Use of a risk nomogram to predict emergency department reattendance in older people after discharge: a validation study

In older people, revisit to the emergency department (ED) in the short period after discharge is not entirely avoidable, but in a proportion of cases is preventable, and should ideally be minimised. We have previously derived a risk probability nomogram to predict the likelihood of revisit. In this study, we sought to validate the nomogram for use as a general risk stratification tool for use in older people being discharged from ED. We conducted a prospective cohort study, applying the nomogram to consecutive community dwelling discharged patients aged 65 and over. Patients were followed up at 28 days post-discharge to determine whether there had been any unplanned ED revisit in that period. We cross tabulated predicted risk versus revisit rates. In 1143 study subjects, we find the odds of revisit increases progressively with increasing strata of predicted risk, culminating in an OR of 9.7 (95 % CI 4.7–19.9) in the highest risk group. The 28-day revisit rates across strata range from 16 % through 65 %, with the difference between strata being statistically highly significant ( p < 0.001). The area under the ROC curve is 0.65. We conclude that the risk nomogram can classify older people discharged from ED into risk strata, and has modest overall predictive value.