[Prevalence of asthma in Cuban adolescents by different clinical criteria]

BACKGROUND

Despite of the knowledge about asthma, its diagnosis is clinical and its prevalence depends on the case criterion. Several methodologies have been applied to determine its prevalence; the International Study of Asthma and Allergies in Childhood (ISAAC) is the newest, although some inconsistencies have been attributed to their results.

OBJECTIVE

To estimate the prevalence of asthma according to five diagnostic criteria and according to respiratory symptoms in order to contribute to improve the diagnosis quality.

MATERIAL AND METHODS

Data of the first phase of the ISAAC study made at the Centro Cubano Playa-Marianao in 2003 were collected. Three thousand twenty-six children of 13 to 14 years of age answered a survey, and prevalence of established criteria was estimated; confidence intervals were used to compare them. Estimations were presented with 95% of confidence; the chi square test and the odds ratio were applied for prevalence rates by gender.

RESULTS

When comparing all the prevalences among different criteria, those corresponding to criteria I and II were statistically significant. Criterion I was the least discriminatory and criterion V had the highest power to discriminate. Criterion III offered an intermediate value of prevalence, with a proper level to discern. The first three criteria had higher prevalences in women, with statistically significant values among genders (p = 0.002, p = 0.045 and p = 0.008, respectively).

CONCLUSIONS

Using a criterion that could include several symptoms, especially in low income-countries, where hospitals do not have current and expensive diagnostic methods, would be useful and would contribute to diminish the diagnostic error.