WAVES: A Novel Test to Evaluate Visuospatial Construction Ability in a School-aged Population.

Abstract

Objective: The paucity of valid diagnostic tools is one of the challenges preventing the effective implementation of child cognitive health testing in Sub-Saharan developing countries. WAVES addresses the need for new psychometric tests to evaluate visuospatial construction ability in a school-aged population. WAVES involves the standardized administration of a copy design task that is sequentially repeated by four distinct reproduction modalities: copy design with open eyes (CDO), immediate reproduction from memory with open eyes (IRMO), immediate reproduction from memory with closed eyes (IRMC), and delayed reproduction from memory with closed eyes (DRMC).

Design: WAVES reliability and validity were assessed in a field trial using Classical Test Theory or Item Response Theory (IRT) methods. A total of 445 children, aged 5 to 17 years old, were recruited at multiple Zambian clinical sites and schools.

Results: WAVES provides a visuographomotor construction processing (VGCP) index and three subscale inaccuracy of reproduction scores: perseveration, decreased spacing, and changing direction difficulty (CDD). WAVES scores depended on age and showed an age-related increase of reproduction accuracy. Altered visuospatial construction, as indicated by higher scores, was associated with poor health status (i.e., chronic neurologic or medical disease or prolonged exposure to psychosocial stress and deprivation). Reliability estimates, expressed as an intraclass correlation coefficient (ICC; 95% confidence interval [CI]), at test-retest (n=86) were: VGCP Index: 0.94 (0.91, 0.96); perseveration: 0.76 (0.62, 0.84); decreased spacing: 0.86 (0.79, 0.91); and CDD: 0.93 (0.89, 0.95).

Conclusion: WAVES has potential for clinical utility in evaluating the effect of different health conditions on visuospatial construction ability. Study results warrant further research to validate its use in healthcare and clinical research settings.