Abstract
Rationale: Although <5% of children hospitalized with an asthma exacerbation have pneumonia that can be radiographically confirmed, at some hospitals, an asthma-pneumonia co-diagnosis is so common that the term "asthmonia" is used to describe the phenomenon. High rates of asthmonia diagnosis may incur unwarranted health care costs and contribute to unnecessary antibiotic prescribing. Objectives: To characterize hospital variation in rates of pediatric asthmonia diagnosis and analyze associations between hospitals' asthmonia diagnosis rates and clinical outcomes. Methods: We conducted a cross-sectional analysis of 274 hospitals contributing to the Premier Healthcare Database. Children and adolescents 2-17 years of age were included if they were hospitalized with an asthma exacerbation from 10/1/2015 to 6/30/2018. Asthmonia was defined as a discharge diagnosis of pneumonia in a patient with an asthma exacerbation. To compute hospital-level risk-standardized asthmonia rates, hierarchical generalized linear models with hospital random effects were estimated, adjusting for patient characteristics. The median odds ratio was calculated to quantify the effect of hospital-level clustering on asthmonia diagnosis. Hospitals were stratified into quartiles based on risk-standardized asthmonia diagnosis rates to identify associated hospital characteristics. Generalized linear models, adjusting for hospital characteristics, were developed to compute associations between hospital risk-standardized rates and clinical outcomes. Results: Of 24,606 asthma exacerbations, 19,402 (78.9%) were diagnosed with asthma alone and 5,204 (21.1%) received asthma-pneumonia co-diagnoses. The hospital median risk-adjusted asthmonia diagnosis rate was 20.9% (interquartile range, 16.2-27.2%; range, 8.4-55.9%). The median odds ratio was 1.75 (95% confidence interval, 1.63-1.86). Compared with hospitals in the lowest quartile of asthma-pneumonia co-diagnosis, those in the highest quartile were more likely to be smaller, nonteaching, rural hospitals with minimal subspecialty support (all P < 0.001). Hospitals with high rates of risk-standardized asthmonia diagnosis had greater antibiotic use, more prolonged lengths of stay, and higher costs, with no significant differences in risk of transfer or readmission. Conclusions: Marked variation exists in rates of asthmonia diagnosis, and the hospital of admission is one of the strongest predictors of diagnosis. Efforts to reduce rates of unwarranted asthmonia diagnosis are needed, particularly at small, rural, nonteaching hospitals with minimal pediatric specialty support.