Asthma in changing environments - chances and challenges of international research collaborations between South America and Europe - study protocol and description of the data acquisition of a case-control-study

Abstract

BackgroundAsthma in children is an emerging public health problem in South America. So far, research in this part of the world is limited. This paper presents the methodology and description of the data acquisition of an asthma case-control study conducted in the Central South of Chile.Methods/DesignA hospital-based case-control study about asthma (188 cases, 294 controls) in children (6-15 years) was carried out in Valdivia, Chile between November 2008 and December 2009. Data on asthma risk factors were collected by computer-assisted personal interview using validated questions from e.g. ISAAC phase II. Data on household dust exposure (endotoxin, allergen analyses), skin prick tests to most common allergens, stool examinations for parasitic infection, and blood samples (total IgE, genetics) were collected. Additionally, 492 randomly chosen blood donors were recruited in order to assess allele frequencies in the population of Valdivia.DiscussionOverall 1,173 participants were contacted. Response was 82% among cases and 65% among controls. Atopic sensitization was high (78% among cases, 47% among controls). Cases had a statistically significantly (p < .0001) increased self-reported 12-month prevalence of symptoms of rhinitis (82% vs. 51%) and wheeze (68% vs. 16%). The study is well placed to address current hypotheses about asthma and its correlates in the South American context. Results of this study might help develop novel, innovative and individualized prevention strategies in countries in transition with respect to the South American context.

Childhood Asthma and Allergies in Urban, Semiurban, and Rural Residential Sectors in Chile

“…Therefore, it has been suggested that people who grow up on a farm are exposed to certain immune modulatory factors that are specific to this lifestyle and protect against allergic diseases [12]. …”

“…The hygiene hypothesis has not been widely studied in Chile [12, 13], yet evidence for the hygiene hypothesis is conflicting in Latin America [14]. The aim of the present study was to evaluate the hygiene hypothesis with regard to the development of asthma and allergies in children living in urban, semiurban, and rural residential sectors in the central south of Chile.…”

Comparisons between protocols and publications of case-control studies: analysis of potential causes of non-reproducibility and recommendations for enhancing the quality of personalization in healthcare

“…The studies conducted by following these selected CCS protocols were further searched and 17 protocols that had not published any corresponding studies were excluded. Finally, 14 protocols and the related 24 published CCSs were included in this current study [21][22][23][24][25][26][27][28][29][30][31][32][33][34]. The flow chart of literature search is shown in Fig.…”