Use of lung function tests in asthmatic children is associated with lower risk of hospitalization. A Danish population-based follow-up study.

BACKGROUND

Asthma is the most common chronic disease in childhood. Large variations in hospitalization rates are observed and adherence to and appropriateness of guidelines are often subject of discussion. The aim was to examine if adherence to guidelines concerning use of lung function tests at time of diagnosis and during the first year after the start of medical treatment was associated with risk of hospitalization.

RESEARCH DESIGN

A Danish nationwide population-based cohort study was performed for the study period 1999-2004 using data from five nationwide registries linked by a unique personal registration number.

METHODS

Risk of hospitalization was examined in relation to whether asthmatic children aged 6-14 had a lung function test at the start of treatment and during the first year of follow-up and a medication ratio of controller-to-total medication of at least 0.5. Cox regression analysis was used to calculate hazard ratios (HRs) adjusted for sex, age, socioeconomic factors, care provider, and severity of disease.

RESULTS

A total of 27,193 asthmatic children were followed for at least 1 year after the start of medication. The adjusted HR for hospitalization was 0.64 (95% confidence interval: 0.55-0.74) for having had a lung function test at the start of treatment; 0.82 (0.68-1.00) for having had a lung function test during the first 6 months of follow-up; 0.67 (0.55-0.81) for having a medication ratio of at least 0.5. Children from low-income families and children aged 6-8 had an increased risk of hospitalization.

CONCLUSION

Adherence to the guidelines concerning use of lung function test for asthmatic children was associated with a reduced risk of hospitalization. Likewise, a medication ratio of controller-to-total medication of at least 0.5 was associated with a lower risk of hospitalization.