Objective: The goal was to create a functional status outcome measure for large outcome studies that is well defined, quantitative, rapid, reliable, minimally dependent on subjective assessments, and applicable to hospitalized pediatric patients across a wide range of ages and inpatient environments.
Methods: Functional Status Scale (FSS) domains of functioning included mental status, sensory functioning, communication, motor functioning, feeding, and respiratory status, categorized from normal (score = 1) to very severe dysfunction (score = 5). The Adaptive Behavior Assessment System II (ABAS II) established construct validity and calibration within domains. Seven institutions provided PICU patients within 24 hours before or after PICU discharge, high-risk non-PICU patients within 24 hours after admission, and technology-dependent children. Primary care nurses completed the ABAS II. Statistical analyses were performed.
Results: A total of 836 children, with a mean FSS score of 10.3 (SD: 4.4), were studied. Eighteen percent had the minimal possible FSS score of 6, 44% had FSS scores of >or=10, 14% had FSS scores of >or=15, and 6% had FSS scores of >or=20. Each FSS domain was associated with mean ABAS II scores (P < .0001). Cells in each domain were collapsed and reweighted, which improved correlations with ABAS II scores (P < .001 for improvements). Discrimination was very good for moderate and severe dysfunction (ABAS II categories) and improved with FSS weighting. Intraclass correlations of original and weighted total FSS scores were 0.95 and 0.94, respectively.
Conclusions: The FSS met our objectives and is well suited for large outcome studies.