S.: n=step step onestep three,689) split up because of the try sized per nation increased of the new weights

According to the complex sampling design of the GYTS, the weighted prevalence estimates and their 95% confidence intervals (CI) of smokeless tobacco use in each country were calculated using original sampling weights, strata, and pripling units provided in the datasets using the SAS PROC SURVEYFREQ procedure. The original weights were calculated by the following formula: W=W₁*W₂*f₁*f₂*f₃*f_cuatro, where W₁ is the inverse of the selection probability of each school; W₂ is the inverse of selection probability of each class; f₁ is the school-level non-response adjustment factor calculated by school enrolment size; f₂ is the class-level non-response adjustment factor for each school; f₃ is the student-level non-response adjustment factor for each class; f₄ is the post-adjustment stratification factor calculated by grade and sex. We rescaled the original weights to calculate the overall and subgroups’ prevalence of smokeless tobacco use based on each country’s sample size. The rescaled weights were calculated as the maximum country sample size (i.e., U. Chi-square trend test was used to examine the secular trend in the prevalence with consideration of data from all surveys in each country between 1999 and 2019. The prevalence estimates of secular trends were calculated per 5 calendar years. Multivariable logistic regression models were used to assess the association of potential associated factors (sex, age, cigarette smoking, other tobacco product use, parental smoking, smoking status of closest friends, tobacco advertisement exposure, being offered free tobacco products, being taught about dangers of smoking, and World Bank income level) with current smokeless tobacco use, and the code for each variable is shown in Additional file 1: Table S1. In order to correct the overall probability of type I error in multiple statistical tests (?=0.05), the Bonferroni’s correction was used to adjust the critical significance level of each statistical test. The corrected critical significance level was equal to the original critical significance level (0.05) divided by the number of tests performed. A two-sided P-value less than the Bonferroni’s corrected critical significance level was regarded as statistical significance and SAS 9.4 (SAS Institute, Cary, NC, US) was used for all analyses.

Overall performance

All in all, 450,691 adolescents (boys: 51.4%) old several–sixteen decades off 138 places interviewed ranging from 2010 and you may 2019 was basically included to imagine brand new incidence from latest smokeless using tobacco and you will their relevant facts. Certainly 138 included nations surveyed this year–2019, 23 (sixteen.7%) was indeed regarding the African part, 31 (21.7%) on American area, 23 (sixteen.7%) on the East Mediterranean part, 29 (twenty-two.5%) about Eu part, 9 (6.5%) on the South-East Far-eastern area, and you will twenty two (15.9%) throughout the West Pacific region (Even more file step 1: Desk S2).

Based on the current research from 138 nations this current year-2019, the entire prevalence out-of latest smokeless tobacco use was 4.4% (95% CI 4.0–4.9), with 5.7% (5.1–6.3) getting boys, step 3.1% (2.6–step three.5) for girls, step three.9% (step 3.5–4.4) to possess adolescents old several–14 years, and you can 5.4% (cuatro.8–5.9) for these old 15–16 decades (Dining table 1). The brand new incidence ranged rather around the all of the 138 regions (off 0.0% into the Tokelau so you’re able to 51.6% during the Kiribati), and also by gender and generation within every one of really nations (Fig. step one, and extra file 1: Fig. S2 and you may Dining table S3). The new incidence are nearly five times highest certainly one of newest cigarette smokers in contrast to non-smokers (fourteen.3% vs. step 3.0%), and almost seven times large one of other cig equipment profiles opposed having non-profiles (twenty-two.5% versus. 3.2%). The fresh new frequency one of adolescents whose both dad and mom (nine.8%), and you can mom merely (5.6%) used are more than those people whose father only (4.4%) and you may none mother or father (cuatro.7%) used. This new frequency try highest on the Southern area-Eastern Asian part (6.1%), accompanied by brand new African region (5.4%), and you may reduced regarding West Pacific part (dos.0%). The fresh incidence are large into the down-middle-money countries (5.5%), accompanied by lowest-money nations (4.7%), and you will reasonable for the high-money places (2.8%) (Table step 1).