An investigation into the psychometric properties of the Hospital Anxiety and Depression Scale in individuals with chronic fatigue syndrome

Abstract:

The study sought to determine the psychometric properties of the Hospital Anxiety and Depression Scale (HADS) in individuals with chronic fatigue syndrome (CFS) assessed using a web-based data collection tool. Exploratory and confirmatory factor analyses were conducted on the HADS to determine its psychometric properties in 117 individuals with CFS. Seven models were tested to determine model fit to the data.

Internal reliability estimations of the anxiety and depression sub-scales were found to be acceptable, however, a three-factor model was found to provide a significantly better fit to the data when compared to the bi-dimensional two-factor structure previously assumed to underpin the HADS’ construct validity.

The clinical utility of the HADS in the assessment of anxiety and depression in CFS appears to be fundamentally compromised by the presence of a three-dimensional underlying factor structure. Future revision of the HADS is recommended if the instrument is to be used reliably to screen CFS patients.

 

Source: McCue P, Martin C, Buchanan T, Rodgers J, Scholey A. An investigation into the psychometric properties of the Hospital Anxiety and Depression Scale in individuals with chronic fatigue syndrome. Psychol Health Med. 2003 Nov;8(4):425-39. doi: 10.1080/1354850310001604568. http://www.ncbi.nlm.nih.gov/pubmed/21974733

 

Life events, difficulties and dilemmas in the onset of chronic fatigue syndrome: a case-control study

Abstract:

BACKGROUND: The role of stress in the onset of chronic fatigue syndrome is unclear. Our objectives in this study were first, to determine the relation between the onset of chronic fatigue syndrome and stressful life events and difficulties. Secondly, we examined the role of a particular type of problem, dilemmas, in the onset of chronic fatigue syndrome.

METHOD: We used a case-control design with 64 consecutive referrals from an Infectious Diseases/ Liaison Psychiatry Fatigue clinic and 64 age- and sex-matched controls from a general practice population control group in Leeds. We had two main outcome measures; the odds ratios of the risk of developing chronic fatigue syndrome after experiencing a severe life event, severe difficulties or both in the year and 3 months preceding onset; and the proportion of subjects in each group who experienced a dilemma prior to onset.

RESULTS: Patients with chronic fatigue syndrome were more likely to experience severe events and difficulties in the 3 months (OR = 9, 95% CI 3.2 to 25.1) and year (OR = 4.3, 95% CI 1.8 to 10.2) prior to onset of their illness than population controls. In the 3 months prior to onset 19 of the 64 patients (30%) experienced a dilemma compared to none of the controls.

CONCLUSIONS: Chronic fatigue syndrome is associated with stressful events and difficulties prior to onset. Those events and difficulties characterized as being dilemmas seem to be particularly important.

 

Source: Hatcher S, House A. Life events, difficulties and dilemmas in the onset of chronic fatigue syndrome: a case-control study. Psychol Med. 2003 Oct;33(7):1185-92. http://www.ncbi.nlm.nih.gov/pubmed/14580073

 

Illness perceptions and levels of disability in patients with chronic fatigue syndrome and rheumatoid arthritis

Abstract:

OBJECTIVE: To investigate the strength of chronic fatigue syndrome (CFS) patients’ negative illness perceptions by comparing illness perceptions and self-reported disability in patients with CFS and rheumatoid arthritis (RA).

METHODS: Seventy-four RA patients and 49 CFS patients completed the Illness Perception Questionnaire-Revised and the 36-item Short-Form Health Survey.

RESULTS: When compared to the RA group, the CFS group attributed a wider range of everyday somatic symptoms to their illness, perceived the consequences of their illness to be more profound and were more likely to attribute their illness to a virus or immune system dysfunction. Both groups reported equivalent levels of physical disability but the CFS group reported significantly higher levels of role and social disability.

CONCLUSION: Although the symptoms of CFS are largely medically unexplained, CFS patients have more negative views about their symptoms and the impact that these have had on their lives than do patients with a clearly defined and potentially disabling medical condition. The data support the cognitive behavioural models of CFS that emphasise the importance of patients’ illness perceptions in perpetuating this disorder.

 

Source: Moss-Morris R, Chalder T. Illness perceptions and levels of disability in patients with chronic fatigue syndrome and rheumatoid arthritis. J Psychosom Res. 2003 Oct;55(4):305-8. http://www.ncbi.nlm.nih.gov/pubmed/14507540

 

Distinguishing patients with chronic fatigue from those with chronic fatigue syndrome: a diagnostic study in UK primary care

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has been defined, but many more patients consult in primary care with chronic fatigue that does not meet the criteria for CFS. General practitioners (GPs) do not generally use the CFS diagnosis, and have some doubt about the validity of CFS as an illness.

AIM: To describe the proportion of patients consulting their GP for fatigue that met the criteria for CFS, and to describe the social, psychological, and physical differences between patients with CFS and those with non-CFS chronic fatigue in primary care.

DESIGN OF STUDY: Baseline data from a trial of complex interventions for fatigue in primary care.

SETTING: Twenty-two general practices located in London and the South Thames region of the United Kingdom recruited patients to the study between 1999 and 2001.

METHOD: One hundred and forty-one patients who presented to their GP with unexplained fatigue lasting six months or more as a main symptom were recruited, and the Centers for Disease Control (CDC) case definition was applied to classify CFS.

RESULTS: Approximately two-thirds (69%) of patients had chronic fatigue and not CFS. The duration of fatigue (32 months) and perceived control over fatigue were similar between groups; however, fatigue, functioning, associated symptoms, and psychological distress were more severe in the patients in the CFS group, who also consulted their GP significantly more frequently, were twice as likely to be depressed, and more than twice as likely to be unemployed. About half (CFS = 50%; chronic fatigue = 55%) in each group attributed their fatigue to mainly psychological causes.

CONCLUSIONS: In primary care, CFS is a more severe illness than chronic fatigue, but non-CFS chronic fatigue is associated with significant fatigue and is reported at least twice as often. That half of patients, irrespective of CFS status, attribute their fatigue to psychological causes, more than is observed in secondary care, indicates an openness to the psychological therapies provided in that setting. More evidence on the natural history of chronic fatigue and CFS in primary care is required, as are trials of complex interventions. The results may help determine the usefulness of differentiating between chronic fatigue and CFS.

 

Source: Darbishire L, Ridsdale L, Seed PT. Distinguishing patients with chronic fatigue from those with chronic fatigue syndrome: a diagnostic study in UK primary care. Br J Gen Pract. 2003 Jun;53(491):441-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314617/ (Full article)

 

The radicalized self: the impact on the self of the contested nature of the diagnosis of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a relatively new disease that is difficult to diagnose. It is also a contested disease immersed in dispute about whether it is a physical or psychiatric reality. Sufferers often claim to experience not only the physical challenges of the disease, and these can be extensive, but also, initially, the anomie of suffering from a condition whose very reality is debated both in the medical and in the wider communities.

Theories of self in illness emphasize how people who are diagnosed as chronically ill work hard as they seek to maintain previous, or to develop supernormal, selves. Such goals are cast in a critical light by Foucault’s notion of the technologies of self in the context of circulating neo-liberal discourses. As people with CFS, lacking an uncontested medical diagnosis, search for meaningful self-identities, they resist previously available discourses to take up an alternative discourse, one that we call radicalized selves.

This paper raises questions about the constraints and liberties, power and powerlessness associated with a clear and undisputed medical diagnosis. It suggests a model of the self in chronic illness that considers not only changes in body and biography but also the availability of an uncontested diagnosis.

 

Source: Clarke JN, James S. The radicalized self: the impact on the self of the contested nature of the diagnosis of chronic fatigue syndrome. Soc Sci Med. 2003 Oct;57(8):1387-95. http://www.ncbi.nlm.nih.gov/pubmed/12927469

 

Medically unexplained physical symptoms, anxiety, and depression: a meta-analytic review

Abstract:

OBJECTIVE: Our objective was to review and compare, with meta-analytic methods, observational studies on the association of medically unexplained physical symptoms, anxiety, and depression with special emphasis on healthy and organically ill control groups and on different types of symptoms, measures, and illness behavior.

METHODS: A search of MEDLINE and PsycLIT/PsycINFO for abstracts from 1980 to April 2001 was performed; principal investigators in the field were contacted and article reference lists were used to retrieve additional relevant articles. Two hundred forty-four studies were included on the basis of consensus ratings if they fulfilled seven of eight inclusion criteria pertaining to diagnostic accuracy and statistical appropriateness. Five hundred twenty-two studies were deferred or excluded. We focused specifically on the four functional somatic syndromes for which there were sufficient numbers for meta-analytic integration: irritable bowel syndrome (IBS), nonulcer dyspepsia (NUD), fibromyalgia (FM), and chronic fatigue syndrome (CFS). Data were extracted independently by two authors according to a prespecified coding manual with up to 70 parameters per study.

RESULTS: Effect sizes for the association of the four functional somatic syndromes with depression and anxiety were of moderate magnitude but were highly significant statistically when compared with healthy persons and controls with medical disorders of known organic pathology. Moreover, this association was significant whether depression was measured with or without somatic items. Chronic fatigue syndrome is characterized by higher scores of depression, fibromyalgia by lower scores of anxiety than irritable bowel syndrome. Consulting behavior and severity of somatization is related to higher levels of anxiety and depression.

CONCLUSIONS: Meta-analytic integration confirms that the four functional somatic syndromes (IBS, NUD, FM, CFS) are related to (but not fully dependent on) depression and anxiety. At present, there is only limited meta-analytic evidence for the same sort of association for medically unexplained physical symptoms in general. In view of the relative independence from depression and anxiety, classification and treatment of these symptoms and syndromes as “common mental disorders” does not seem fully appropriate.

 

Source: Henningsen P, Zimmermann T, Sattel H. Medically unexplained physical symptoms, anxiety, and depression: a meta-analytic review. Psychosom Med. 2003 Jul-Aug;65(4):528-33. http://www.ncbi.nlm.nih.gov/pubmed/12883101

 

One-year outcome of unexplained fatigue syndromes in primary care: results from an international study

Abstract:

BACKGROUND: Outcome studies of chronic fatigue, neurasthenia and other unexplained fatigue syndromes are few and have been carried out in developed Western countries. This paper aimed to study the outcome of unexplained fatigue syndromes in an international primary care sample and to identify risk factors for persistence.

METHOD: We used data from the WHO collaborative study of psychological problems in general health care, in which 3201 primary care attenders from 14 countries were followed-up for 12 months. The assessment included a modified version of the Composite International Diagnostic Interview.

RESULTS: Unexplained fatigue persisted in one-fifth to one-third of the subjects depending on the definition of fatigue. From the factors studied only severity of fatigue and psychiatric morbidity at baseline were associated with persistence 12 months later. Outcome did not differ between countries of different stages of economic development.

CONCLUSIONS: The prognosis of fatigue syndromes in international primary care is relatively good. The study underlines the importance of psychological factors in influencing short-term prognosis.

 

Source: Skapinakis P, Lewis G, Mavreas V. One-year outcome of unexplained fatigue syndromes in primary care: results from an international study. Psychol Med. 2003 Jul;33(5):857-66. http://www.ncbi.nlm.nih.gov/pubmed/12877400

 

Functional status, neuropsychological functioning, and mood in chronic fatigue syndrome (CFS): relationship to psychiatric disorder

Abstract:

Individuals with chronic fatigue syndrome (CFS) face chronic physical debilitation, reduced neuropsychological functioning, and changes in emotional well-being that significantly detract from quality of life. The role of psychiatric disturbance in reducing quality of life in CFS remains unclear. In the current investigation, the role of psychiatric status in reducing health-related quality of life in CFS was examined.

Four subject groups were compared on measures of functional well-being, mood, and neuropsychological status: individuals with CFS and no history of psychiatric illness, individuals who had current symptoms of psychiatric illness that began after their CFS diagnosis, individuals who had current symptoms of psychiatric illness that began before their CFS diagnosis, and a healthy sedentary control group.

Overall, it was found that individuals with CFS suffer from profound physical impairment. Concurrent psychiatric illness, however, did not adversely affect physical functional capacity. Physical functional capacity was not worse in individuals with a concurrent psychiatric illness. As expected, concurrent psychiatric illness was found to reduce emotional well-being. Moreover, individuals with a psychiatric illness that predated the onset of CFS suffered the greatest emotional distress. Thus, an individual’s psychiatric history should be considered when attempting to understand the factors maintaining disability in CFS.

 

Source: Tiersky LA, Matheis RJ, Deluca J, Lange G, Natelson BH. Functional status, neuropsychological functioning, and mood in chronic fatigue syndrome (CFS): relationship to psychiatric disorder. J Nerv Ment Dis. 2003 May;191(5):324-31. http://www.ncbi.nlm.nih.gov/pubmed/12819552

 

Experimental evidence for interpretive but not attention biases towards somatic information in patients with chronic fatigue syndrome

Abstract:

OBJECTIVE: This study tested whether CFS patients have an attentional information processing bias for illness-related information and a tendency to interpret ambiguous information in a somatic fashion.

DESIGN: 25 patients meeting research criteria for a diagnosis of CFS were compared to 24 healthy matched controls on a modified Stroop task and an ambiguous cues task.

METHOD: In the modified Stroop task, participants colour named a series of somatic, depressed and neutral words in order to ascertain whether the somatic words were more distracting to the CFS patients than the depressed and neutral words when compared to controls. In the ambiguous cues task, participants were presented with a tape-recorded list of 30 words including 15 ambiguous illness words (e.g., vein/vain) and 15 unambiguous words. For each word, they were asked to write down the first word that came into their head. A somatic bias score was obtained for each subject by summing the number of somatic responses to the ambiguous word cues.

RESULTS: Although CFS patients were significantly slower in colour naming all of the Stroop word categories than controls, there was no evidence for illness or depressed words creating greater interference than neutral words. However, on the ambiguous cues task, CFS patients made significantly more somatic interpretations than controls and this bias was significantly associated with the extent to which they currently reported symptoms.

CONCLUSION: CFS patients have an interpretive bias for somatic information which may play a part in the maintenance of the disorder by heightening patients’ experience of physical symptoms and helping to maintain their negative illness schemas. Although patients did not show an attentional bias in this study, this may be related to the methodology employed.

 

Source: Moss-Morris R, Petrie KJ. Experimental evidence for interpretive but not attention biases towards somatic information in patients with chronic fatigue syndrome. Br J Health Psychol. 2003 May;8(Pt 2):195-208. http://www.ncbi.nlm.nih.gov/pubmed/12804333

 

Fatigue, burnout, and chronic fatigue syndrome among employees on sick leave: do attributions make the difference?

Abstract:

BACKGROUND: Persistent fatigue among employees, burnout, and chronic fatigue syndrome (CFS) are three fatigue conditions that share some characteristics in theory. However, these conditions have not been compared in empirical research, despite conceptual similarities.

METHODS: This cross sectional study aimed to investigate relations between persistent fatigue, burnout, and CFS by describing the clinical features of a sample of 151 fatigued employees on sick leave. Using validated instruments, subgroups based on research criteria for CFS and burnout within the sample of fatigued employees and a reference group of 97 diagnosed CFS patients were compared. Analyses of covariance were performed.

RESULTS: A total of 66 (43.7%) fatigued employees met research criteria for CFS (except symptom criteria) and 76 (50.3%) met research criteria for burnout. “CFS-like employees” (fatigued employees who met CFS criteria) reported stronger somatic attributions than “non-CFS-like employees”. Burnt out CFS-like employees were more depressed and distressed than CFS-like employees who were not burnt out. Burnout cases among the non-CFS-like employees had stronger psychological attributions than fatigued employees who were not burnt out. Compared to diagnosed CFS patients, CFS-like employees merely had a shorter duration of fatigue complaints. Burnt out CFS-like employees had stronger psychological attributions and were more distressed than CFS patients.

CONCLUSIONS: Fatigued employees shared many important characteristics with CFS patients, regardless of burnout status, and many fatigued employees met CFS criteria and/or burnout criteria. Differences however concerned the causal attributions that were made. This raises questions about the role of causal attributions: are they modified by fatigue complaints or do they determine illness outcome?

 

Source: Huibers MJ, Beurskens AJ, Prins JB, Kant IJ, Bazelmans E, Van Schayck CP, Knottnerus JA, Bleijenberg G. Fatigue, burnout, and chronic fatigue syndrome among employees on sick leave: do attributions make the difference? Occup Environ Med. 2003 Jun;60 Suppl 1:i26-31. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1765721/ (Full article)