Only the first baseline biomarker value from each participant was analyzed unless it was missing, in which case the second baseline biomarker value was substituted if available. To ensure validity of the analyses, biomarkers were transformed selleck chem Cisplatin using the natural logarithm to approximate normality and were summarized using geometric means. To compare each of these factors by flavor while adjusting for study differences, mixed-effects analysis of variance models were fit with flavor (yes, no) as a fixed effect and a random effect for individual study. Models additionally adjusting for years of regular use were considered. Analyses were carried out in SAS v. 9.2 (SAS Institute, Inc., Cary, NC) and all significance levels were set at 0.05. Results A total of 468 subjects had current brand-flavor information for this analysis.

Table 1 shows the type of mint flavors used by the ST users during the progression from first product used to first daily product used to current product used. Approximately 60% used a mint-flavored product as their first product used or product that they first used regularly or daily. A similar percent reported current use of flavored products. The majority of the flavored-product users favored wintergreen flavors. Table 1. Flavors Across Smokeless Tobacco Use Spectrum (n = 468) Figure 1 shows first and current product use by flavor. Of the ST users who started using mint-flavored products, 64.4% reported current use of flavored products whereas 48.7% of those who started using nonflavored products continued to use nonflavored products.

Of those who first used nonflavored products, 51.3% indicated switching to a flavored product as their current product. Of those subjects first using flavored products, 35.6% of ST users switched to a nonflavored product as their current product. Those ST users who started by using nonflavored products were more likely to switch to mint-flavored products compared with the other way around (p < .0001). ST users who started with a mint-flavored product were also more likely to currently use a mint-flavored product compared with those who continue with nonflavored products (p = .001). Figure 1. Comparison of first and current product use by flavor (n = 6 missing first smokeless tobacco product). Table 2 shows the results comparing the demographics, ST use history, and biomarkers of exposure between ST users using nonflavored versus mint-flavored products.

ST users of flavored products were significantly younger in age (32.5 vs. 37.3 years; p < .0001), used fewer dips per day (8.8 vs. 9.9; p = .035) and had fewer years of regular use (13.0 vs. 17.8 years; p < .0001). As expected, age and years of Dacomitinib regular use were highly correlated (Pearson correlation coefficient = .72, p < .0001). ST users of flavored products also had lower cotinine levels (p = .