Asthma, understood as cough, dyspnea and wheezing, is the most common disease in childhood,1 with around 300 million individuals estimated to be affected world-wide.2 It generates enormous healthcare costs, causes loss of work productivity among adults, and deeply impacts lives of families with an asthmatic child.3
Asthma is an underdiagnosed and undertreated disease, so standardized questionnaires that evaluate symptoms consistent with asthma as disease markers have become the tool of choice for the identification of asthma in descriptive studies.4,5 The ISAAC questionnaire has been used to determine the prevalence of asthma in all such studies and has contributed valuable data. The prevalence of asthma is known from these studies to be as high as 11.7% in children and 14.1% in adolescents.5
In Navarre, a study conducted in 20156 found a prevalence of asthma of 10.1% among children and 10.6% among adolescents. However, children had a higher prevalence of “wheezing at any time” than adolescents (22.7% vs 12.9%, respectively). This study was performed in a metropolitan area of Pamplona, an urban district with towns of at least 10000 inhabitants. No studies have been previously conducted in childhood asthma in Navarre. In Galicia, a study performed in 2010 in a rural population of children and adolescents7 showed that the prevalence of asthma in children and adolescents was 6.3% and 15.3%, respectively.
In the 6- to 7-year age group, 38% had had wheezing at any time, and 13.2% had recent wheezing. Recent cough at night was detected in 21.9%, and recent wheezing during exercise in 6.3%. In the 13- to 14-year age group, 20.1% had had wheezing at any time, and 11% had recent wheezing. Taking these data into account, the aim of our study was to determine the prevalence of symptoms consistent with asthma in rural areas of Navarre, and to contribute new data to the ISAAC study.
The validated version of the ISAAC study questionnaire in Basque and Spanish was used in the study, depending on the linguistic model of the school in which it was administered (Annex I). Seven Basic Health Areas (BHA) in central Navarre were selected because they contained 2 towns of approximately 10000 inhabitants (Tafalla and Estella) and were close to the workplaces of the investigators (the 15 towns are widely dispersed and each school had to be visited on several occasions). Schoolchildren aged between 6 and 7 years and 13 and 14 years attending the schools in these areas were selected.
Firstly, towns within the BHA that had schools were identified. In total, 19 schools located in 15 towns participated in the study, although these schools catered for children from a total of 45 different localities. This is because some villages have as few as 34 inhabitants.
In Spain, school attendance is obligatory between the ages of 6 and 16 years, so these schools gave us access to 100% of the study population.
To administer the questionnaires to the 2 age groups, an email containing a description of the study and requesting a meeting with the principal was sent to each school. In this way, each school decided voluntarily to participate in the study. The school principal obtained the approval of the school board and the parent-teacher association to participate in the study. Mothers and fathers also signed a form authorizing the questionnaire to be administered to their children.
Field work was carried out between September 2014 and February 2015.
Each questionnaire was scanned and the data were entered in the SPSS® statistical program to determine the prevalence of asthma symptoms by age group and sex, using the following statistical methods: 95% confidence interval (CI), Chi-squared test, adjusted analyses, odds ratio (OR), and unconditional logistic regression.
A total of 969 questionnaires were distributed: 607 (62.6%) to the 6- to7-year age group and 362 (37.4%) to the 13- to 14-year age group. In the 6- to 7-year group, 449 of the 607 questionnaires for parents were completed (74%). In the 13- to 14-year age group, 348 of the 362 questionnaires distributed were completed (96.1%). The final study population consisted of 797 schoolchildren. Distribution by age groups was: 449 (56.3%) in the 6- to 7-year group and 348 (43.7%) in the 13- to 14-year group; and by sex: 414 (52%) boys and 383 (48%) girls.
Descriptive data on the prevalence of symptoms of asthma by age group and sex are shown in Table 1.
Prevalence of symptoms consistent with asthma by age group and sex.
| 6–7 years | 13–14 years | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Boys, n: 231 | Girls, n: 207 | P-value | OR (95% CI) | Boys, n: 169 | Girls, n: 167 | P-value | OR (95% CI) | |||||
| % | 95% CIa | % | 95% CI | % | 95% CI | % | 95% CI | |||||
| Wheezing at any time | 18.3 | 13.3–23.2 | 16.2 | 11.2–21.2 | 0.942 | 1 (0.7–1.5) | 6.7 | 2.9–10.5 | 7.3 | 3.3–11.2 | 0.733 | 0.9 (0.5–1.7) |
| Recent wheezingb | 10.2 | 6.3–14.1 | 11.8 | 7.4–16.2 | 0.317 | 0.7 (0.3–1.4) | 11.8 | 6.9–16.7 | 6.7 | 2.9–10.5 | 0.548 | 0.8 (0.3–1.8) |
| Recent wheezing attacks | 0.929 | |||||||||||
| 1–3 | 16.8 | 12.0–21.6 | 13.1 | 8.5–17.7 | 11.9 | 7.0–16.8 | 11.9 | 7.0–16.8 | 0.805 | |||
| 4–12 | 3.7 | 1.3–6.1 | 4.7 | 1.8–7.6 | 2.4 | 0.09–4.7 | 3.6 | 0.8–6.4 | ||||
| More than 12 | 5.6 | 2.6–8.6 | 5.6 | 2.5–8.7 | 17.9 | 12.1–22.4 | 14.3 | 0.9–19.6 | ||||
| Wakes due to recent wheezing | ||||||||||||
| At least 1 night a week | 8.3 | 4.7–11.8 | 9.2 | 5.3–13.1 | 0.852 | 2.3 | 0.04–4.6 | 8.1 | 4.0–11.2 | 0.184 | ||
| 1 or more nights a week | 4.6 | 1.9–7.3 | 3.7 | 1.1–6.3 | 17.4 | 11.7–23.1 | 14 | 8.7–19.3 | ||||
| Recent severe wheezing | 2.9 | 0.7–5.1 | 3.9 | 1.3–6.5 | 0.656 | 0.7 (0.1–3.3) | 6.5 | 2.8–10.2 | 3.2 | 0.5–5.9 | 0.438 | 2 (0.3–11.8) |
| Asthma at any time | 5.6 | 2.6–8.6 | 6.3 | 3.0–9.6 | 0.384 | 0.8 (0.4–1.4) | 6.2 | 2.6–9.8 | 7.1 | 3.2–11.0 | 0.578 | 0.8 (0.4–1.6) |
| Recent wheezing during exercise | 3.7 | 1.3–6.1 | 2.1 | 0.1–4.0 | 0.242 | 1.6 (0.7–3.8) | 5.6 | 2.1–9.1 | 9 | 4.7–13.3 | 0.087 | 0.6 (0.3–1.1) |
| Recent cough at night | 12.8 | 8.5–17.1 | 10.7 | 6.7–14.7 | 0.802 | 1.1 (0.7–1.7) | 9 | 4.7–13.3 | 11.1 | 6.3–15.9 | 0.360 | 0.8 (0.4–1.3) |
CI: confidence interval; OR: odds ratio.
In this study, data on the prevalence of symptoms consistent with asthma in rural areas of Navarre were determined for the first time. The number of studies in other rural areas in Spain is small. The percentage of schoolchildren who had had wheezing at any time is significantly higher among children aged 6–7 years (18.3% in boys and 16.2% in girls), than in the 13- to 14-year group (6.7% in boys and 7.3% in girls). The frequency of recent wheezing was 14.1% in primary schoolchildren and 10% in secondary schoolchildren. However, 13.4% of schoolchildren aged 13–14 years had had asthma at some time, compared to 11.7% of children in the 6- to 7-year group. As we can see, the prevalence of asthma is higher among children in rural areas of Navarre compared to other rural areas of Spain, and lower among adolescents.7 Compared to urban regions of Navarre, prevalence is higher in schoolchildren of both age groups.6
AuthorshipI. Elizalde, F. Guillén and I. Aguinaga participated in the conception and design of the study, data collection, and analysis and interpretation of data. They are responsible for the study and guarantee that all integral aspects of the manuscript have been reviewed and discussed among the authors for the intended purposes.
I. Elizalde wrote the article, and F. Guillén and I. Aguinaga participated actively in the critical review of the manuscript and made important intellectual contributions.
F. Guillén and I. Aguinaga approved the final version for publication.
We thank Pablo Roles López, educational psychologist, for his help in administering and collecting the questionnaires in the schools.
We also thank Juan Ramón Elorz, General Director of Education of the Department of Education of the Government of Navarre, for data on the schools provided by the Department of Education of the Government of Navarre.
And finally, we also thank Arkaitz Galbete of the Navarrabiomed-Centro de Investigación Biomédica for statistical advice.
Please cite this article as: Elizalde-Beiras I, Guillén-Grima F, Aguinaga-Ontoso I. Prevalencia de asma en la infancia y adolescencia en una zona geográfica de características rurales. Arch Bronconeumol. 2017;53:460–461.
