One factor which could potentially limit the reliability of results of this methodology may be represented by the objective difficulty in the choice or definition of reference standards, in particular when they are not available in literature or law, or from institutional objectives or Benchmarking investigations.
In addition, the definition of reference intervals for TPOAbs has limitations due to the natural history of AITD, because a large number of individuals may have specific autoantibodies in serum 10 15 years before the onset of these diseases.
In the Physical/Structural subscale, the definition of reference group was participants who perceived no Physical/Structural environmental barriers (physical and structural barriers score = 0).
To determine the most affected brain regions and for a reproducible definition of reference tissue in MS patients, a database of 6 healthy controls (HC, 3 female and 3 male; mean age 23 ± 6 years; 1 MAB and 5 HAB) was provided by GE Healthcare (The Grove Centre Amersham, UK).
In the subscale of Policies, the definition of reference group was participants who perceived no Policies environmental barriers (policy barriers score = 0).
In the subscale of Service/Assistance, the definition of reference group was participants who perceived no Service/Assistance environmental barriers (services and assistance barriers score = 0).
In the subscale of Attitude/Support, the definition of reference group was participants who perceived no Attitude/Support environmental barriers (attitude and support barriers score = 0).
This included a description of NICE technology appraisal processes, which fell in a period of substantial upgrade and definition of "reference case" analysis by NICE [ 7, 8].
In a future release, however, API plans to replace these solutions with values based on a more rational definition of reference stress.
Definition of reference period.
