“…The neural network methodology has particular application to determining the value of case mix (chief complaint) data in that it can be used to perform classification of this variable without knowledge of the underlying probability model and can automatically include nonlinear and combination (interaction) terms [12,13]. Our objective was to apply the neural network methodology to determine whether adding coded chief complaint (CCC) data, a previously studied marker of ED patient case mix [14], to demographic, operational, and acuity data available at triage would result in an improved hospital admission prediction model than one using demographic, operational, and acuity data alone.…”