Ratcliff G, Dodge HH, Birzescu MA, Ganguli M. Tracking
cognitive functioning over ten years of followup of a rural elderly community
population. Applied Neuropsychology, 10: 76-88, 2003.
Over 10 years, a community-based sample age 65> or = years, with a starting
cohort size of 1,206, was assessed biennially with the Mini-Mental State Exam;
the Consortium to Establish a Registry for Alzheimer's Disease battery;
Immediate and Delayed Recall of a Story; Verbal Fluency for P and S, Fruits
and Animals; Clock Drawing; Temporal Orientation; and Trail Making tests. We
report distributions of scores over time, at each wave, in (a) all individuals
who were assessed at that wave, whether or not they participated in all waves,
and (b) the Survivor subgroup of 425 participants who completed all tests at
all 5 waves. Scores and factor structures remained remarkably stable over the
study period. The most marked decline over time was seen on the Trail Making
tests. As the survivors are de facto a largely healthy and motivated group,
their data can be considered population-based healthy norms and may serve as a
reference for other studies conducting repeated evaluations using the same
tests.