Chronic fatigue in patients with unexplained self-reported food hypersensitivity and irritable bowel syndrome: validation of a Norwegian translation of the Fatigue Impact Scale

Figures & data

Table 1 Total and subgroup scores expressed as median and interquartile ranges for the Fatigue Impact Scale, Short-Form Nepean Dyspepsia Index, and subjective health complaints questionnaires in patients with self-reported food hypersensitivity and irritable bowel syndrome (n = 38)

	Median (IQR)
Fatigue Impact Scale
Total score	88.5 (47.8–104.3)
Cognitive function	18.5 (10.0–29.0)
Physical function	24.0 (11.8–30.3)
Psychosocial function	38.5 (16.3–49.0)
Quality of life (SF-NDI)
Total score	27.5 (24.0–37.0)
Tension	5.0 (4.0–8.0)
Interference with daily activities	6.0 (4.0–7.3)
Eating/drinking	7.0 (5.0–9.2)
Knowledge control	4.0 (3.0–6.0)
Work/study	6.0 (2.8–8.0)
Subjective health complaints
Total score	23.0 (14.8–33.5)
Musculoskeletal pain	5.5 (2.0–11.0)
Pseudoneurology	5.0 (2.0–10.0)
Gastrointestinal problems	7.0 (5.0–11.2)
Allergy	2.0 (1.0–4.3)
Influenza	1.0 (0.0–2.3)

Abbreviations: IQR, interquartile range; SF-NDI, Short-Form Nepean Dyspepsia Index.

Table 2 Impact of fatigue in patients with self-reported food hypersensitivity and irritable bowel syndrome in 2008/9 and 2011 (n = 24)

Fatigue Impact Scale	Median (IQR)		Wilcoxon matched-pair signed-rank test	Spearman correlation coefficient, r
	2008/2009	2011
Total score	91.0 (23.8–108.5)	85.0 (18.5–114.0)	P = 0.605	r = 0.67, P = 0.0002
Cognitive	20.5 (10.5–28.8)	20.0 (5.3–27.5)	P = 0.346	r = 0.42, P = 0.020
Physical	24.0 (7.3–28.8)	25.5 (5.3–34.0)	P = 0.457	r = 0.57, P = 0.013
Psychosocial	39.5 (17.5–53.5)	41.5 (8.8–54.2)	P = 1.000	r = 0.42, P = 0.061

Abbreviation: IQR, interquartile range.

Table 3 Demographic data (n, %) for patients with self-reported food hypersensitivity and healthy controls

	Patients (n = 43)	Controls (n = 42)	P-value
Female gender	38 (88)	41 (98)	0.202
Age, years (mean, SD)	41 (16)	47 (12)	0.052
Age <40 years (n, %)	24 (56)	12 (29)	0.015
Employment status (n, %)
Full-time (100%)	14 (33)	33 (79)	<0.0001
Part-time (20%–80%)	7 (16)	9 (21)	0.589
Disability pension	8 (19)
Students	6 (14)
Pensioners	5 (11)
Unemployed	2 (5)
Full-time homemaker	1 (2)

Figure 1 Total and subgroup scores (medians and interquartile ranges) for impact of fatigue in patients with unexplained self-reported food hypersensitivity versus healthy controls (P < 0.0001).