Rationale: Despite the importance of trigger perceptions for asthma diagnosis and management, associations among asthma triggers, affective disorders, and asthma outcome have received little attention.
Objectives: Because anxiety and depression are known to influence patients' health reports, we measured and controlled for these affective disorders in analyzing associations among patient perceptions of asthma triggers and asthma treatment outcomes.
Methods: Patients from a nationally representative sample of respiratory specialist practices (N = 459) were assessed for clinically significant anxiety and depression and completed questionnaires on asthma triggers, quality of life, and asthma control. Physicians recorded exacerbation and emergency treatment frequencies in the prior year, spirometric lung function, and allergy test results. Hierarchical multiple regressions examined associations among reported trigger factors, anxiety, depression, and asthma outcomes, including quality of life, asthma control, exacerbations, emergencies, and spirometry.
Measurements and main results: Patients across asthma severity levels were well represented. Anxiety and depression were associated with more frequent nonallergic, in particular psychological, triggers. Controlling for demographics, asthma severity, anxiety, and depression, nonallergic asthma triggers (including psychological triggers) explained substantial portions of variance in asthma control (total of 19.5%, odds ratios [ORs] = 2.07-1.37 for individual triggers), asthma-related quality of life (total of 27.5%, ORs = 3.21-1.49), and general quality of life (total of 11.3%, ORs = 1.93-1.55). Psychological triggers were consistently associated with exacerbations and emergency treatments (ORs = 1.96-2.04) over and above other triggers and affective disorders. Spirometric lung function was largely unrelated to perceived asthma triggers.
Conclusions: Patients' perceptions of asthma triggers are important determinants of asthma outcomes, which can help identify individuals at risk for suboptimal asthma management.
Keywords: anxiety; asthma; depression; perceived asthma triggers; quality of life.