Abstract
BACKGROUND: Little is known about how patient-level factors and care settings relate to asthma outcomes in real-world settings. OBJECTIVE: We therefore examined the rates and relative contributions of comorbidities and care settings in terms of asthma severity and control among pediatric and adolescent/adult patients in a large national sample. METHODS: We examined deidentified patient data from 28,508 unique encounters documented in the Asthma Specialist Tool to Help Manage Asthma and Improve Quality database, obtaining patient-level factors (demographics, asthma characteristics, comorbidities), care setting (primary care physician [PCP] vs specialist physician [allergist or pulmonologist]), and guideline-defined levels of asthma control/severity. Rates of comorbidities were identified by asthma severity and control and by care setting. We calculated odds ratios for asthma control and severity based on each comorbidity. RESULTS: Baseline demographic data indicated that patients seen by specialists versus PCPs were older, and had more severe and poorly controlled asthma (P < .05). Patients cared for by specialists also had more comorbid conditions, including gastroesophageal reflux disease (GERD; P < .01), rhinosinusitis (P < .01), and obstructive sleep apnea (adolescents/adults only: P < .01). GERD, smoke exposure, depression (adolescents/adults), rhinosinusitis (children), and African American race were associated with uncontrolled asthma. Smoke exposure (children), rhinosinusitis, and African American race were associated with severe disease. CONCLUSIONS: We identified several demographics and comorbidities that are independently associated with the specialist care setting, persistent asthma, and poor asthma control. Awareness of these relationships may be helpful for clinicians caring for patients with asthma.