Most functional assessment scales measure ability to perform a task. These scales do not take the consequences of performing a task into account. Given that the defining feature of ME/CFS is post exertional symptom exacerbation, no functional measure can adequately measure ME/CFS disability without capturing the symptom flares that follow activity.
Luckily, the World Health Organisation Disability Assessment Schedule (WHODAS 2.0) queries the consequences of performing a task (eg. increased pain and incapacity), as well as the difficulty of performing a task (eg. slowness). Therefore, it reflects a respondent’s capacity, as well as ability. For this reason, the WHODAS 2.0 should be used in all occupational therapy (OT) reports for adults with ME/CFS, especially for the NDIS. Here is a list of NDIS-approved assessment tools (look under ‘Primary Disability – Other’ – https://www.ndis.gov.au/applying-access-ndis/how-apply/information-support-your-request/types-disability-evidence and https://www.ndis.gov.au/print/pdf/node/1030.
The WHODAS 2.0 can be used with adults. For children, consider using the Vineland Adaptive Behaviour Scale.
There are two ways to score the WHODAS 2.0.
- Simply add the scores together. This is simple scoring. Simple scores might be useful in clinical practice. However, they cannot be compared with other peoples’ scores. Simple scores should not be included in reports.
- Complex scoring uses item response theory (IRT). Complex scoring assigns different weights to each response. Complex scores are normed against large, worldwide populations. Therefore, a complex score can be assigned a disability percentile. Occupational therapists writing a functional assessment for a person with ME/CFS should always use complex scoring.