Psychometric properties of the CDC Symptom Inventory for assessment of Chronic Fatigue Syndrome

Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Population Health Metrics (Impact Factor: 2.11). 08/2005; 3(1):8. DOI: 10.1186/1478-7954-3-8
Source: PubMed


Validated or standardized self-report questionnaires used in research studies and clinical evaluation of chronic fatigue syndrome (CFS) generally focus on the assessment of fatigue. There are relatively few published questionnaires that evaluate case defining and other accompanying symptoms in CFS. This paper introduces the self-report CDC CFS Symptom Inventory and analyzes its psychometric properties.
One hundred sixty-four subjects (with CFS, other fatiguing illnesses and non fatigued controls) identified from the general population of Wichita, Kansas were enrolled. Evaluation included a physical examination, a standardized psychiatric interview, three previously validated self-report questionnaires measuring fatigue and illness impact (Medical Outcomes Survey Short-Form-36 [MOS SF-36], Multidimensional Fatigue Inventory [MFI], Chalder Fatigue Scale), and the CDC CFS Symptom Inventory. Based on theoretical assumptions and statistical analyses, we developed several different Symptom Inventory scores and evaluated them on their ability to differentiate between participants with CFS and non-fatigued controls.
The Symptom Inventory had good internal consistency and excellent convergent validity. A Total score (all symptoms), Case Definition score (CFS case defining symptoms) and Short Form score (6 symptoms with minimal correlation) differentiated CFS cases from controls. Furthermore, both the Case Definition and Short Form scores distinguished people with CFS from fatigued subjects who did not meet criteria for CFS.
The Symptom Inventory appears to be a reliable and valid instrument to assess symptoms that accompany CFS. It is a positive addition to existing instruments measuring fatigue because it allows other dimensions of the illness to be assessed. Further research is needed to confirm and replicate the current findings in a normative population.

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    • "Participants' frequency and severity ratings on the SI-R were multiplied to create a composite score for each symptom at the past week, past month, and past six-month intervals, with scores ranging from 0 to 25 (Wagner et al., 2005). The authors are not aware of any previous studies on the test–retest reliability of the CDC Symptom Inventory (Wagner et al., 2005). 2.3.2. "
    12/2015; 2(1):1079945. DOI:10.1080/23311908.2015.1079945
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    • "The PEM item from the CDC CFS Symptom Inventory (Wagner et al., 2005) was used to measure PEM symptoms over the past month. Participants were asked to rate on two separate five point scales the frequency (''1 — A Little of the Time'' to ''5 — All of the Time'') and intensity (''1 — Very Mild'' to ''5 — Very Severe'') of ''Unusual fatigue following exertion that lasts for at least 24 h. "
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    ABSTRACT: Chronic Fatigue Syndrome (CFS) is characterized in part by debilitating fatigue typically exacerbated by cognitive and/or physical exertion, referred to as post-exertional malaise (PEM). In a variety of populations, the cortisol awakening response (CAR) has stood out as a marker of endocrine dysregulation relevant to the experience of fatigue, and may therefore be particularly relevant in CFS. This is the first study to examine PEM and the CAR in a sample of individuals with CFS. The CAR has also been established as a stress-sensitive measure of HPA axis functioning. It follows that better management of stress could modulate the CAR, and in turn PEM. In this cross-sectional study, we hypothesized that greater perceived stress management skills (PSMS) would relate to lower reports of PEM, via the impact of PSMS on the CAR. A total of 117 adults (72% female) with a CFS diagnosis completed self-report measures of PSMS and PEM symptomatology and a two-day protocol of saliva collection. Cortisol values from awakening and 30 minutes post-awakening were used to compute the CAR. Regression analyses revealed that greater PSMS related to greater CAR and greater CAR related to less PEM severity. Bootstrapped analyses revealed an indirect effect of PSMS on PEM via the CAR, such that greater PSMS related to less PEM, via a greater CAR. Future research should examine these trends longitudinally and whether interventions directed at improving stress management skills are accompanied by improved cortisol regulation and less PEM in individuals with CFS.
    Psychoneuroendocrinology 07/2014; 49(1). DOI:10.1016/j.psyneuen.2014.06.021 · 4.94 Impact Factor
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    • "The participants completed these validated questionnaires: (1) Centers for Disease Control (CDC) Symptom Inventory (CDC-Symp [19]); (2) McGill Pain Questionnaire – short-form (MPQ [20]); (3) Profile of Mood States (POMS [21]); (4) Fatigue Visual Analog Scale (FVAS [22]); (5) Medical Outcomes – Short Form 36 (SF-36 [23]); and (6) Multidimensional Fatigue Inventory (MFI [24]). These questionnaires were administered at several assessment points beginning with completion of all questionnaires as part of the clinical interview on the first day of testing. "
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    ABSTRACT: Background: A primary complaint of chronic fatigue syndrome (CFS) patients is post-exertion malaise, which is a worsening of symptoms following activities such as exercise. Purpose: To examine the link between gene expression for metabolite, adrenergic, immune, and glucocorticoid receptors on leukocytes and symptoms (pain, fatigue, and mood) following a maximal exercise test. Methods: Thirteen CFS patients and 11 healthy participants matched on age and fitness underwent blood draws and completed questionnaires immediately before, and 15 minutes, 48 hours, and 72 hours following, maximal exercise. Symptom and genetic measures collected before and after exercise were compared using a doubly multivariate repeated-measures analysis of variance. Results: This comparison of CFS and healthy participants resulted in a significant multivariate main effect for Group (p textless 0.05). Univariate analyses indicated group differences for adrenergic α-2A and glucocorticoid (NR3C1) receptor messenger ribonucleic acid and symptoms of fatigue and confusion. Changes in gene expression were significantly correlated with symptoms. Conclusions: Results suggest that increased glucocorticoid sensitivity may contribute to the symptoms of post-exertion malaise in CFS. As NR3C1 interacts with other transcription factors, investigating the resulting cascades may lead to greater understanding of the biological mechanism of post-exertion malaise. This finding, if confirmed, could lead to novel approaches to prevent symptom exacerbation in CFS.
    10/2013; 1(4-4):190-209. DOI:10.1080/21641846.2013.838444
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