Table 1.

Calculations to estimate cost ^{^}

Patient DRG	Data source	Fractured neck of femur, +c/c
Fixed costs (estimated)	State data	$670
Variable costs (estimated)	State data	$6,570
Average length of stay for the DRG	State data	8 days
Daily variable cost	State data	$6,570/8 = $820
Actual length of stay	Study data	11 days
Actual estimated cost	Study data * State data	11 * $820 + $670 = $9690
If patient length of stay is above the average for the DRG:
Extra length of stay	Study data – State data	11 - 8 = 3 days
Extra cost	Study data * State data	3 * $820 = $2460

^{^}Example uses Fractured Neck of Femur with complication and/or comorbidity (+c/c) (DRG I78A), figures rounded to reflect estimation status.

DRG = Diagnostic Related Group.

State data = all ages overnight NSW public hospital episodes.

Study data = 50+ overnight NSW public hospital episodes.