Sly Saint
Senior Member (Voting Rights)
(Mods, do what you will with this.)
This paper from 1998 is regularly cited in various papers as showing that the CFQ is a reliable measure for CFS research.
But read beyond the abstract..........
https://www.sciencedirect.com/science/article/abs/pii/S0022399998000221
so they were recruiting for a trial
http://sci-hub.tw/https://doi.org/10.1016/S0022-3999(98)00022-1#
This paper from 1998 is regularly cited in various papers as showing that the CFQ is a reliable measure for CFS research.
But read beyond the abstract..........
Abstract
The Chalder fatigue scale is widely used to measure physical and mental fatigue in chronic fatigue syndrome patients, but the constructs of the scale have not been examined in this patient sample. We examined the constructs of the 14-item fatigue scale in a sample of 136 chronic fatigue syndrome patients through principal components analysis, followed by correlations with measures of subjective and objective cognitive performance, physiological measures of strength and functional work capacity, depression, anxiety, and subjective sleep difficulties. There were four factors of fatigue explaining 67% of the total variance. Factor 1 was correlated with subjective everyday cognitive difficulties, concentration difficulties, and a deficit in paired associate learning. Factor 2 was correlated with difficulties in maintaining sleep. Factor 3 was inversely correlated with grip strength, peak VO2, peak heart rate, and peak functional work capacity. Factor 4 was correlated with interview and self-rated measures of depression. The results support the validity of mental and physical fatigue subscales and the dropping of the “loss of interest” item in the 11-item version of the fatigue scale.
https://www.sciencedirect.com/science/article/abs/pii/S0022399998000221
Inclusion criteria specified that patients had to meet operationalized “Oxford” research criteria for CFS [2
The distribution of the 14 items of the fatigue scale in the 136 CFS patients was examined. Scores on eight items were normally distributed, but six items (“tiredness,” “resting more,” “lacking energy,” “feeling weak,” “feeling sleepyor drowsy,” and “starts things without difficulty but gets weaker as goes on”) were highly skewed with the majority of patients reaching the maximum score.
RESULTS
Two hundred twenty-seven patients were assessed for eligibility into a treatment
trial of graduated aerobic exercise and fluoxetine
so they were recruiting for a trial
Sixty-two did not fulfill criteria for CFS. Of the remaining 165, 25 did not consent
to the treatment trial, 3 could not come off antidepressants, and 1 required other
medical treatment first. The 136 CFS patients not taking psychotropic medication
who started the treatment trial completed the assessments examined in the current
study. Physiological assessments were missed for four patients: three because they
dropped out during the initial assessment, and one with no meaningful measure-
ments. Nine patients failed to complete their sleep assessments.
The mean (SD) age of the total sample was 39 (11) years, median (interquartile
range) duration of CFS symptoms was 28 (40) months, and median (interquartile
range) education was 11 (1) years. There were 97 (71%) females, 83 (61%) were
married or cohabiting, and 29 (21%) were currently in paid employment. Sixty-two
patients (46%) fulfilled DSM-III-R criteria [6] for a psychiatric diagnosis: 14 (10%)
had major depression; 32 (24%) either dysthymia or depressive disorder not other-
wise specified; 14 (10%) various anxiety disorders; and 2 (2%) somatization disor-
der.
The 50 patients who took part in the cognitive testing were older than the rest of the sample
Near-maximal scoring on six physical fatigue scale items from the total of 14
items constituting the Chalder fatigue scale supports the validity of scoring the
physical fatigue scale on a two-point scale (presence or absence) rather than the
four-point Likert scoring. Most of the variance in the total fatigue scale is thus ac-
counted for by the mental fatigue score.
There are a number of methodological issues that need to be addressed. The sub-
jects in our study were volunteers for a randomized, controlled trial and differing
constructs might apply to a sample of all attenders with CFS at a medical clinic
http://sci-hub.tw/https://doi.org/10.1016/S0022-3999(98)00022-1#