Background: There is evidence that the worldwide prevalence of asthma is increasing, particularly in children.
Objective: To compare the cumulative prevalence of medical diagnosis of asthma among Mexican schoolchildren in two surveys 12 years apart.
Material and methods: The study populations of the two comparable cross sectional surveys comprise six to twelve years old public and private schoolchildren in Villahermosa, Tabasco, Mexico. Sample sizes in 1986 and 1998 were 6,465 and 6,073 children and response rates were 72 and 85%, respectively. The sampling frame and sampling method were identical in both surveys. The prevalence of medical diagnosis was expressed by sex and age comparing 1986 to 1998. An analysis of contingency tables was used to asses the differences in the prevalence rates.
Results: Cumulative prevalence of medical diagnosis of asthma in 1986 and 1998 were 8.74 and 12.63%, respectively, 45% of increase. We found a significant increase in lifetime of asthma (p = 0.001). The observed increases were independent of sex and age.
Conclusion: As it has come to pass all over, our results support a significant increase in the cumulative prevalence in the last 12 years among schoolchildren in Villahemosa, Tabasco, Mexico.