ML7: AMA 6 GUIDES

Abstract

The current 6th Edition of the AMA Guides presents a paradigm shift from objective impairment assessment to one of disability rating based not only on functional activity but on participation in a life situation. AMA 6 evaluates disability more strongly than previous editions.

The methodology is to base assessment on diagnosed based impairment (DBI) using DBI grids that have been formulated for each diagnosed condition, each as a class of diagnosis (CDX) eg. rotator cuff injury. These grids are further modified internally by using grade modifiers for:

1. Functional History (GMFH).

2. Physical Examination (GMPE)

3. Clinical Studies (GMCS).

These internal grades allow the assessor to grade each DBI within its class and fine tune the assessment to promote greater reliability. NB. Adjustment factors only allow change within that class. The 6th Edition emphasises the importance of causation in forming the diagnosis and it differs from previous guides in that it allows for impaction on activities of daily living to apply not just to the spine but to the upper and lower limbs. These ADL’s can be normal activities such as swimming and bathing, or Instrumental ADL’S such as meal preparation.

Considerable weight is given to functional assessment and aids the functional history and includes:

1. QuickDash for the upper limb.

2. AAOS Lower Limbs Outcomes Questionnaire.

3. PDQ score (Pain and Disability) applied to the spine.

Pain Rated Impairment (PRI) allows up to a 3% modifier in certain circumstances. Burden of Treatment Compliance (BOTC) allows an additional modifier up to 2 of 3% when it can be reasonable assessed that but for medication, the claimant would have had a higher WPI.

There are special tables for entrapment syndromes, amputation impairment and complex regional pain syndrome (CRPS). Mental and behavioural problems and chronic pain resulting from musculo-skeletal disorders is usually captured within the rating of that disorder itself and, as such, independent mental health impairment rating is considered to be double dipping.

The final figure for impairment is based on the net adjustment formula as set out in the guides. (GMFH−CDX) + (GMPE − CDX) + (GMCS − CDX)

The AMA 6th Edition, relies on diagnosis based impairment, rated on disability, and certain unreliable physical examinations have been excluded, such as the range of motion in the spine, grip strength measurements and using certain operative procedures to delineate assessment rather than the functional outcome of that procedure. A comparison of range of motion bilaterally is now mandatory and sensory deficit is based on two point discrimination when there has been nerve division and monofilament testing when there is decreased light touch. Here nerve conduction studies have assumed particular importance with entrapment syndromes.

AMA 6 guides represents a new approach to impairment assessment based on disability rating which requires greater clinical acumen and cannot be achieved without adequate medical knowledge. ComCare is obliged to use the new guides under current legislation and this is already in use in several jurisdictions around the world.