Tablet-Based Assessment of Picture Naming in Prodromal Alzheimer's Disease: An Accessible and Effective Tool for...

Introduction: Effective mild cognitive impairment (MCI) screening requires accessible testing. This study compared two tests for distinguishing MCI patients from controls: rapid automatized naming (RAN) for naming speed and low-contrast letter acuity (LCLA) for sensitivity to low-contrast letters.

Two RAN tasks were used: the Mobile Universal Lexicon Evaluation System (MULES, picture naming) and the Staggered Uneven Number test (SUN, number naming). Both RAN tasks were administered on a tablet and in a paper/pencil format. The tablet format was administered using the Mobile Integrated Cognitive Kit application. LCLA was tested at 2.5% and 1.25% contrast.

Sixty-four participants (31 MCI, 34 controls; mean age 73.2 ± 6.8 years) were included. MCI patients were slower than controls for paper/pencil (75.0 vs. 53.6 s, p < 0.001), and tablet MULES (69.0 s vs. 50.2 s, p = 0.01). The paper/pencil SUN showed no significant difference (MCI: 59.5 s vs. controls: 59.9 s, p = 0.07) nor did the tablet SUN (MCI: 59.3 s vs. controls: 55.7 s, p = 0.36). MCI patients had worse performance on LCLA testing at 2.5% contrast (33 letters vs. 36, p = 0.04*) and 1.25% (0 letters vs. 14 letters, p < 0.001). Receiver operating characteristic (ROC) analysis showed similar performance of paper/pencil and tablet MULES in distinguishing MCI from controls (area under the ROC curve [AUC] = 0.77), outperforming both SUN (AUC = 0.63 paper, 0.59 tablet) and LCLA (2.5% contrast: AUC = 0.65, 1.25% contrast: AUC = 0.72).

The MULES, in both formats, may be a valuable screening tool for MCI.