Risk factors leading to hospital admission in Iranian asthmatic children

Prevalence of asthma among Middle Eastern children: A systematic review

Background: The prevalence of asthma and allergy has increased during the last decades, especially in children. However, little is known about it in the Middle East region. This systematic review is aimed to estimate the prevalence of asthma among the Middle Eastern children.

Methods: Local and international scientific databases including SID, Iranmedex, Medline and Science Direct were systematically searched for relevant keywords including; asthma, prevalence, children, International Study of Asthma and Allergies in Childhood (ISACC) and the names of Middle Eastern countries for the period of 1996-2011. Papers in Persian and English which met the defined criteria were included into the study. Bibliographies of the extracted articles were also searched. After extraction of data, heterogeneity between studies and publication bias were measured using Egger's-test. Effect size was pooled by the random-effect model. Since significant heterogeneity was found between studies, univariate meta-regression analyses were done to assess the association of variables with the overall results.

Results: Fifty studies in the Middle East examined the prevalence of asthma and allergy in children under the age of 18 years according to the ISAAC criteria and were included. A total number of 289,717 children were examined in the included studies and the prevalence varied from 0.7 % in Isfahan to 22.3 % in Bagdad. The total prevalence of diagnosed asthma was calculated 7.53 % (95% Cl: 6.38-8.75). Prevalence of asthma in the 13-14 years age group was 7.57% (95% Cl: 5.78-9.29) and in 6-7 years age group was 7.43% (95% Cl: 5.75-9.10). The prevalence of asthma among girls, based on random effect model, was 6.30% (95% Cl: 4.97-7.61) and among boys, it was 8.91% (95% Cl: 6.80-11.04).

Conclusion: The prevalence of asthma in the Middle East is lower than most developed countries. However, there is not enough longitudinal data to estimate the trend over time. In order to have more accurate estimates and to provide evidence for proper planning, standard epidemiologic studies should be conducted in countries of the region.

Serum total IgE levels and total eosinophil counts: relationship with treatment response in patients with acute asthma

OBJECTIVE

To determine whether serum total IgE levels and total eosinophil counts have any relationship with the response to routine pharmacological treatment in patients with acute asthma.

METHODS

A cross-sectional study involving 162 patients with acute asthma. Serum total IgE levels, peripheral blood cell counts and eosinophil counts were determined. The treatment was adjusted for each patient according to the severity of asthma. Spirometry was performed at baseline and two weeks after the treatment. The patients were divided into two groups: high IgE (>100 IU/mL) and low IgE (<100 IU/mL). We compared the two groups in terms of the relationships between baseline values and final values (percentage change) for the following parameters: FEV1, FVC, FEF25-75%, peripheral white blood cell counts and eosinophil counts.

RESULTS

There were no significant differences between the groups regarding the percentage changes of the studied parameters. Nor were there significant differences between the groups regarding FEV1, FVC, and FEF25-75% (% of the predicted values) at baseline.

CONCLUSIONS

On the basis of these findings, we conclude that serum total IgE levels, peripheral white blood cell counts and eosinophil counts cannot predict the response to the pharmacological treatment of patients with acute asthma.

A systematic review of recent asthma symptom surveys in Iranian children

Asthma is the most prevalent chronic disease in children. To quantify the national prevalence of asthma symptoms in Iranian children, we conducted a systematic review and meta-analysis. After internet and hand searching for population-based prevalence estimates published from 1998 to 2003 from 142 articles, dissertations and reports of research projects, 19 of them were selected. All the selected studies on children had been performed by the International Study of Asthma and Allergies in Childhood (ISAAC) protocol. We analyzed the data using NCSS software. In the included 19 studies, 61,067 children in different age groups had been examined by the ISAAC protocol. The lowest prevalence of asthma symptoms was 2.7% in Kerman and the highest was 35.4% in Tehran (capital of Iran). Overall prevalence of asthma symptoms at a national level was estimated as 13.14% (95% CI: 9.97-16.30%). Based on this study, the prevalence of asthma symptoms in Iran is higher than that estimated in the international reports. This information can be used to help prioritize asthma prevention and control within the range of Iranian public health concerns.