NFI Properties

Evaluation of the psychometric properties of the NFI have been reported extensively (Kreutzer, Seel, & Marwitz, 1999; Kreutzer, Marwitz, Seel, & Serio, 1996; Seel, Kreutzer, & Sander, 1997). The first version of the inventory included 105 items organized into five categories based on content area. Early experience with the questionnaire provided support for face validity. The pattern of NFI responses closely paralleled the pattern reported by other researchers characterizing the broad spectrum of brain injury sequelae (Kreutzer, Devany, Myers, & Marwitz, 1991).

A factor analysis study was completed using responses from 520 individuals (Kreutzer, Marwitz, Seel, & Serio, 1996). Six factors were revealed: Somatic Difficulties, Memory/Attention Difficulties, Communication Deficits, Aggressive Behaviors, Motor Impairment, and Depression. Internal consistency was demonstrated using Cronbach's alpha statistic. Criterion-related validity was established by demonstrating that NFI responses were correlated with standardized neuropsychological and personality measures reflecting patients' status (Kreutzer, Marwitz, Seel, & Serio, 1996). Later research indicated high levels of agreement between family members and patients (Seel, Kreutzer, & Sander, 1997). Sander and colleagues (Sander, Kreutzer, & Fernandez, 1997) demonstrated that the questionnaire distinguished between persons who were employed and persons who were unemployed after brain injury. The NFI has also been helpful in characterizing the long-term sequelae of injury (e.g., 5 to 35 years postinjury; Witol, Sander, Seel, & Kreutzer, 1996).