A recent JAMA publication lead-authored by Dr. Amber Sabbatini examined the scientific soundness of emergency department (ED) return visits as a measure of the ED’s quality of care. Emergency department return visits have been considered for wider adoption as a quality metric, especially for those patients who are hospitalized during the return ED visit. The “quality” that this metric is intended to measure is the quality of ED care delivered, including the safety of the ED physician’s decision to discharge the patient. Patients returning to the ED within 7, 14 and 30 days of the initial visit thus are thought to reflect lower quality of care, particularly if readmitted, as this reflects progression of the patient’s illness to a more severe state after they were mistakenly sent home.
The authors compared in-hospital clinical and utilization outcomes (deaths, need for intensive care unit (ICU) care, length of stay and cost) between two groups of patients: those who were admitted during their initial ED visit, and those who returned to the ED and were hospitalized. They found that
patients who experienced an ED return visit that was associated with admission shortly after ED discharge had significantly lower rates of in-hospital mortality, ICU admission, and costs, but higher lengths of stay compared with admissions among patients without a return visit to the ED.
Patients who are initially sent home from the ED and then return and are readmitted are actually less sick than those admitted to the hospital initially. In aggregate, they are not experiencing increasing severity of illness after discharge from the initial ED visit–in fact, they are less sick than those admitted initially. In some ED’s, this effect may reflect dilution, in that a revisit alone is reason to admit patients regardless of how sick they are medically. A tongue-in-cheek ED adage states that if the pizza boy returns to the ED to deliver another pizza, you admit him.
Putting these findings in context of Donabedian’s structure-process-outcome framework for measuring health care quality, ED revisits are being used to measure ED quality of care. ED quality of care is a process measure as it is a health care-related activity performed for or by a patient, but quality is unmeasured here because it is so hard to measure directly for all diagnoses together. Current ED measures of care quality include throughput metrics–ED length of stay and time from disposition decision to admission–as well as have condition-specific metrics such as time to fibrinolytic treatment for ED patients with acute myocardial infarction.
In Donabedian’s framework, outcomes measure the health state of the patient resulting from health care. Revisits to the ED are not a health state; they are used as a proxy for the outcome of “worsened health status”. By looking at the clinical course of those readmitted during a readmission post discharge from the ED, the authors show that ED revisits are not a good proxy for post-ED-discharge health status.
Thus, ED revisits do not have good construct validity as a proxy for ED quality of care–they do not measure what they purport to measure. One important contributor to this poor validity is that patient-level factors beyond the control of the hospital are significant risk factors for revisits. Social determinants—the circumstances in which people live and work—powerfully affect health; they are estimated to have twice the impact of the quality of an individual’s health care on that individual’s overall health.
The concerns about construct validity and the impact of social determinants of health are similar to those I’ve discussed elsewhere related to hospital readmissions, and related to healthcare performance metrics more broadly.