Validity and reliability of the fatigue impact scale in stroke

ABSTRACT

Background

Fatigue is one of the significant problems of post-stroke patients as it causes a decreased quality of life. Although the fatigue impact scale (FIS) is used in stroke, it lacks validation studies.

Objective

This study evaluates the psychometric properties of the FIS in patients with stroke.

Subjects and Methods

A total of 41 subjects with stroke and 41 control subjects admitted to Physical Medicine and Rehabilitation Department were included. Convergent validity was assessed using the SF-36 vitality (SF-36 v) scale and the fatigue severity scale (FSS). Divergent validity was assessed using the Hospital Anxiety and Depression Scale (HADS).

Results

All subscores of the FIS were significantly higher in the stroke group than in the control group (p < .05). FIS showed excellent internal consistency in stroke patients (Cronbach’s alpha = 0.946). There was a negative correlation among FIS and SF-36 v (r = −0.506, p = .001), and a positive correlation between the HADS anxiety score (r = 0.356, p = .026) and the HADS depression score (r = 0.293, p = .071). FIS total scores were weakly correlated with the FSS (r = 0.323, p = 0.039). The test-retest reliability of FIS was good in terms of its cognitive, physical, and psychosocial subscales and total scores, with ICC values of 0.78, 0.73, 0.80, and 0.83, respectively.

Conclusion

FIS is a valid and reliable multidimensional scale that sensitively discriminated fatigue in the stroke patients from that in the control subjects.

KEYWORDS:

• Fatigue
• stroke
• validity and reliability
• fatigue impact scale
• psychometric feature

Author contributions

Study concept and design: Ozden Ozyemisci Taskiran, Gulcin Kaymak Karatas

Induction of subjects into the study, acquisition of data: Ozden Ozyemisci Taskiran, Elif Balevi Batur, Mustafa Cengiz

Analysis and interpretation of data: Elif Balevi Batur, Selcen Yuksel Ozden Ozyemisci Taskiran

Drafting and revising the manuscript for intellectual content: Elif Balevi Batur, Ozden Ozyemisci Taskiran

Final approval of manuscript: All authors

Author Disclosures

All authors have participated in this project.

Declaration of interest

The authors report no conflicts of interest.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

No funds were received in support of this work.