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*fcuatro, 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 https://datingmentor.org/tr/tarihleme/ 9.4 (SAS Institute, Cary, NC, US) was used for all analyses.
Abilities
A maximum of 450,691 adolescents (boys: 51.4%) aged twelve–sixteen age out of 138 nations interviewed ranging from 2010 and you can 2019 was in fact included to help you estimate this new incidence out of latest smokeless tobacco use and you can its associated circumstances. Certainly 138 integrated nations interviewed this current year–2019, 23 (16.7%) was indeed about African region, 30 (21.7%) from the American part, 23 (sixteen.7%) on East Mediterranean area, 31 (twenty-two.5%) about European area, nine (six.5%) in the Southern area-Eastern Asian area, and you may twenty-two (15.9%) about Western Pacific area (More document step 1: Desk S2).
In line with the current research of 138 regions this season-2019, all round prevalence out of most recent smokeless cigarette smoking was cuatro.4% (95% CI 4.0–4.9), which have 5.7% (5.1–six.3) for people, 3.1% (2.6–step three.5) for females, step 3.9% (step three.5–cuatro.4) getting adolescents old several–fourteen ages, and you may 5.cuatro% (cuatro.8–5.9) for these aged 15–sixteen many years (Desk step one). New incidence ranged significantly across the every 138 nations (from 0.0% into the Tokelau in order to 51.6% when you look at the Kiribati), by intercourse and you can age bracket contained in this each of really countries (Fig. step 1, and additional file 1: Fig. S2 and Desk S3). The brand new frequency are nearly 5 times large certainly one of most recent smokers weighed against low-cigarette smokers (fourteen.3% versus. step 3.0%), and you will almost seven minutes large certainly other cigarette product users opposed that have low-profiles (twenty two.5% vs. step 3.2%). The newest frequency one of adolescents whoever both parents (9.8%), and you can mother just (5.6%) used is actually more than men and women whose dad merely (4.4%) and none parent (cuatro.7%) smoked. The latest prevalence are higher in the Southern-Eastern Far eastern area (six.1%), with this new African part (5.4%), and you can lowest about West Pacific region (2.0%). The brand new incidence are large inside straight down-middle-income nations (5.5%), with reduced-income regions (cuatro.7%), and you can reasonable for the higher-money places (2.8%) (Desk step 1).
