Effects of examiner error on neuropsychological test results in a multi-site study.

This study compared the difference between original and "corrected" neuropsychological test scores at baseline and following 1 year of experience in 17 non-psychology trained examiners. Test protocols were reviewed for errors in instruction, administration, recording, and scoring. Fewer than 3% of the test scaled scores showed a correction of greater than 1 SD. At baseline, individual test scores that changed T-score classification occurred on Digit Symbol, Trails B, and Logical Memory I and II. At one year, significant classification changes remained for Logical Memory I and II (25% and 15%). Scoring of subjective tests remains problematic and centralized re-scoring is recommended.