Clinical dementia diagnoses were defined as confirmed diagnoses of dementia recorded by clinicians following clinical assessment. All memory assessments were then summarised in anonymised case vignettes by the researchers, without making reference to clinical diagnosis. We also removed reference to treatment with acetylcholinesterase inhibitors and memantine. Case vignettes were also produced for assessments preceding and following the diagnosis of dementia, where available.
The case vignettes were then presented to two raters who worked independently to rate the case by applying diagnostic criteria delineated in ICD-10 and DSM-IV-TR; that is, the raters assigned the case to ‘no dementia’ or ‘dementia’ according to either ICD-10 or DSM-IV-TR criteria (Table 1 ). Use of the ICD-10 category of ‘tentative dementia’ was also included.
Raters were also asked to make a separate rating based on their clinical judgement and rate the cases as no dementia, ‘cognitive concern’, ‘possible dementia’ or ‘certain dementia’. Cognitive concern was defined as any evidence of deterioration in cognitive function but where this was of recent onset only and where the rater was unable to exclude a physical causation (such as hypothyroidism) or a mental illness causing changes in behaviour or memory (such as depression). Possible dementia was defined as likely dementia (i.e. significant decline over 6 months or more) but where the raters felt the vignette lacked evidence to be certain of a diagnosis and where they would have wanted further information or to offer another appointment to confirm results and symptoms.
Raters were clinicians (psychiatrists and psychologists) working in the fields of Psychiatry of Intellectual Disability or Psychiatry of Older People who were members of a ‘dementia in intellectual disabilities’ special interest group. Raters remained blinded to the patient’s true clinical diagnosis and any treatment received.
After rating each assessment independently, the raters compared outcomes for each assessment. Where there was disagreement between the raters’ outcomes, a discussion ensued, and a consensus was achieved and recorded. For a subset of assessments, the outcome of each individual rater was recorded prior to consensus allowing for determination of inter-rater reliability.
The case vignettes were then presented to two raters who worked independently to rate the case by applying diagnostic criteria delineated in ICD-10 and DSM-IV-TR; that is, the raters assigned the case to ‘no dementia’ or ‘dementia’ according to either ICD-10 or DSM-IV-TR criteria (
Raters were also asked to make a separate rating based on their clinical judgement and rate the cases as no dementia, ‘cognitive concern’, ‘possible dementia’ or ‘certain dementia’. Cognitive concern was defined as any evidence of deterioration in cognitive function but where this was of recent onset only and where the rater was unable to exclude a physical causation (such as hypothyroidism) or a mental illness causing changes in behaviour or memory (such as depression). Possible dementia was defined as likely dementia (i.e. significant decline over 6 months or more) but where the raters felt the vignette lacked evidence to be certain of a diagnosis and where they would have wanted further information or to offer another appointment to confirm results and symptoms.
Raters were clinicians (psychiatrists and psychologists) working in the fields of Psychiatry of Intellectual Disability or Psychiatry of Older People who were members of a ‘dementia in intellectual disabilities’ special interest group. Raters remained blinded to the patient’s true clinical diagnosis and any treatment received.
After rating each assessment independently, the raters compared outcomes for each assessment. Where there was disagreement between the raters’ outcomes, a discussion ensued, and a consensus was achieved and recorded. For a subset of assessments, the outcome of each individual rater was recorded prior to consensus allowing for determination of inter-rater reliability.
