Measuring Smoking Prevalence in a Middle Income Nation: An Examination of the 100 Cigarettes Lifetime Screen.

INTRODUCTION: Public health surveillance of smoking prevalence is essential in gauging the magnitude of the problem, identifying groups most affected, and evaluating polices. However, little attention has focused on how prevalence is measured, particularly in low-and middle-income countries, where smoking patterns may not mirror those in high-income countries and where the burden of tobacco use is rapidly growing. Mexico provides a unique opportunity to gauge how the questions used to define established smokers can affect prevalence estimates. This study assesses how using the 100-cigarette lifetime question to define smoking status affects estimates of smoking prevalence.
METHODS: We consider data from four nationally representative surveys in Mexico, from 2002 to 2016. These surveys ask about current smoking even for adults who do not indicate having smoked 100 cigarettes in their lifetime. We compare estimates of daily and nondaily smoking prevalence by age and gender with and without the 100-cigarette screen.
RESULTS: The relative difference in prevalence estimates with and without the screen was greater for nondaily than daily smoking and for females than males. The difference was especially pronounced for nondaily smokers aged 15-24, where there was a 50%-75% relative difference in estimates, albeit smaller discrepancies (20-49% relative difference) were also found among older smokers. In recent years, the relative difference was greatest at lower levels of educational attainment.
CONCLUSIONS: With the growth in nondaily smoking, using the 100-cigarettes screen to define smoking status can have important implications regarding size of smoking population. Further research is warranted in other countries.