Note that hospitals usually include expenses associated with emergency room visits that immediately result in an inpatient stay with the charges and payments for the inpatient stay. Therefore, to avoid the potential for double counting when imputing missing expenses, separately reported facility expenditures for emergency room visits that were identified in the Medical Provider Component (MPC) as directly linked to an inpatient stay were included as part of the inpatient stay only (see HPCHGTOT and HPFCHT). This strategy to avoid double counting resulted in $0 facility expenditures for these emergency room visits (but there still may be associated separately-billing doctor expenses). However, these $0 emergency room visits are still counted as separate visits in the utilization variable ERTOTVIS.