The impact of psychiatric illnesses upon asthma patients' functioning is not well understood. This study examined the impact of psychiatric comorbidity upon illness management in asthma patients using empirically-derived psychiatric comorbidity groups. Participants were a clinic sample of Greek-speaking asthma patients (N = 212) assessed using the Patient Health Questionnaire (PHQ) Somatoform, Depression, Panic Disorder (PD), Other Anxiety Disorder, Eating Disorder (ED) and Alcohol sub-scales. The associations between sub-scales were examined using multiway frequency analysis. The following groups were derived: Somatoform disorder and/or Any Depressive disorder (n = 63), Somatoform disorder and/or Other Anxiety disorder (n = 51), Somatoform disorder and/or Any ED (n = 60), and Any Anxiety group including PD and/or Other Anxiety disorder (n = 24). Across all groups, psychiatric illness was associated with significantly worse asthma control (p < .01). Participants in Any Anxiety group, OR = 4.61, 95% CI [1.90, 11.15], Somatoform and/or Any Depressive disorder, OR = 2.06, 95% CI [1.04, 4.09] and Somatoform and/or Other Anxiety disorder, OR = 2.75, 95% CI [1.35, 5.60] were at higher risk for asthma-related Emergency Room (ER) visits compared to controls. However only Somatoform and/or Any Depressive disorder, OR = 3.67, 95% CI [1.60, 8.72], Somatoform and/or Other Anxiety disorder, OR = 5.50, 95% CI [2.34, 12.74], and Somatoform and/or Any ED, OR = 4.98, 95% CI [2.14, 11.60] group membership were risk factors for asthma-related hospitalizations. Results suggest that while comorbid psychiatric disorders generally negatively impact asthma illness management, different psychiatric comorbidities appear to have disparate effects upon illness management outcomes.
Keywords: Psychiatric comorbidity; asthma; healthcare utilization; illness management.