The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue

Abstract:

The Multidimensional Fatigue Inventory (MFI) is a 20-item self-report instrument designed to measure fatigue. It covers the following dimensions: General Fatigue, Physical Fatigue, Mental Fatigue, Reduced Motivation and Reduced Activity. This new instrument was tested for its psychometric properties in cancer patients receiving radiotherapy, patients with the chronic fatigue syndrome, psychology students, medical students, army recruits and junior physicians. We determined the dimensional structure using confirmatory factor analyses (LISREL’s unweighted least squares method). The hypothesized five-factor model appeared to fit the data in all samples tested (AGFIs > 0.93). The instrument was found to have good internal consistency, with an average Cronbach’s alpha coefficient of 0.84. Construct validity was established after comparisons between and within groups, assuming differences in fatigue based on differences in circumstances and/or activity level. Convergent validity was investigated by correlating the MFI-scales with a Visual Analogue Scale measuring fatigue (0.22 < r < 0.78). Results, by and large, support the validity of the MFI.

 

Source: Smets EM, Garssen B, Bonke B, De Haes JC. The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Psychosom Res. 1995 Apr;39(3):315-25. http://www.ncbi.nlm.nih.gov/pubmed/7636775

 

Sleep disturbances and fatigue in women with fibromyalgia and chronic fatigue syndrome

Abstract:

OBJECTIVE: To determine the relationship between sleep disturbances and fatigue in women with fibromyalgia (FM) and those with chronic fatigue syndrome (CFS) and to assess whether any differences existed between the two groups.

DESIGN: Descriptive comparative.

SETTING: Community program on chronic fatigue syndrome and related disorders.

PARTICIPANTS: Sixty-three women who attended the program; 13 had CFS, and 50 had FM.

MAIN OUTCOME MEASURES: A moderately strong relationship between fatigue and sleepiness was found (r = .63, p < .01). Trouble staying asleep was the highest rated sleep disturbance, and fatigue was the most common subjective feeling reported. Women with CFS reported significantly more trouble staying asleep than women with FM, t(61) = 1.81, p < .03.

CONCLUSIONS: Data from this study support that women with FM and CFS encounter problems sleeping. Clinicians are encouraged to assess women with FM and CFS for their quality of sleep rather than amount of sleep. Researchers are encouraged to continue study of sleep disturbances in women with FM and CFS to improve understanding of the disturbances and to test the effectiveness of sleep interventions.

 

Source: Schaefer KM. Sleep disturbances and fatigue in women with fibromyalgia and chronic fatigue syndrome. J Obstet Gynecol Neonatal Nurs. 1995 Mar-Apr;24(3):229-33. http://www.ncbi.nlm.nih.gov/pubmed/7782955

 

Frequency of deviant immunological test values in chronic fatigue syndrome patients

Abstract:

Of 11 immunological tests done on chronic fatigue syndrome patients and on fatigued controls, 3 tests (protein A binding, Raji cell, or C3 or C4 [deviant values in either complement component were counted as positive]) with deviant results discriminated best among the groups. Other tests, including immunoglobulin G subclasses, complement component CH50, interleukin-2, and anticardiolipin antibodies, did not discriminate well among the groups.

 

Source: Natelson BH, Ellis SP, Braonáin PJ, DeLuca J, Tapp WN. Frequency of deviant immunological test values in chronic fatigue syndrome patients. Clin Diagn Lab Immunol. 1995 Mar;2(2):238-40. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC170136/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC170136/pdf/020238.pdf

 

Fatigue brought on by malfunction of the central and peripheral nervous systems

Abstract:

Increased fatigability necessarily occurs in every patient with muscle weakness, regardless of whether the latter is due to a central or peripheral neurological disorder. The tendency for disuse to increase fatigability, as a secondary phenomenon, must also be considered; disuse affects both motoneuron recruitment and the biochemical and physiological properties of the muscle fibers. In recent studies impaired recruitment has been observed in postpolio patients, while patients with multiple sclerosis or spinal cord injury have shown, in addition, altered neuromuscular function. Findings are also presented in ALS and the chronic fatigue syndrome. In general, the most dramatic increases in fatigability take place in disorders of the peripheral nervous system and almost any cell component can be incriminated. There is a need to study fatigability systematically in neurology and rehabilitation.

 

Source: McComas AJ, Miller RG, Gandevia SC. Fatigue brought on by malfunction of the central and peripheral nervous systems. Adv Exp Med Biol. 1995;384:495-512. http://www.ncbi.nlm.nih.gov/pubmed/8585475

 

Serum levels of carnitine in chronic fatigue syndrome: clinical correlates

Abstract:

Carnitine is essential for mitochondrial energy production. Disturbance in mitochondrial function may contribute to or cause the fatigue seen in chronic fatigue syndrome (CFS) patients. One previous investigation has reported decreased acylcarnitine levels in 38 CFS patients.

We investigated 35 CFS patients (27 females and 8 males); our results indicate that CFS patients have statistically significantly lower serum total carnitine, free carnitine and acylcarnitine levels, not only lower acylcarnitine levels as previously reported. We also found a statistically significant correlation between serum levels of total and free carnitine and clinical symptomatology. Higher serum carnitine levels correlated with better functional capacity.

These findings may be indicative of mitochondrial dysfunction, which may contribute to or cause symptoms of fatigue in CFS patients.

 

Source: Plioplys AV, Plioplys S. Serum levels of carnitine in chronic fatigue syndrome: clinical correlates. Neuropsychobiology. 1995;32(3):132-8. http://www.ncbi.nlm.nih.gov/pubmed/8544970

 

Research about fatigue in France over the past 20 years

Abstract:

The author reported the works of the “Fatigue Studies Group” founded 20 years ago to explore the different dimensions of “fatigue” complaint. The emphasis is placed on the asthenic syndromes evaluation instrument created by the group, which takes into account the socio-demographic data of the patient, clinical signs and their severity as well as the potential etiological factors. Its first version (GEF-3) enabled to isolate 4 groups of asthenia (overworking, somatic, psychosomatic and psychic), each of them requesting a specific treatment. An ulterior version (GEF-4) has been elaborated to describe better the psychiatric semeiology. Finally, a simplified version (GEF-10) was used as an evaluation instrument in different therapeutic researches. At the same time, the group continued its researches on the fatigue psychosocial dimensions and its nosographic status, especially in comparison with dysthymic disorders.

 

Source: Crocq L. Research about fatigue in France over the past 20 years. Encephale. 1994 Nov;20 Spec No 3:615-8. [Article in French] http://www.ncbi.nlm.nih.gov/pubmed/7843059

 

Epidemiologic study of chronic fatigue in primary care (general practice)

Abstract:

The results of a cross sectional study of fatigue in two large samples of patients attending primary care physicians are reported. The level of complaint of fatigue was higher in the prospective sample, which consisted of patients who had been diagnosed as suffering from a viral infection six months earlier. Duration and frequency of experience of fatigue correlated with severity in both samples. Severity, duration and frequency were continuously distributed in these populations.

Attribution of fatigue in these two samples was mixed: social stresses, current physical illness and psychological problems all being offered as explanations. 11% of the cross sectional sample and 17% of the prospective sample met study operational criteria for a possible chronic fatigue state. These patients were assessed in greater detail. The majority had a diagnosable psychiatric disorder, predominantly depression. Physical illnesses were not adequate to explain these fatigue states.

These studies in primary care do not support a clinical entity of a “chronic fatigue syndrome”. Some patients in primary care settings have complaints of fatigue that are both disabling and long lasting, but they do not form a distinct group although the majority are likely however to be suffering from a concurrent psychiatric disorder. In contrast to similar patients with chronic fatigue syndromes attending hospital clinics, primary care patients with complaints of fatigue are much more varied in their ideas of causation with considerable less evidence of disease conviction.

 

Source: Mann AH, Mc Donald E, Cope H, Pelosi A, David A. Epidemiologic study of chronic fatigue in primary care (general practice). Encephale. 1994 Nov;20 Spec No 3:575-9. [Article in French] http://www.ncbi.nlm.nih.gov/pubmed/7843054

 

Fatigue secondary to chronic illness: postpolio syndrome, chronic fatigue syndrome, and multiple sclerosis

Abstract:

Estimates of the percentage of patients with postpolio syndrome, chronic fatigue syndrome, and multiple sclerosis who experience fatigue range from approximately 75% to 100%. In this study we describe the severity of fatigue and its impact on subjects with these three diagnoses.

The Fatigue Severity Scale, the Human Activity Profile, and the Nottingham Health Profile were used to measure fatigue, activity, and health status respectively of each diagnostic group as well as a control group. Using a Kruskal-Wallis one-way analysis of variance followed by a Bonferroni-adjusted Mann Whitney U test all diagnostic groups reported significantly higher levels (p = .0000 to p = .002) of fatigue and lower perceived health status than the control group.

Subjects with chronic fatigue and multiple sclerosis also had significantly reduced activity levels (p = .002 to p = .01) compared with the control group. Further attention should be directed toward understanding the relationship between fatigue and ability to engage in activities as well as strategies for remediation and/or compensation of the fatigue.

 

Source: Packer TL, Sauriol A, Brouwer B. Fatigue secondary to chronic illness: postpolio syndrome, chronic fatigue syndrome, and multiple sclerosis. Arch Phys Med Rehabil. 1994 Oct;75(10):1122-6. http://www.ncbi.nlm.nih.gov/pubmed/7944918

 

Population based study of fatigue and psychological distress

Abstract:

OBJECTIVES: To determine the prevalence of fatigue in the general population and the factors associated with fatigue.

DESIGN: Postal survey.

SETTING: Six general practices in southern England.

SUBJECTS: 31,651 men and women aged 18-45 years registered with the practices.

MAIN OUTCOME MEASURES: Responses to the 12 item general health questionnaire and a fatigue questionnaire which included self reported measures of duration, severity, and causes of fatigue.

RESULTS: 15,283 valid questionnaires were returned, giving a response rate of 48.3%, (64% after adjustment for inaccuracies in the practice registers). 2798 (18.3%) of respondents reported substantial fatigue lasting six months or longer. Fatigue and psychological morbidity were moderately correlated (r = 0.62). Women were more likely to complain of fatigue than men, even after adjustment for psychological distress. The commonest cited reasons for fatigue were psychosocial (40% of patients). Of 2798 patients with excessive tiredness, only 38 (1.4%) attributed this to the chronic fatigue syndrome.

CONCLUSION: Fatigue is distributed as a continuous variable in the community and is closely associated with psychological morbidity.

Comment in:

Patients with a self diagnosis of myalgic encephalomyelitis. [BMJ. 1995]

Twists in the tale of impossible means. The reviewer shows that the gremlins might have attacked on several fronts. [BMJ. 2000]

Twists in the tale of impossible means. In which a copy of the original manuscript is found safe in Norway. [BMJ. 2000]

Fatigue and psychological distress. Statistics are improbable. [BMJ. 2000]

 

Source: Pawlikowska T, Chalder T, Hirsch SR, Wallace P, Wright DJ, Wessely SC. Population based study of fatigue and psychological distress. BMJ. 1994 Mar 19;308(6931):763-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539651/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539651/pdf/bmj00432-0041.pdf

 

Measuring the functional impact of fatigue: initial validation of the fatigue impact scale

Abstract:

The fatigue impact scale (FIS) was developed to improve our understanding of the effects of fatigue on quality of life. The FIS examines patients’ perceptions of the functional limitations that fatigue has caused over the past month. FIS items reflect perceived impact on cognitive, physical, and psychosocial functioning.

This study compared 145 patients referred for investigation of chronic fatigue (ChF) with 105 patients with multiple sclerosis (MS) and 34 patients with mild hypertension (HT). Internal consistency for the FIS and its three subscales was > .87 for all analyses. Fatigue impact was highest for the ChF group although the MS group’s reported fatigue also exceeded that of the HT group. Discriminant function analysis correctly classified 80.0% of the ChF group and 78.1% of the MS group when these groups were compared.

This initial validation study indicates that the FIS has considerable merit as a measure of patient’s attribution of functional limitations to symptoms of fatigue.

 

Source: Fisk JD, Ritvo PG, Ross L, Haase DA, Marrie TJ, Schlech. Measuring the functional impact of fatigue: initial validation of the fatigue impact scale. Clin Infect Dis. 1994 Jan;18 Suppl 1:S79-83. http://www.ncbi.nlm.nih.gov/pubmed/8148458