In the state of California, disability is based on impairment. Impairment is established by a physician and a disability evaluator based on the physical attributes found in the individual. It is then up to the judge or rater to translate that impairment into disability based on how that impairment affects the ability to work.
In order to determine impairment, it is necessary to use objective criteria. In the state of California, criteria are based on the American Medical Association (AMA) rate impairment guides. The AMA guides determine the criteria on the ability to perform activities of daily living (ADL).
Unfortunately, the ADLs hardly reflect a wide spectrum of jobs and tasks that are necessary to make a fair evaluation of disability. For example, a construction worker with an injury may not be able to perform his/her arduous job but may have no difficulty in performing ADLs. According to the AMA guides, this individual would have no impairment.
A more accurate way to determine impairment is the Cardiopulmonary Exercise Test (CPET). With this test, the maximum oxygen consumption is determined and a third of it is presumed to be what a person could comfortably perform during a standard eight hour shift.
The score or rating a person receives of what he/she could comfortably perform is then compared to oxygen consumption tables that list consumption needs for specific jobs. This results in an extremely accurate determination of jobs that can be performed, thereby also assessing existing disability. Moreover, it is also possible to determine how much physical functioning has been lost due to the injury (otherwise known as the “percentage of pre-injury capacity”). In sum, the data is so reliable there is little room for speculation or estimation as is often done by evaluators.
CPET results are difficult to fake. Anyone who has not reached the anaerobic threshold, and has a large heart rate or breathing reserve cannot claim he/she has reached maximum oxygen consumption (unless other medical conditions are discovered during the test). Since the CPET is performed on a bicycle and with rapid incremental resistance, it is a short test that can be safely done on people with back, arms or even knee injuries.
THE CPET IS CONSIDERED BY MANY TO BE THE GOLD STANDARD OF DETERMINING DISABILITY!