Measuring Physical and Cognitive Fatigue in People With Post-Polio Syndrome: Development of the Neurological Fatigue Index for Post-Polio Syndrome (NFI-PP)

Testing the psychometric properties of the Chinese version of the Neurological Fatigue Index-Stroke

OBJECTIVE

To test the psychometric properties of a Chinese version of the Neurological Fatigue Index-Stroke (C-NFI-Stroke) in stroke survivors.

DESIGN

This was a validation study. Cross-cultural adaptation of the scale was conducted according to standard guidelines. Reliability, validity, responsiveness, and interpretability were measured.

SETTING

Self-help groups and a community center.

SUBJECTS

One hundred and twelve Chinese stroke survivors and 65 healthy Chinese older people living in the community.

INTERVENTIONS

Not applicable.

MAIN MEASURES

The C-NFI-Stroke, Fatigue Severity Scale, Mental Fatigue Scale, General Self-Efficacy Scale, and Geriatric Depression Scale were used.

RESULTS

Cronbach's α coefficients were 0.69-0.88; the item-level agreement was 70.4%-88.9%; the weighted Kappa value was 0.47-0.79; and the intra-class correlation coefficients were 0.88-0.93. The C-NFI-Stroke had no ceiling and floor effects. It had good content validity and had two factors, "lack of energy" and "tiredness/weakness." The confirmatory factor analysis showed a good fit to the model. The C-NFI-Stroke significantly correlated with existing fatigue scales (r_s = 0.55-0.63), self-efficacy (r_s = -0.31 to -0.37), and depressive symptoms (r_s = 0.53-0.60). The C-NFI-Stroke could discern differences between stroke survivors and healthy older people.

CONCLUSIONS

The C-NFI-Stroke is a reliable and valid tool for clinical and research use on people who have been diagnosed with stroke for a year or more, although its factor structure differs from that of the original English version.