Test–Retest Norms and Reliable Change Indices for the MicroCog Battery in a Healthy Community Population Over 50 Years of Age

Abstract

The increasing availability of computerized test batteries used to assess neuropsychological changes requires the availability of suitable test-retest normative data. Reliable change indices can then be used to evaluate significance of change in an individual's performance on retesting. We tested (N = 40) neurologically normal adults on three occasions (initially, two weeks, and three months) on the MicroCog: Assessment of Cognitive Functioning computerized testing instrument. Normative retest data are presented for two analytic techniques: the Reliable Change Index adjusted for practice and the Standardized Regression-Based technique. At two weeks, the correlation coefficients ranged from .49 to .84, with all scores demonstrating significant practice effects. At 3 months, coefficients ranged from .50 to .83, with all scores except Attention / Mental Control demonstrating significant practice compared to baseline. Regression equations were generated for all scores using age, sex, education level, and score at Time 1 as predictors. For all measures the only significant predictor was the Time 1 score. The reliable change indices and regression equations presented here can be used to determine the significance of change from predicted retest scores in a matched interventional cohort.