Test-retest reliability of spatial navigation in at-risk Alzheimer’s disease

The Virtual Supermarket Task (VST) and Sea Hero Quest detect high-genetic-risk Alzheimer`s disease (AD). We aimed to determine their test-retest reliability in a preclinical AD population. Over two time points, separated by an 18-month period, 59 cognitively healthy individuals underwent a neuropsychological and spatial navigation assessment. At baseline, participants were classified as low-genetic-risk of AD or high-genetic-risk of AD. We calculated intraclass correlation coefficients (ICC) for all task parameters and used repeated measures ANOVAS to determine whether genetic risk or sex contributed to test-retest variability. The egocentric parameter of the VST measure showed the highest test–retest reliability (ICC=.72), followed by the SHQ distance travelled parameter (ICC=.50). Post hoc longitudinal analysis showed that boundary-based navigation predicts worsening episodic memory concerns in the high-risk (F=5.01, P=0.03), but in not low-risk, AD candidates. The VST and the Sea Hero Quest produced parameters with acceptable test-retest reliability. Further research in larger sample sizes is desirable.