Evaluation of biochemical validation measures in determination of smoking status

Brief supportive telephone outreach as a recruitment and intervention strategy for smoking cessation

BACKGROUND

Formal efforts to recruit smokers into cessation programs have failed to reach large segments of the smoking population. Telephone intervention may represent a viable strategy to promote smoking cessation. An even more promising approach may be a combination of brief telephone support and outreach to identified smokers.

METHODS

Telephone support for smoking cessation was provided to four identified smoker populations in Bloomington, Minn, one of three Minnesota Heart Health Program education communities. Smokers were randomly assigned to an intervention consisting of two 15-minute telephone calls approximately 1 to 3 weeks apart or to a nonintervention control.

RESULTS

At the 6-month follow-up, a significant overall effect was found in favor of the intervention condition for both self-reported and cotinine-validated quitting. Differences between intervention and control conditions were no longer significant at 18 months.

CONCLUSIONS

Smokers' receptivity to telephone intervention was at least moderately encouraging. The cost of intervention could be relatively low if trained volunteers initiated telephone calls. However, more intensive telephone intervention and support may be needed to produce lasting changes in smoking prevalence.

Evaluation of two biological markers of tobacco exposure. MRFIT Research Group

This study assesses serum thiocyanate and expired-air carbon monoxide based on findings for 8,895 participants in the Multiple Risk Factor Intervention Trial. For each marker and combination of markers, a logistic probability model was used to generate a plot of true positive vs false positive rates (an operating characteristic curve), an optimal cutpoint, and the positive predictive value for discriminating tobacco smokers (cigarettes, pipes, cigars, or cigarillos) from non-tobacco smokers. Optimal cutpoints were 83 mumols/liter for thiocyanate and 10 ppm for carbon monoxide. These cutpoints were applied to the entire group to evaluate accuracy. Specificity was higher for carbon monoxide than for thiocyanate (91.8 vs 87.3%) and sensitivity was lower (85.7% for carbon monoxide vs 88.8% for thiocyanate). When carbon monoxide and thiocyanate were both used, specificity was 92.7% and sensitivity was 89.1%. The estimated cutpoints derived from the Multiple Risk Factor Intervention Trial result in predictive values greater than 87% when the prevalence of smokers is greater than 50%. Cutpoints should be modified to maximize the predictive value when the prevalence of smokers is less than 50%. Both serum thiocyanate and carbon monoxide are good markers of smoking exposure. Serum thiocyanate may be preferable to carbon monoxide because of its longer half-life.

Measurement of salivary thiocyanate during the process of smoking cessation

The changes in salivary thiocyanate (SCN) following smoking cessation were determined for 70 people recruited from community-based smoking cessation programs. Data collected over 3 months following cessation showed a half value of 5 days for abstainers, a strong linear relationship between SCN level and number of days since quitting, and considerable individual variation in precessation SCN level. It is concluded that SCN has value as an inexpensive, initial screening test of smoking behavior.

Induction of nuclear aberrations by smokeless tobacco in epithelial cells of human oral mucosa

Cytologic and cytogenetic studies were performed to assess the prevalence of somatic cell genetic damage in 48 young adults equally divided to represent users and nonusers of smokeless tobacco. Exposure was ascertained by measuring saliva cotinine using capillary gas chromatography. Squamous epithelial cells sampled from the oral mucosa demonstrated significant cytologic alterations associated with tobacco exposure. The frequency of micronucleated cells was significantly (P less than .01) higher in the labial mucosa of exposed (2.22%) compared to unexposed (0.27%) individuals. The frequency of micronuclei varied widely between exposed subjects but was higher in heavily (2.48%) compared to lightly (1.29%) exposed individuals as measured by saliva cotinine levels. Morphologic classification of epithelial cell nuclei showed that the frequency of cells with normal nuclear structure was significantly (P less than .01) reduce in exposed individuals. Analysis of oral epithelial cells of five additional nonusers of smokeless tobacco but wearers of orthodontic appliances to stimulate abrasion demonstrated no difference from the nonexposed control group. Unlike the case with cigarette smokers, peripheral lymphocyte sister-chromatid exchange frequency was not affected by exposure to smokeless tobacco. The oral cytology data, however, support an interpretation of exposure-dependent nuclear alterations, including micronuclei, in the oral epithelium associated with the use of smokeless tobacco. Altogether, results suggest that use of smokeless tobacco may cause genetic damage to cells in the oral epithelium.

Caries on root surfaces exposed following gingivectomy in conventional rats infected with Streptococcus sobrinus and Actinomyces viscosus

To study the ability of bacteria associated with coronal caries to initiate root surface caries, a rat model was used. Root surfaces were exposed by gingivectomy in rats fed a caries-promoting diet and orally inoculated with either Actinomyces viscosus M-100, Streptococcus sobrinus (mutans) 6715, or both. A fourth group received a diet containing antibiotics. The animals were sacrificed 64 days following the gingivectomy performed on the right molar quadrants. Gingivectomy significantly increased exposed lingual root length and root caries incidence. There were no caries on non-gingivectomy root surfaces. Root surface caries incidence in the groups inoculated with A. viscosus and A. viscosus plus S. sobrinus did not differ. For both these groups, root caries incidence was significantly greater than that for the group inoculated with S. sobrinus alone. Root caries incidence in this latter group did not differ from that in the control group.

Helping smokers quit: a randomized controlled trial with private practice dentists

Fifty private practitioners and their office staff members were randomly assigned to one of four groups: participants received a protocol for smoking management and a lecture on the consequences and management of smoking, or in addition, had nicotine gum freely available to patients, had stickers attached to their charts, or had gum and reminders. The percentage of patients in each group who had quit smoking a year later was 7.7, 16.3, 8.6, and 16.9, respectively, indicating a significant main effect for the gum conditions. The availability of nicotine gum also significantly increased the amount of time that patients reported they received smoking cessation counseling from the dentists and office staff.

The effects of different levels of dietary sucrose on root caries subsequent to gingivectomy in conventional rats infected with Actinomyces viscosus M-100

Three groups of weanling, Sprague-Dawley-derived rats were inoculated with Actinomyces viscosus M-100 and fed powdered diet containing either 67%, 5%, or 0% confectioner's sugar. Two further groups were fed diet containing 5% confectioner's sugar and inoculated with Streptococcus sobrinus 6715 or S. sobrinus 6715 plus A. viscosus M-100. The most coronal 1 mm of gingiva was removed from maxillary and mandibular right molar quadrants (gingivectomy), and the animals re-inoculated following gingivectomy. The animals were killed 64 days following gingivectomy, and the lingual surface of mandibular first molar roots was measured for exposed root-surface area and root caries. In the groups of rats infected with A. viscosus M-100, root caries area was significantly greater in the group fed diet containing 67% confectioner's sugar. Sucrose level did not significantly affect the amount of exposed lingual first molar root area regardless of whether the tooth had been subjected to a gingivectomy. In the groups of rats receiving diet containing 5% confectioner's sugar, there were no significant differences in root caries area or exposed root-surface area, regardless of the infection status of the animals. In the rat model presented here, a high level of dietary sucrose was a necessary condition for the initiation of root caries in the absence of other readily fermentable carbohydrates.

Overreporting of smokeless tobacco use by adolescent males

This study evaluates the impact of a pipeline assessment (salivary cotinine determination) on the accuracy of self-reported use of cigarettes and smokeless tobacco by 160 rural seventh- and eighth-grade males ranging in age from 12 to 16. Half of them were randomly assigned to complete a questionnaire on tobacco use prior to revealing the biochemical validation materials and collecting samples. The others had the samples collected prior to receiving and completing the questionnaires. The questionnaire-first group reported significantly greater smokeless tobacco use than did the pipeline-first group. Only for the latter were their self-reports significantly corroborated by the cotinine results. These results suggest that the utilization of a biochemical pipeline not only can improve self-reported tobacco use but also may help identify perceptions about the social desirability of using harmful substances.