Objectives: We sought to determine the additional disease burden imparted by sinusitis and hay fever (allergic rhinitis) to patients with asthma.

Methods: Patients with a diagnosis of asthma, hay fever, or sinusitis were extracted from the National Health Interview Survey for the 1997 to 2006 adult sample. Disease groups consisting of patients with asthma alone, asthma + hay fever, asthma + sinusitis, and asthma + hay fever + sinusitis were assembled. Disease groups were then compared according to total health-care visits per year, emergency room visits per year, health-care spending per year, and number of workdays lost per year to determine the disease burden.

Results: We identified 11,813 patients (mean age, 45.5 years) who reported active asthma with or without hay fever or sinusitis comorbidity. Of these, 5,931 patients (50%) were identified with asthma alone, 1,134 (10%) with combined asthma + hay fever, 2,461 (21%) with asthma + sinusitis, and 2,287 (19%) with combined asthma + hay fever + sinusitis. Patients with asthma + sinusitis and those with asthma + sinusitis + hay fever had more total health-care visits and emergency room visits than did those with asthma alone (p <0.001). All three groups with comorbidities had higher healthcare expenditures than did the group with asthma alone (p < or = 0.002). Patients with asthma + sinusitis and those with asthma + hay fever + sinusitis missed more workdays than did patients in the group with asthma alone (10.0 and 13.1 versus 7.2, respectively; p <0.001). Comorbid hay fever alone did not increase workdays lost (6.6 days; p = 0.983).

Conclusions: The additional disease burden of sinusitis on asthma is greater than that of hay fever. These data highlight the importance of identifying comorbid diagnoses with asthma.