Emergency department utilization following the introduction of a new primary health care center in Wiener Neustadt, Austria: an interrupted time series analysis.

BACKGROUND: Emergency department (ED) overcrowding is an important public health issue, one cause of which is utilization of care by nonurgent cases that could instead be treated in an outpatient setting. One health policy measure that has been implemented in many healthcare systems is the expansion of primary care to alleviate dependence on EDs. OBJECTIVE: In Austria, primary health care centers (PHCCs) are being expanded to mitigate the increasing ED visits. The opening of a PHCC in Wiener Neustadt served as a quasi-experiment that allowed us to examine changes in ED admissions following the opening. METHODS: An interrupted time series analysis (ITSA) was used to estimate trends before and after the PHCC opened. Administrative data from the hospital emergency department were analyzed. Stratification by age, gender, and Manchester Triage priority was applied to examine differential effects. Influenza adjustment was included to account for seasonal effects. RESULTS: The ITSA revealed an increasing trend prior to the PHCC opening (β1 = 0.01). At the interruption point, a significant level change (β2 = 8.01) was observed that could not be explained by seasonal effects. Overall, after the PHCC opening a reversed trend in ED admissions (β3 = -0.03) was found. Urgent cases were unaffected, whereas nonurgent cases exhibited a significant declining trend. CONCLUSIONS: This study shows that expanding PHCC services is associated with changes in ED utilization trends. Possible associations between PHCC opening and ED visits are found and do not occur immediately.