Gatekeeping Under Congestion:
An Empirical Study of Referral Errors in the Emergency Department
Major revision at Management Science.
Michael Freeman, INSEAD
Susan Robinson, Cambridge University Hospitals
Stefan Scholtes, Cambridge Judge Business School
Using data from over 300,000 visits to an emergency department (ED), we study the effect of congestion on the accuracy of gatekeeping decisions (admission to the hospital or discharge home) and the effectiveness of a second gatekeeping stage (a clinical decision unit (CDU) in our context) at reducing gatekeeping errors. While the total error rate increases with congestion, ED physicians prevent an increase in the potentially more harmful wrongful discharges by lowering the threshold for hospital admission. This leads to an increase in unnecessary hospitalizations precisely at times when the gatekeeping system should protect the scarce specialist resource from the surge of demand in the ED. We show that the introduction of a second gatekeeping stage, to which ED physicians can pass those patients for whom they are unable to make confident referral decisions, can mitigate this effect. When used as a second gatekeeping stage, we find evidence that the CDU reduces both unnecessary hospitalization and wrongful discharges, by 11.6% and 11.3%, respectively. We also demonstrate that the two-stage gatekeeping system performs better than a single-stage system that pools the capacity of both stages.
gatekeeping; congestion; referral error; health care: hospitals; service operations; econometrics