocation, or consecutive numbered sealed opaque envelopes will be marked A, studies which did not give sufficient detail to assess quality will be marked B, and studies reporting a method which did not allow allocation concealment, for example allocation on the basis of patient record number, will be marked as C. We will conduct a sensitivity analysis of the effect of including trials classified as C in a meta‐analysis. Other possible indicators of quality include: blinding status of participants, investigators, and outcome assessors; group similarity at baseline; equal treatment of groups during study conduct; completeness of follow‐up; analysis and conduct by the intention‐to‐treat principle; and use of a placebo or active intervention in the control group (Guyatt 1993). We will not formally assess the impact of differences in these criteria on the results. We will record the use of biochemical validation, and reported differences in baseline characteristics, any co‐interventions and the control intervention.
We will extract data on the numbers of users quit at the longest follow‐up, using the strictest definition of abstinence reported. Continuous or prolonged abstinence will be used in preference to point prevalence. If biochemical validation was used we will select validated rates. Participants who were randomised but dropped out or were lost to follow‐up will be assumed to be continued users. If we are not able to extract data allowing an intention to treat analysis this will be recorded.
We will use odds ratios (ORs) to represent the point estimate of the magnitude of association between intervention exposure and treatment outcomes and 95% confidence intervals (CI) to represent the precision around this point estimate. An OR greater than 1 indicates that the odds of quitting was higher in the intervention group than in the control.
We will pool results of studies when it is clinically and statistically appropriate. We will not combine pharmacotherapy and behavioural interventions, or different types of pharmacotherapy. We will conduct meta‐analyses using a fixed‐effect model, unless there was significant between‐study heterogeneity (Fleiss 1993). In the case of significant heterogeneity we will consider the results of a random‐effects model.
We hypothesize that the intensity of the behavioral interventions in terms of frequency and/or time of contacts with a health professional or study investigator would lead to different outcomes. We anticipate that longer and more frequent contacts would increase abstinence rates compared to shorter and less frequent contacts. We also hypothesize that the behavioral interventions involving recruitment of individual ST users would be associated with higher abstinence rates for intervention compared to control than those recruiting ST users at the organizational level. This is based upon the presumption that ST users receiving interventions at the organizational level (ie dental practice or athletic teams) may receive interventions although they are not actively seeking treatment for ST use.
