Psychiatric comorbidity in asthma patients. Associated factors

To study the prevalence of anxiety and depression in patients with asthma and to identify associated factors.

The study was based on individual data of subjects aged ≥18 years drawn from the 2006 Spanish National Health Survey. We identified asthmatic individuals through a specific questionnaire. Presence of depression or anxiety was assessed using the following questions: ( 1 ) "Have you suffered depression or anxiety over the previous 12 months?" ( 2 ) "Has your medical doctor confirmed the diagnosis?" ( 3 ) "Have you consumed antidepressants prescribed by your physician over the last 2 weeks?" ( 4 ) "Have you consumed anxiolytics prescribed by your physician over the last 2 weeks?" Those who answered yes to questions 1, 2, and 3 or to all questions were considered "Depression sufferers," those who answered yes to questions 1, 2, and 4 were considered "Anxiety sufferers." We analyzed sociodemographic characteristics and health-related variables.

Of the 28,966 subjects included in the study, 1650 were classified as asthmatic (5.6%). The prevalence of anxiety was 9.7% among people with asthma and 6.6% among those without the disease (p < .01). After multivariate adjustment the probability of a subject suffering anxiety was 1.27 (95% CI 1.08-1.49) higher among those with asthma than among those without. Independent and significantly associated variables with anxiety among asthmatic patients were older age, concomitant comorbidities, and visits to general practitioner in the last 4 weeks. The prevalence of depression was 9% among asthmatics and 5.5% among those without the disease (p < .05). The multivariate adjustment revealed that suffering depression was associated with suffering asthma (adjusted OR 1.39, 95% CI 1.18-1.64). Variables associated with depression among asthmatic patients were female sex, older age, worse self-related health, concomitant comorbidities, abstemious individuals, and the need for attendance on emergency room in the last year.

Suffering anxiety or depression is associated with suffering asthma. Associated variables with anxiety or depression among asthmatic patients include older age and concomitant comorbidities.