摘要：Objectives. We compared a statewide telephone health survey with electronic health record (EHR) data from a large Wisconsin health system to estimate asthma prevalence in Wisconsin. Methods. We developed frequency tables and logistic regression models using Wisconsin Behavioral Risk Factor Surveillance System and University of Wisconsin primary care clinic data. We compared adjusted odds ratios (AORs) from each model. Results. Between 2007 and 2009, the EHR database contained 376 000 patients (30 000 with asthma), and 23 000 (1850 with asthma) responded to the Behavioral Risk Factor Surveillance System telephone survey. AORs for asthma were similar in magnitude and direction for the majority of covariates, including gender, age, and race/ethnicity, between survey and EHR models. The EHR data had greater statistical power to detect associations than did survey data, especially in pediatric and ethnic populations, because of larger sample sizes. Conclusions. EHRs can be used to estimate asthma prevalence in Wisconsin adults and children. EHR data may improve public health chronic disease surveillance using high-quality data at the local level to better identify areas of disparity and risk factors and guide education and health care interventions. Asthma is a complex chronic disease with intermittent symptoms and varying degrees of severity. This often makes it difficult to determine its prevalence in a population. Nationally, asthma is estimated to affect approximately 10% of children aged 17 years and younger and 8% of adults, 1 and is associated with significant morbidity and substantial health care costs. The economic cost of asthma in the United States was estimated at $59.0 billion in 2007, including direct health care costs of $53.1 billion and indirect, or lost productivity, costs of $5.9 billion. 2 These outcomes are largely preventable with targeted interventions. 3 Ideally, asthma surveillance should identify disproportionately affected populations and guide prevention and intervention efforts. Surveillance data for chronic diseases are traditionally drawn from federally supported health surveys that provide estimates of asthma prevalence at the national and state levels but not at the local level, where many policy decisions are made. The Behavioral Risk Factor Surveillance System (BRFSS) is the only source of data on health-related behaviors and outcomes for many states, and it is the principal source of asthma prevalence data for Wisconsin. 4 The Wisconsin telephone-based BRFSS survey contains self-reported disease and risk factor data for approximately 4500 adults and 1100 children annually. The BRFSS sample depends on available federal funding and may vary widely from year to year. Although data are provided at the county level, the sample size is often too small for direct estimation of disease prevalence at this geographical level. Electronic health records (EHRs) are increasingly used in research to identify patients with chronic diseases for surveillance and epidemiological studies. 5–7 We compared asthma prevalence estimates in the Wisconsin child and adult population from the traditional statewide BRFSS telephone survey and EHRs from a large Wisconsin health system. We hypothesized that a reliable estimate of asthma prevalence can be made from EHR data at a local level when compared with telephone survey data.
