Abstract
Objective: Cognitive intraindividual variability (IIV) reflects fluctuations in cognitive test performance, which may be associated with poorer everyday functioning. This study adopted a retrospective conceptual replication approach to determine whether higher IIV dispersion is associated with poorer financial management skills. Method: Study 1 participants were 112 adults with (n = 76) and without (n = 36) HIV who completed an in-person assessment that included the Cogstate battery, the Web-based Evaluation of Banking Skills (WEBS), and the UCSD Performance-Based Skills Assessment Brief Version (UPSA-B). Study 2 participants were 120 younger (n = 60) and older (n = 60) adults who completed a brief clinical neuropsychological battery, the Telephone-based Daily Instrumental Activities of Living (T-DIAL), and the money management subscale of the Independent Living Scale (ILS) via telephone. IIV dispersion was derived from the normed T-scores of the cognitive tests using the coefficient of variance (i.e., intra-individual standard deviation divided by the intra-individual mean). Results: At the univariate level, higher IIV dispersion was significantly associated with lower scores on all financial management measures at broadly medium effect sizes (ps < .05), which did not differ meaningfully across studies or measures (ps > .05). Multiple regression analyses showed that higher IIV dispersion was independently associated with lower total scores on WEBS, UPSA-B Financial Skills, and ILS Money Management (ps < .05), but not T-DIAL (p = .184). Conclusions: Findings across two samples with varying methodologies support the hypothesis that greater IIV in cognitive performance may interfere with the ability to manage finances in daily life, but questions remain regarding the incremental value of IIV dispersion relative to global cognition.