Choosing wisely in the ED: The diagnostic cascade of needless medical testing in a two-level study.

Background: The diagnostic cascade in the emergency department (ED) has not been fully elucidated. Aim To inspect whether the usage of consulting medicine and imaging contributes to hospital outcomes. We also propose a theoretical model for better understanding the diagnostic cascade of needless medical testing.

Methods: A two-level study was conducted. The first local phase was a retrospective archive study that was conducted between 2014 and 2017 in a tertiary hospital. We extracted the number of requested imaging and consultations for each patient, and main time lags were calculated. The second-phase (January-April 2018) was conducted on a national level. We examined 22 hospitals with the emphasis on five hospital outcomes: recurrent ED visits (within 24 h), median waiting time at the ED, rate of early discharge at the same day and day after and percentage of patients spending >4 h in the ED.

Results: A 5% upsurge in CT scans was observed (p = .032), and a significant increase was found in the number of consultations (14%, p = .002). On a national level, a linear regression model found that the proportion of patients discharged from the hospital on the same day and on the day after and the proportion of patients staying in the ED > 4 h predict ED recurrence visits within 24 h (p = .025; R = 46.3%).

Conclusions: Upsurge in resource usage in the ED leads to a diagnostic cascade of health consumption. Further study is necessary to examine the proposed model in a global scale.