Calculation of WIES7 (Part A)(Part B)

Calculating WIES7

To calculate the WIES allocated to a patient you need to:-

• Determine if the episode is eligible for WIES funding (see box 1).
• Calculate any WIES co-payment (see box 2a, 2b, 2c)
• Calculate the base WIES allocation using the VIC-DRG3 and the patient’s length of stay adjusted for mechanical ventilation per diem. This can be done using the appropriate weights from the "lookup" table.
• Apply the Aboriginal and Torres Strait Loading if applicable (see box 4).
• Add the base WIES payment, any co-payments and ATSI loading (see box 5).

The steps are described in detail below with technical specifications provided in the boxes.

Box 1: Episodes eligible for WIES funding All episodes are eligible for WIES funding except for: Episodes with the following care types: 1 NHT/Non-acute 2,6,7 Designated Rehabilitation Program/Unit (Levels 1 and 2) 9 Designated Geriatric Evaluation and Management Program 5 Designated Psychiatric Unit or Psychogeriatric Program 3 Family choice: Awake attendant care Episodes where contract role is B. Incomplete or uncoded episodes, or episodes coded to a problem VIC-DRG3 (zero weight) including VIC-DRG3s 951, 952, 955 and 956. Episodes with a program funding source other than Acute Health Services.

1. Scope

The majority of patients in hospitals will be eligible for WIES funding. However, not all patients are eligible for WIES funding because they are in a separately funded program (e.g. as a geriatric management patient in the Aged Care program) or contracted patients. Furthermore, WIES cannot be calculated for incomplete or uncoded episodes.

Eligible patients might be entitled to different types of WIES payments including base WIES payments and WIES co-payments. Base WIES payments are made according to the formula which models the average costs for patients in each VIC-DRG3. WIES co-payments are made to cover the higher costs of care provided to some special types of patients.

Base WIES payments to long stay patients can be affected by co-payments, so it is advisable to determine if a patient is eligible for WIES co-payments first.

2. Co-payments

For 1999-2000 there are three types of co-payments: mechanical ventilation; thalessaemia; and hip revision. Technical specifications for mechanical ventilation co-payments are given in box 2a, technical specifications for thalessaemia co-payments are given in Box 2b and technical specifications for hip revision co-payments are given in box 2c.

To be eligible for a mechanical ventilation co-payment the patient must have had at least six hours of continous mechanical ventilation and have been allocated to a VIC-DRG3 that is eligible for a mechanical ventilation co-payment. VIC-DRG3s are classed as either:

• Eligible for daily co-payments of 0.7729 WIES ("D" in the table);
• Eligible for an episode WIES co-payment 3.1323 when the ICD-10-AM procedure code 13882-02 is present ("E" in the table);
• Eligible for daily co-payments at 0.7729 WIES for ventilated days in excess of four days (96 hours) mechanical ventilation ("4" in the table); or
• Ineligible for co-payments ("I" in the table).

Mechanical ventilation co-payments are only made to patients admitted to specific hospitals (see Related Definitions). 

Base WIES payments for high outliers are reduced when a patient receives daily mechanical ventilation co-payments. To make this reduction you will need to remember the number of days receiving mechanical ventilation co-payments ("adjmvday" in the technical specifications).

Thalessaemia co-payments are made to patients with any ICD-10-AM diagnosis code of D56.x or D57.2 who are allocated to an eligible VIC-DRG3 (indicated with a "Thal." in the "Other Co-payments" column in the table). For 1999-2000 the thalessaemia co-payment is set at 0.2648 WIES per episode. Technical specifications are provided in box 2b. 

The hip revision co-payment of 0.9108 WIES has been introduced for 1999-2000 to compensate hospitals for the higher costs of hip revisions compared to hip replacements and partial hip replacements. Patients are eligible for the co-payment if they are allocated to an eligible hip VIC-DRG3 (indicated with "Redo" in the "Other Co-payments" column) and have an ICD-10-AM procedure code of 49324-00.

Box 2a: Calculating Mechanical Ventilation Co-payments Select mv_elig case "D" then if (hours on mechanical ventilation > 6) and (ICU hospital) then Adjmvday = round((hours mechanical ventilation +12)/24) else adjmvday = 0 mv_copay = adjmvday ´ 0.7729 go to box 2b case "E" then adjmvday = 0 If any procedure of 13882-02 and in NICU hospital mv_copay = 3.1323 else mv_copay = 0 go to box 2b case "4" then if (hours on mechanical ventilation > 96) and (ICU hospital) then adjmvday = round((hours mechanical ventilation +12)/24) - 4 else adjmvday = 0 mv_copay = adjmvday ´ 0.7729 go to box 2b otherwise do adjmvday = 0 mv_copay = 0 go to box 2b

Box 2b: Calculate Thalessaemia Co-payment If ( copay = "Thal.") and record has an ICD-10-AM diagnosis of D56.x or D57.2 then th_copay = 0.2648 else th_copay = 0; go to box 3a

Box 2c: Calculate Hip Revision Co-payment If ( copay = "Redo") and record has an ICD-10-AM procedure of 49324-00 then hip_copay = 0.9108 else hip_copay = 0; go to box 3a

3.Base WIES

To calculate a patient's base WIES you need to determine:

• The patient’s VIC-DRG3.
• The patient’s length of stay.
• The patient’s length of stay category ("S" or same day, "O" or one day, "M" or multiday).
• The number of mechanical ventilation co-payment days ("adjmvday" see box 2a).
• The patient’s inlier status ("I" or inlier, "L" or low outlier, "H" or high outlier).

The patient’s length of stay and length of stay category are derived from the admission date, separation date and leave days. For payment purposes a maximum length of stay of five years (1825 days) is used. This ensures that WIES are not allocated to extreme stays that are likely to represent non-acute care. Technical specifications are given in Box 3a.

The patient’s inlier status is determined by comparing the patient’s length of stay with the inlier boundaries for the VIC-DRG3 to which the patient is allocated. The low inlier and the high inlier boundaries are given in the weights table.

A patient is classified as an inlier when their length of stay is greater than or equal to the low inlier boundary and less than or equal to the sum of the high inlier boundary plus any mechanical ventilation co-payment days.

Patients with a length of stay less than the low inlier boundary are classified as low outliers.

Patients with a length of stay greater than the sum of the high inlier boundary and mechanical ventilation co-payment days are classified as high outliers. Technical specifications are given in box 3b.

Separate columns occur in the weights "lookup" table for episodes which are

• same day
• one day
• multiday low outliers
• multiday inliers
• high outliers.  

The base WIES score for sameday episodes (inlier and low outlier), one day episodes (inlier and low outliers), and multiday inliers can be read directly from the table using the appropriate column and row (VIC-DRG3). The base WIES score for multiday low outliers can be calculated by multiplying the per diem weight given in the table by the patient’s length of stay. The base WIES score for high outliers is obtained by multiplying the number of high outlier days by the high outlier per diem weight (from table) and adding the multiday inlier weight (from table). Technical details are provided in box 3c.

High outlier days are days stayed in excess of the high outlier boundary minus any mechanical co-payment ventilation days ("adjmvdays" - see box 2a).

Inlier Equivalent Separations (IES7) can be calculated by dividing the base WIES by the multiday inlier weight. 

Box 3a: Determining Length of Stay Category and Maximum Length of Stay Sameday='Y' if admission date = separation date Else sameday='N' If (sameday = 'Y') then LOS_cat = "S" go to step 3b else if (sameday = 'N') and (LOS =1) then LOS_cat = "O" go to step 3b else LOS = min(LOS,1825) LOS_cat = "M" go to box 3b

Box 3b: Calculate Inlier Status If LOS < LB then Inlier = "L" go to box 3c else if LOS > (HB + adjmvday) then Inlier = "H" go to box 3c else Inlier = "I" go to box 3c

Box 3c: Calculate Base WIES Select Inlier case "L" do select LOS_cat case "S" do base WIES_x = sd_x IES = base_WIES_x ¸ md_in__x go to box 4 case "O" do base WIES_x = od_x IES = base_WIES_x ¸ md_in__x go to box 4 case "M" do base WIES_x = LOS ´ lo_pd_x IES = base_WIES_x ¸ md_in__x go to box 4 case "I" do IES=1 select LOS_cat case "S" do base WIES_x = sd_x go to box 4 case "O" do base WIES_x = od_x go to box 4 case "M" do base WIES_x = md_in__x go to box 4 case "H" do high_days = max(0, LOS - hb - adjmvday) base WIES_x = Md_in__x + high_days ´ ho_pd_x IES = base_WIES_x ¸ Md_in__x go to box 4

Aboriginal and Torres Strait Islander Loading

In recognition of their poorer health status and the often higher costs of providing their health care, a 10% WIES premium is paid to hospitals for treating Aboriginal and Torres Strait Islanders. Technical details are given in box 4. 

The WIES score is calculated by adding base WIES, co-payment WIES and ATSI WIES. Details are provided in box 5.

 

Box 4: Applying the Aboriginal and Torres Strait Islander Loading If aboriginality in (5,6,7) then do ATSI WIES = 0.1 ´ (base WIES_x + mv_copay + th_copay + hip_copay) else ATSI WIES = 0 go to box 5

Box 5: Calculating WIES Score WIES7_x = base WIES_x + mv_copay + th_copay + hip_copay + ATSI WIES