Lower respiratory tract infections appear to be the most important risk factor for current asthma in subarctic schoolchildren.

Aim: The aim of this study was to identify possible risk factors for current asthma revealed by two studies in Northern Norway in 1985 and 2008 and to evaluate these factors contributing to the increased prevalence of asthma over these 23 years.

Methods: As part of the 'Asthma and allergy study among schoolchildren in Nordland county' we performed a case-control study (70.0% attendance) comparing 153 children with current asthma (cases) to their non-asthmatic controls.

Is inter-rater reliability of Global Trigger Tool results altered when members of the review team are replaced?

Objective: To evaluate the inter-rater reliability of results from Global Trigger Tool (GTT) reviews when one of the three reviewers remains consistent, while one or two reviewers rotate.

Design: Comparison of results from retrospective record review performed as a cross-sectional study with three review teams each consisting of two non-physicians and one physician; Team I (three consistent reviewers), Team II (one of the two non-physician reviewers or/and the physician from Team I are replaced for different review periods) and Team III (three consistent reviewers different from reviewers in Team I and Team II).

Setting: Medium-sized hospital trust in Northern Norway.

Validation of a questionnaire against clinical assessment in the diagnosis of asthma in school children.

Aim: A questionnaire has been used repeatedly in cross-sectional studies to determine the prevalence of asthma, allergic rhinoconjunctivitis (AR) and eczema among schoolchildren in Nordland County, Norway. The current study was designed to validate the questionnaire against clinical assessment as the diagnostic gold standard and to investigate the extent of possible misclassification.

Methods: A subsample of 801 schoolchildren of 4150, whose parents had answered a questionnaire covering asthma and atopic diseases, underwent a detailed clinical evaluation including a standardized interview, a clinical examination, skin prick tests (SPT), blood samples, spirometry an exercise treadmill test (EIB test) and measurement of exhaled nitrogen oxide (FeNO).

Increasing prevalence of asthma, allergic rhinoconjunctivitis and eczema among schoolchildren: three surveys during the period 1985-2008.

Aim: The prevalence of asthma, allergic rhinoconjunctivitis (AR) and eczema among children has increased worldwide in the last four decades, but recent studies disagree as to whether the prevalence is continuing to rise or is levelling off or declining. The aim of this study was to assess time trends in a subarctic population.

Methods: A cross-sectional, questionnaire-based survey was carried out in 2008 among children aged 7-14 years in randomly selected schools in Nordland County, Norway (n = 4150).