A simple test of central processing speed: an extension of the Short Blessed Test.

OBJECTIVE: To evaluate the efficacy and reliability of a simple measure of central processing speed: the time to recite the months of the year in reverse order, from the Short Blessed Test of Orientation, Concentration, and Memory (SBT).
DESIGN: Cross-sectional and longitudinal designs were used to establish validity and test-retest reliability.
SETTING: Participants' homes and by telephone interview. PARTICIPANTS: An age-stratified sample of 120 community-dwelling women, aged 67-94, randomly selected from Medicare recipients of the St. Louis Metropolitan Statistical Area. MEASUREMENTS: Dependent variables were the SBT, the Trail Making Test, computer-generated simple and choice reaction time, and time to say the months of the year backward (TMYB). The independent variable was age.
RESULTS: Significant Pearson product-moment correlations were obtained for Trail Making and TMYB with a simple and choice reaction time after controlling for age and cognitive status. An exponential relationship was observed between age and TMYB, expressed both cross-sectionally and as rate of change. Test-retest reliability for TMYB was 0.90.
CONCLUSIONS: TMYB is a valid and reliable measure of central processing speed that compares favorably to the more elaborate and time-consuming Trail Making B test. Because of its simplicity and ease of administration, this test provides the clinician with a practical measure of central processing speed. TMYB extends the utility of the widely used Short Blessed Test by measuring this additional and important domain of brain function.