Neurobehavioral Functioning Inventory

The NFI was originally developed as part of the General Health and History Questionnaire, which was used to collect a variety of information on individuals who had experienced a TBI (Kreutzer et al. 1987). The NFI is intended to assess a wide spectrum of behaviours and symptoms encountered in everyday life in order to evaluate the neurological, behavioural and psychological effects of head injury (Kreutzer et al. 1996; Seel et al. 1997; Weinfurt et al. 1999).

The NFI consists of 70 items representing behaviours or symptoms. These are grouped into six functional domains or subscales derived from principal components and factor analytic methodologies (Hart et al. 2003; Seel et al. 1997). The six domains include depression (13 items), somatic (11 items), memory/attention (19 items), communication (10 items), aggression (9 items) and motor (8 items) (Hart et al. 2003; Kreutzer et al. 1996). Six additional, critical items relating to patient safety and community integration have been added to the scale (Kreutzer et al. 1999) to be used in the identification of areas requiring immediate attention (Awad 2002).

Items are rated for frequency of occurrence on a 5-point Likert scale from 1 (never) to 5 (always). While the NFI is a self-rating inventory, it provides for the inclusion of information obtained from suitable proxy sources. The test contains forms for ratings by self and by a significant other. The test takes approximately 20 minutes to complete (Awad 2002). The NFI is a proprietary scale that must be purchased from The Psychological Corporation (Harcourt Assessment, Inc.). 

Table: Characteristics of the Neurobehavioral Functioning Inventory

Advantages. The NFI allows information from collateral sources to be collected, allowing for a more comprehensive picture of both the difficulties experienced by the patient and the impact of problems on the home environment (Witol et al. 1999). Multiple sources of information can improve reliability of information provided through self-report from individuals with TBI who, due to impaired self-awareness, may supply unreliable information (Hart et al. 2003).

Limitations. Awad (2002) was unable to establish construct validity for the NFI. The author cited poor fit indices, a large number of items with poor/weak relation to their latent construct (20 items with squared multiple correlations <0.40), strong correlations between subscales and an inability to distinguish a group of individuals with TBI from non-clinical controls as the basis for this assertion. It is suggested that the NFI may be measuring aspects of a single large construct rather than six discrete constructs.

Weinfurt et al. (1999) reported very low endorsement rates for many of the items resulting in skewed distributions. Low rates of endorsement might indicate that these items are not meaningful discriminators for the head injury population.

While the authors do provide data for comparison, it is not truly normative. The data set used for standardization was derived from a population of individuals with TBI. There is no normative data available based on non-clinical populations (Awad 2002; Witol et al. 1999).

Although the NFI is widely used, there is relatively little information available in the literature with regard to its reliability, validity and responsiveness. The information that is available pertains to older versions of the NFI and, at present, there are no validity or reliability data available for the 76-item version (Awad 2002).

 

Summary- Neurobehavioral Functioning Inventory

Interpretability: Comparative data is provided in the manual stratified by patient age and injury severity. The NFI has been translated into Spanish, German and French. 

Acceptability: The NFI is a lengthy self-report inventory requiring approximately 20 minutes to complete. Forms are provided for assessment by self or by proxy. 

Feasibility: The NFI is a proprietary scale and must be purchased.

 

 Table: Neurobehavioral Functioning Inventory Evaluation Summary

Reliability

Validity

Responsiveness

Rigor

Results

Rigor

Results

Rigor

Results

Floor/ceiling

+

+++ (IC)

+

+

N/A

N/A

N/A

NOTE: +++=Excellent; ++=Adequate; +=Poor; N/A=insufficient information; TR=Test re-test; IC=Internal Consistency; IO=Interobserver; Varied (re. floor/ceiling effects; mixed results).