Emergency department crowding is associated with decreased quality of care for children with acute asthma

Objective: We sought to determine which of several dimensions of quality of care are most affected by emergency department crowding in patients with acute asthma exacerbations. Methods: We performed a cross-sectional study with retrospective data collection from an electronic medical record, including patients 2-21 years seen for acute asthma from November 1, 2007, to October 31, 2008, at a single, children's hospital emergency department. The main outcome measures were 14 quality metrics mapped to five of the six Institute of Medicine dimensions of quality, although only nine measures for three dimensions--timeliness, effectiveness, and equity-- had sufficient numbers for modeling. Three previously-validated crowding measures were assigned to each patient at arrival time. All models were adjusted for age, preferred language, insurance, presence of a primary care provider, triage level, ambulance arrival, pulse-oximetry value, passive smoke exposure, and time of day. For timeliness and effectiveness quality measures, which involved three processes of care, we calculated the adjusted risk of each of the quality measures at five percentiles of crowding for each of the crowding measures, and assessed the significance of the change in adjusted risk when moving between crowding percentiles. For equity measures, we tested their association with effectiveness and timeliness measures, and tested whether they were moderators of the crowding-quality models. Results: The asthma population included 927 patients. Timeliness and effectiveness quality measures all showed a dose-related effect between crowding and quality, significant in 14 of 15 models. Patients were 1.75 (95%CI (confidence interval) (1.47, 2.22)) to 8.33 (95%CI (4.17, 16.67)) times as likely to receive timely care when each crowding measure was at the 10th than at the 90th percentile. They were 1.05 (95%CI (0.99, 1.11)) to 1.19 (95%CI (1.10, 1.28)) times as likely to receive effective care at the 10th than at the 90th percentile. Equity measures had no association with effectiveness and timeliness measures, and did not act as moderators of the crowding-quality models. Conclusion: ED crowding is associated with decreased effectiveness and timeliness of care for children with acute asthma, but not with diminished equity of care.