(344) Functional Status Scale Score Compared to Neurodevelopmental Testing in Traumatic Brain Injury

Introduction: Neurodevelopmental monitoring is essential to research in children with traumatic brain injury. The Functional Status Scale (FSS) was created as an objective, rapid assessment of patients’ abilities to perform activities of daily living while inpatient. It has since been applied to monitoring functional outcomes after hospital discharge. Limited data compares outpatient deficits observed via FSS to neurodevelopmental testing. It is imperative to understand the differences between FSS and these assessments to interpret outcomes research using the FSS. We hypothesize that FSS underestimates motor and language deficits.

Methods: Data was obtained from a single center retrospective cohort study conducted from January 2016 to March 2023. Eligible subjects were less than age 3, admitted with moderate to severe head trauma, and had follow up within 1 year of discharge with neuropsychology and neurology or physical medicine (PMNR). Motor and communication FSS scores were compared to composite motor and language results from the Bayley Scales of Infant and Toddler Development 3rd edition. Developmental delay was defined as below the 15th percentile for age (1 standard deviation) in the Bayley or FSS > 1. FSS and Bayley results were paired if data was obtained within 2 months of each other. Using the Bayley as a standard, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FSS were calculated.

Results: There were 34 pairings of Bayley and FSS scores. The mean age of subjects was 10.5 months ± 7 months. For Motor FSS > 1 the sensitivity and specificity were 78.5% and 95.7% respectively, with a PPV of 91.7% and a NPV of 88%. For Communication FSS > 1 the sensitivity and specificity were 71.4% and 100% respectively, with a PPV of 100% and a NPV of 92.6%. In both groups, Bayley scores ranged from the 1st to >90th percentile when FSS = 1.

Conclusions: In both motor and communication, FSS >1 was highly predictive of delay with good specificity. However, individuals with delay may be missed. A wide range of Bayley results were observed in subjects with FSS 1. Interpretation is limited by the low number of observations. Additionally, the interpretation of neurodevelopmental testing must be contextualized by neuropsychologists performing the testing.