Information Growth at Subsequent Levels of the Estimation Process

This infographic represents the statistical methods we used to estimate the global number of vapers in 2020 (see p.156 of the GSTHR report Burning Issues: The Global State of Tobacco Harm Reduction 2020). Based on the available information, we calculated the average prevalence of vaping for the WHO region, World Bank income classifications and legal status of the sale of e-cigarettes. Unfortunately, as we could guess, some groups are very poorly represented. Low-income countries are represented only by Uganda. Uganda is also the only data point for the African region. Similarly, we have only one data point from the South East Asia region with Bangladesh and the East Mediterranean region with the United Arab Emirates.

These three factors gave us four income groups, six regions and three sales statuses, which allowed us to separate 72 subgroups. For each of the groups the average prevalence of vaping was calculated. These 72 values were used as substitutes for the prevalence figures in the countries belonging to the group. Of course, not all subgroups were represented. For the first (1) – the most detailed, three-factor – subdivision we had information for only 13 subgroups, which allowed us to calculate estimates for 83 countries.

For the other countries, we had to use a two-factor breakdown covering all pairs of these three factors. A second (2) split was made on the basis of income groups and sales status, which gave us eight information cells covering 161 countries, a third (3) was made on the basis of income groups and regions with 10 information cells covering 142 countries and a fourth (4) was made on the basis of regions and sales status with nine information cells covering 102 countries. Last (5) subdivision was only based on one income groups factor.

The results of the calculations have been placed successively in the blanks remaining after the previous step. This means that the countries remaining without an estimated value after the first step have been assigned the values generated in the second step. In the third step we filled in the missing values remaining after the second step and in the fourth step remaining after the third step. All remaining gaps were filled with the fifth step.

We started with 49 known countries. The first step increased this number to 83, the next to 161, next to 190, the fourth one gave us only three more countries, increasing the number of countries to 193, and the fifth to 198. There were still three countries left. We attributed the average value obtained from all known countries to these countries.

See also p.151 of the report: Burning Issues: The Global State of Tobacco Harm Reduction 2020