Comparing Four-Point and Five-Point Scales in the Norwegian Function Assessment Scale
Author Information
Author(s): Østerås Nina, Gulbrandsen Pål, Garratt Andrew, Benth Jūratë Šaltytë, Dahl Fredrik A, Natvig Bård, Brage Søren
Primary Institution: University of Oslo
Hypothesis
This study aimed to compare the original four-point scale with the new five-point scale version of the Norwegian Function Assessment Scale (NFAS) by evaluating its validity in a population.
Conclusion
The five-point scale version of the NFAS demonstrated better data quality and internal consistency, suggesting it should be used in future applications.
Supporting Evidence
- Both versions of the NFAS had acceptable response rates and good data quality.
- The five-point scale version had better data quality in terms of missing data and internal consistency.
- Construct validity was acceptable for both versions, as shown by correlations with other health assessment instruments.
- The NFAS-5 demonstrated significantly higher internal consistency compared to the NFAS-4.
- Both versions discriminated well between groups with different levels of health status.
Takeaway
This study looked at two different ways to ask people about their ability to do things, and found that using five options instead of four helps people give better answers.
Methodology
Participants were randomly assigned to receive either the four-point or five-point scale version of the NFAS through postal questionnaires.
Potential Biases
Self-reported data may lead to response bias, and the lack of a 'not applicable' option may have affected the results.
Limitations
The study had a moderate response rate and all data were self-reported, which may introduce bias.
Participant Demographics
The study included inhabitants from seven birth cohorts in Ullensaker municipality, Norway, with no major demographic differences from the general population.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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