Estimating severity of illness and disability in Frontotemporal Dementia: Preliminary analysis of the Dementia Disability Rating (DDR).
BACKGROUND
Current measures of severity and disability do not stage or track the progression of disability in frontotemporal dementia (FTD) well. We investigated the reliability of the newly developed Dementia Disability Rating (DDR) in the measurement and staging of illness severity in FTD and dementia of the Alzheimer type (DAT).
We studied 48 consecutive patients of the Johns Hopkins FTD and Young-Onset Dementias Clinic, with diagnoses of DAT, FTD, vascular dementia and "other" cognitive disorder (CDNOS). Cases were scored on the CDR and DDR by three trained raters, based on neuropsychiatric examinations performed at first visit and other assessments performed within the preceding year. Consensus ratings were assigned in conference.


RESULTS
Inter-rater correlations of DDR sum of ranks scores for DAT ranged from 0.88 to 0.91, for FTD 0.89-0.96 and for CDNOS 0.85-0.97. Similar correlations were observed of the CDR sum of rank scores for DAT and FTD. Correlations of DDR summary scores for DAT were 0.67-0.91 and for FTD 0.79-0.91, as compared to CDR data: 0.87-0.92 (p<0.0001) and 0.80-0.93 (p<0.0001) for DAT and FTD respectively. In DAT patients the correlation between CDR and DDR summary scores was higher than in FTD patients, whereas correlations based on sum of ranks scores were high in both groups.


CONCLUSIONS
These preliminary data indicate the DDR measures disability in DAT and FTD, with reliability comparable to the CDR. Convergent validity was demonstrated for the DDR.
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine.
Chiadi U
CU
Onyike
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine.
Kelly L
KL
Sloane
Division of Movement Disorders, Department of Neurology, Johns Hopkins University School of Medicine.
Shawn F
SF
Smyth
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine.
Brian S
BS
Appleby
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine ; Abarbanel Mental Health Centre, Bat Yam, Israel.
David M
DM
Blass
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine.
Peter V
PV
Rabins