Analyzing the relationship between processing speed impairment and Rey-15 item test performance

Objective: This study investigated the relationship between processing speed impairment severity and performance on the Rey 15-Item Test (RFIT) and RFIT + Recognition.

Method: Cross-sectional data from 285 examinees (228 valid/57 invalid) referred for neuropsychological assessment who were administered the RFIT, Weschler Adult Intelligence Scale-Fourth Edition (WAIS-IV) Processing Speed Index (PSI), Brief Visuospatial Memory Test - Revised, Rey Auditory Verbal Learning Test, and three independent criterion PVTs were included. PSI bands were operationalized as Intact (≥85SS; n = 163), Reduced/Possibly Impaired (77-84SS; n = 36), or Impaired (≤76 SS; n = 29). Receiver operator characteristic (ROC) curve analyses tested the RFIT and RFIT + Recognition's classification accuracy for detecting invalid performance for the overall sample and by PSI impairment status.

Results: Those with intact processing speed performed significantly better on the RFIT and RFIT + Recognition than those with reduced/possibly impaired and impaired processing speed. Though verbal/visual memory predicted RFIT scores independently, PSI contributed additional variance. ROC curves for RFIT and RFIT + Recognition were significant (AUC=.64-.84). Optimal cut-scores yielded modest sensitivity (30%-63%) and high specificity (89%-93%) among those with intact and reduced processing speed but yielded unacceptable accuracy in those with impaired speed (AUC=.59-.62).

Conclusions: Although the RFIT and RFIT + Recognition demonstrated acceptable classification accuracy in those with intact processing speed, accuracy diminished with increasing speed impairment. This finding was more pronounced for RFIT + Recognition compared to the traditional RFIT. As such, the RFIT may have limited clinical utility in examinees with more significant processing speed deficits.