Incidence of asthma in young adults from Castellon, Spain: A prospective cohort study

BACKGROUND

The objective was to estimate the incidence of asthma in young adults from 13-15 years old to 23-25 years old, and associated factors.

METHODS

In 2012, a population-based prospective cohort study was carried out in Castellon from the cohort who had participated in the International Study of Asthma and Allergy in Childhood in 1994 and 2002. A telephone survey was undertaken using the same questionnaires. A new case of asthma was defined as a participant free of the disease in 2002 who suffered asthma, was diagnosed with asthma, or took medications against asthma based on self-report from 2002 to 2012.

RESULTS

The mean age of participants was 24.9±0.6 with a follow-up of 79.1%. Asthma cumulative incidence was 3.4%: 44 new cases occurred among 1280 participants. The incidence was higher in females than males with relative risk (RR)=2.02 (95% confidence interval [CI] 1.1-3.8). A significant decrease of asthma incidence density was observed (8.2 cases to 3.5 cases per 1000 person/year). Factors associated with the incidence of asthma were allergic rhinitis (RR=4.05; 95% CI 1.7-9.6), bronchitis (RR=2.13; 95% CI 1.0-4.5), mother's age at time of birth (RR=0.87; 95% CI 0.8-0.9) and a pet other than a dog or cat (RR=0.42; 95% CI 0.2-0.9). For gender, some variations in the risk factors were observed.

CONCLUSIONS

A significant decrease in the incidence of asthma was observed. Several risk and protective factors were found.

[Incidence of allergic rhinitis in a cohort of schoolchildren between 1994 and 2002 in Castellón (Spain), following the ISAAC study]

OBJECTIVE

To estimate the incidence of allergic rhinitis in schoolchildren in Castellón by comparing phases I and III of the International Study of Asthma and Allergies in Childhood (ISAAC), carried out in 1994 and 2002, respectively.

MATERIAL AND METHODS

A cohort study was performed with 3607 schoolchildren aged 6-7 years old who participated in phase I of the ISAAC study. Of these, 1805 participated in phase III (8 years later) at the age of 14-15 years, with 1627 schoolchildren without allergic rhinitis in phase I. The cumulative incidence of allergic rhinitis was estimated. Two definitions of new cases of allergic rhinitis were used: the first was based on medical diagnosis or treatment of the disease, and the second also included symptoms of allergic rhinitis in the previous 12 months. Relative risks were calculated using Poisson regression.

RESULTS

Participation was 50.0 %, and 151 new cases of allergic rhinitis according to the first definition (cumulative incidence of 9.3 % and 1.2 % per year) and 339 new cases according to the second definition (cumulative incidence of 20.8 % and 2.6 % per year) were found. No differences in incidence by gender were observed with the first definition (RR = 1.00 95 % CI 0.73-1.38) but with the second definition, the incidence was greater in girls (RR = 1.46 95 % CI 1.18-1.82).

CONCLUSIONS

The cumulative incidence of allergic rhinitis according to the first definition was in the range of incidence from cohort studies of adolescents.

Incidence of allergic rhinitis in a cohort of young adults from 13-15 years old to 23-25 years old in Castellon (Spain)

BACKGROUND

The objective of this study was to estimate the incidence of Allergic Rhinitis (AR) in young adults and its risk or protective factors.

METHODS

A population-based prospective cohort study was carried out in 2012. The cohort participated in the International Study of Asthma and Allergy in Childhood in Castellon in 1994 and 2002. A telephone survey was conducted using the same questionnaires. A new case of AR was defined as the participants free of the disease in 2002, who self-reported suffering from AR or taking medications for AR in the period 2002-2012.

RESULTS

Of the 1805 schoolchildren in the cohort in 2002, 1435 young adults (23-25 years old) participated (follow-up 79.1%) in 2012; 743 were female and 692 male; their mean age was 24.9±0.6 years. Two hundred new cases of AR occurred in 1259 participants free of the disease with an incidence of 17.3 per 1000 person-years, and the incidence increased from 2002 (RR=1.42; 95% CI 1.15-1.75). The risk factors of AR adjusted by age and gender were sinusitis (RR=1.77; 95% CI 1.16-2.68), atopic dermatitis (RR=1.51; 95% CI 1.11-2.06) and constant exposure to truck traffic (RR=1.88; 95% CI 1.12-3.17). For male participants, the risk factors were asthma, sinusitis and atopic dermatitis, and for females bronchitis was a risk factor and presence of older siblings a protective factor.

CONCLUSIONS

An increase in AR incidence was observed. Sinusitis, atopic dermatitis and constant exposure to truck traffic were the risk factors of the AR with some differences by gender.