Factors associated with self-assessed asthma severity.

Background: Asthma severity can be estimated as the level of medication needed to achieve asthma control or by the patient's subjective assessment. Factors associated with self-assessed asthma severity are still incompletely explored.
Aim: The aim was to study factors associated with self-assessed moderate or severe asthma.
Method: In total, 1828 randomly selected asthma patients from primary (69%) and secondary (31%) care, completed a questionnaire including items about patient characteristics, comorbidity, the Asthma Control Test (ACT), emergency care visits and a scale for self-assessed asthma severity. Logistic regression was used to analyze associations with the dependent variable, self-assessed moderate or severe asthma in the entire study population and stratified by sex.
Results: Of the patients, 883 (45%) reported having moderate or severe asthma. Factors independently associated with self-assessed moderate or severe asthma were age >60 years (OR [95% CI] 1.98 [1.37-2.85]), allergic rhino-conjunctivitis (1.43 [1.05-1.95]), sinusitis (1.45 [1.09-1.93]), poor asthma control as measured by ACT <20 (5.64 [4.45-7.16]) and emergency care visits the previous year (2.52 [1.90-3.34]). Lower level of education was associated with self-assessed moderate/severe asthma in women (1.16 [1.05-2.43]) but not in men (0.90 [0.65-1.25]), p for interaction = .012.
Conclusion: Poor asthma control, allergic rhino-conjunctivitis, recent sinusitis and older age were independently associated with self-assessed moderate or severe asthma. Important implications are that comorbid conditions of the upper airways should always be considered as part of asthma management, and that elderly patients may need extra attention.