Inpatient adult rehabilitation and the AN-SNAP classification

Owned by Lewis Green
Last updated: 21-09-2022

What is AN-SNAP?

The Australian National Sub-Acute and Non-Acute Patient Classification (AN-SNAP) is a case-mix classification for sub-acute and non-acute care provided in four subacute care types (rehabilitation, palliative care, geriatric evaluation and management and psychogeriatric care) and one non-acute care type (maintenance care).

The first version of the classification was developed in 1997 by the Centre for Health Service Development, University of Wollongong. The current version is the first to be developed by the Independent Health and Aged Care Pricing Authority (IHACPA) (formerly IHPA) and was implemented in July 2022.

The AN-SNAP classification is used by IHACPA for Activity Based Funding (ABF) of Australian subacute hospitals and within rehabilitation it is used for clinical management and benchmarking. The AROC financial year 2022 benchmark reports were the first to use the AN-SNAP Version 5 Classification for benchmarking.

Inpatient rehabilitation AN-SNAP classes

The inpatient (admitted overnight adult) rehabilitation classes use impairment code, age on admission, weighted FIM motor admission score and FIM cognition admission score to determine which of the 48 classes the episode should be assigned to. The full list of inpatient adult rehabilitation version 5 classes can be found here.

What are impairment specific weighted FIM scores?

AN-SNAP Versions 4 and 5 use impairment-specific weighted FIM motor scores in the inpatient (admitted overnight adult) rehabilitation classes. In both versions weights reflect the relative impact of each item on the cost of caring for the rehabilitation patient. If an item has a weight of more than 1, it will have an impact on the cost of care that is more than average – a weight less than 1 implies the impact will be less than average. Within each impairment type, the weights are scaled to sum to 13 – thus both weighted and unweighted scores range from a minimum of 13 to a maximum of 91. Where impairments are grouped together in the classification, a single set of weights for that group has been derived. The FIM motor item stairs in version 5 has all weights set to one.

What changed between V4 and V5?

Between AN-SNAP V4 and V5 there were some minor refinements to the positioning of age and FIM score splits, and minor revisions to the impairment-specific weights used for the FIM item scores in the calculation of a motor score. More significant changes include:

  • The return of orthopaedic replacement classes (lost in Version 4) – 3 classes.
  • Switching of the branching order for the brain injury classes, now split first on cognition FIM scores and split second on motor FIM scores – also the number of brain classes were reduced from 7 to 6.
  • In the lower FIM motor score classes (<19) burns were moved from 5AZ3 and 5AZ4 to 5AZ1 and 5AZ2.
  • The number of classes were increased for stroke (7 to 8) and major multiple trauma (1 to 2).
  • The number of classes were decreased for Amputee (4 to 1), Cardiac, pain syndromes, and pulmonary (4 to 3) and reconditioning (6 to 5).

More information