Processing speed and executive function in pediatric acute lymphoblastic leukemia survivors

This study examined processing speed and executive function late effects in survivors of pediatric ALL (hereafter referred to as Survivors). Late effects are long-term, treatment-related health problems associated with the neurotoxic side-effect of cancer treatment on brain development. Processing speed —mental and motor speed with which a person can solve nonverbal problems — was estimated via an composite of processing speed attained from several measures of processing speed. Executive function — a collection of processes orchestrated in the performance of purposeful, goal-directed behavior — was measured using the Parent and Teacher forms of the Behavior Rating Inventory of Executive Function (BRIEF). This study also explored the effect of previously identified risk factors for processing speed and executive function late effects. Finally, executive function late effects were further explored via the use of performance-based measures, including the Tower and Trail Making (Condition 4) tests of the Delis-Kaplan Executive Function System (D-KEFS).
Hypotheses included (1) Survivors would demonstrate significantly poorer processing speed; (2) late effects risk factor variables (i.e., greater elapsed time since completion of treatment, lower age at diagnosis, and higher intensity of treatment) would predict poorer processing speed; (3) female gender would predict poorer processing speed; (4) parents and teachers would demonstrate both low interrater agreement (Hypothesis 4a) and differ significantly in the severity (Hypothesis 4b) of their ratings of Survivor executive function; (5) parent and teacher ratings of executive function would indicate significantly poorer Survivor metacognition (Hypothesis 5a), whereas Survivor behavioral regulation would not differ significantly (Hypothesis 5b); (6) risk factor variables would predict poorer Parent and Teacher ratings of Survivor metacognition; (7) female gender would predict poorer Parent and Teacher ratings of Survivor metacognition; (8) survivor processing speed and Parent and Teacher ratings of executive function would exhibit a positive relationship; and (9) poorer Survivor processing speed would predict poorer parent and teacher ratings of executive function. Results provided support for hypothesis 1 and 5a. Partial support was obtained for hypotheses 4a, 4b, and 7. Hypotheses 2, 3, 5b, 6, 8, and 9 were not supported.