Expanding Health Information Exchange Improves Identification of Frequent Emergency Department Users.

STUDY OBJECTIVE: Frequent emergency department (ED) users are of interest to policymakers and hospitals. The objective of this study is to examine the effect of health information exchange size on the identification of frequent ED users. METHODS: We retrospectively analyzed data from Healthix, a health information exchange in New York that previously included 10 hospitals and then grew to 31 hospitals. We divided patients into 3 cohorts: high-frequency ED users with 4 or more visits in any 30-day period, medium-frequency ED users with 4 or more visits in any year, and infrequent ED users with fewer than 4 visits in any year. For both the smaller (10-hospital) and larger (31-hospital) health information exchanges, we compared the identification rate of frequent ED users that was based on hospital-specific data with the corresponding rates that were based on health information exchange data. RESULTS: The smaller health information exchange (n=1,696,279 unique ED patients) identified 11.4% more high-frequency users (33,467 versus 30,057) and 9.5% more medium-frequency users (109,497 versus 100,014) than the hospital-specific data. The larger health information exchange (n=3,684,999) identified 19.6% more high-frequency patients (52,727 versus 44,079) and 18.2% more medium-frequency patients (222,574 versus 192,541) than the hospital-specific data. Expanding from the smaller health information exchange to the larger one, we found an absolute increase of 8.2% and 8.7% identified high- and medium-frequency users, respectively. CONCLUSION: Increasing health information exchange size more accurately reflects how patients access EDs and ultimately improves not only the total number of identified frequent ED users but also their identification rate.

High-frequency users of emergency department care.

BACKGROUND: The heterogeneous group of patients who frequently use the Emergency Department (ED) have been of interest in public health care reform debate, but little is known about the subgroup of the highest frequency users. STUDY OBJECTIVES: We sought to describe the demographic and utilization characteristics of patients who visit the ED 20 or more times per year. METHODS: We retrospectively studied patients who visited a large, urban ED over a 1-year period, identifying all patients using the department 20 or more times. Age, gender, insurance, psychosocial factors, chief complaint, and visit disposition were described for all visits. Inferential tests assessed associations between demographic variables, insurance status, and admission rates. RESULTS: Of the 59,172 unique patients to visit the ED between December 1, 2009 and November 30, 2010, 31 patients were identified as high-frequency ED users, contributing 1.1% of all visits. Patients were more likely to be 30-59 years of age (52%), stably insured (81%), and have at least one significant psychosocial cofactor (65%). Their admission rate was 15%, as compared to 21% for all other patients. CONCLUSIONS: High-frequency users are patients with significant psychiatric and social comorbidities. Given their small proportion of visits, lower admission rates, and favorable insurance status, the impact of high-frequency users of the ED may be out of proportion to common perceptions.