Alergológica 2005. Methodological aspects and sample characteristics of the study.

BACKGROUND In this article we present the basic methodological aspects of the clinical epidemiologic study Alergológica-2005, a project launched by the Spanish Society of Allergology and Clinical Immunology replicating the objectives and methods of a similar study carried out in 1992. OBJECTIVE The aim of this nation-wide study was to describe the profile of the patients treated in Spanish allergology departments, the normal clinical practice followed by the specialists in these departments, the social and healthcare repercussions of allergic diseases in Spain together with the additional objective of identifying any possible relevant changes that may have taken place regarding these factors during the decade since the original study was completed (1992-2005). METHODS An observational, descriptive, cross-sectional study was carried out over the year 2005 using a convenience sample of allergic patients (recruited consecutively from a different random date for each researcher participating in the study) who were treated in the departments, both private and public, of 340 specialists in allergology working in the Spanish healthcare system. The sample was stratified geographically by autonomous region in a ratio proportional to the population of each geographical area. RESULTS Clinical, epidemiological, diagnostic, therapeutic, social and general healthcare data were collected from 4991 allergic patients presenting for the first time in the departments of the researchers involved in the study. The results and conclusions will be presented classified by disorder in the following research articles published in this issue. CONCLUSIONS The methodological aspects described guarantee the accuracy of the estimates made in the current study and the comparability of the results with those of Alergológica-92 project.