Oral Symbol Digit - Standardized Score?
David Gonzalez — Aug 16, 2019 11:25PM UTC
Two questions in regard to the Oral Symbol Digit Test (OSDT):
First, even through there is descriptive data for the OSDT in the technical manual, no standardized score of any sort is provided after administration. Is there a reason why? It seems like it would be very easy to provide some sort of standardized score. If there is concern about small-n cells for "complete" demographic correction, a simple age-adjusted standardized score would be preferable to no standardized score at all.
Second, it appears that the OSDT is supplemental measure given to a subsample of the normative sample. This subsample is not adequately described (e.g., region of the country? Census-matched?). Also, the OSDT was not described in the Weintraub et al Neurology paper. Were there reliability and validity studies with it, such as convergence with DSST, SDMT, etc.?
Any info on the above two topics is much appreciated!
1 Community Answers
Cindy Nowinski - Aug 29, 2019 at 09:22PM UTC
My Company Agent
Thank you for your inquiry and I apologize for the delayed response.
The Cognition team did not feel the sample size was adequate or representative to produce any normative scores for OSDT in 2012. However, all of the norming data (and much validation data too) is available in the Dataverse which can be reached via the link below.
You are welcome to use the data there to develop score(s) for OSDT. (If you do, we’d be interested in seeing what you come up with). You can also determine the demographics of the subsample that took the OSDT using the norming data in Dataverse. You are correct in that we do not provide that information.
The primary interest in including OSDT in the NIHTB was to provide a motor-free (reduced?) processing speed measure for use if needed. We did not conduct any extensive psychometric evaluation, as the paradigm has been frequently evaluated in the literature. In our next version of NIHTB, we hope to have full national norms for this measure, as well as some convergence data. However, as of now the only possible comparative reference in the NIHTB itself would be Pattern Comparison .
I hope this is useful.
Cindy Nowinski, MD, PhD