Abstract
BACKGROUND: Acquired brain injury (ABI) often leads to cognitive impairments, typically measured with cognitive tests in controlled environments. However, cognitive functioning in daily life is likely to fluctuate. This study explored the relationship between traditional subjective and objective cognitive measures and cognitive variability throughout the day and hypothesized that retrospective complaints are more strongly associated with momentary than baseline objective performance, and that greater cognitive variability would relate to higher subjective complaints. It also explored within-person associations between momentary cognitive performance and momentary affect, fatigue, social company and setting. METHODS: We conducted an experience sampling method study among 41 ABI patients. Baseline measures (Checklist for Cognitive and Emotional consequences following stroke, Montreal Cognitive Assessment and Digit Symbol Substitution Test) were administered during a briefing session. Participants responded to seven semi-random daily beeps over seven days using a mobile app. Momentary cognitive performance was assessed with a short digital version of the Digit Symbol Substitution Test. RESULTS: On average, participants completed 79% of beeps. Contrasting our hypothesis, cognitive variability was not associated with retrospective cognitive complaints or baseline cognitive performance. Multilevel analyses showed that momentary concentration complaints (β = 0.10, p = 0.02), fatigue (β = 0.10, p = 0.01) and being away from home (β = 0.23, p = 0.04) were associated with lower momentary cognitive performance. Affect and social company did not significantly impact performance. No between-person effects were found. CONCLUSIONS: Momentary concentration complaints more accurately reflect real-time cognitive performance than retrospective questionnaires. Momentary fatigue impacts real-life cognition after ABI. Measuring cognitive variability can contribute to understanding the cognitive consequences of ABI.