Is Fatigue a Disease-Specific or Generic Symptom in Chronic Medical Conditions?

• Published in: Health psychology 2018-06, Vol.37 (6), p.530-543
• Main Authors: Menting, Juliane, Tack, Cees J., Bleijenberg, Gijs, Donders, Rogier, Droogleever Fortuyn, Hal A., Fransen, Jaap, Goedendorp, Martine M., Kalkman, Joke S., Strik-Albers, Riet, van Alfen, Nens, van der Werf, Sieberen P., Voermans, Nicol C., van Engelen, Baziel G., Knoop, Hans
• Format: Article
• Language: English
• Subjects: Chronic Disease - psychology; Chronic Illness; Chronic illnesses; Chronic pain; Cross-Sectional Studies; Fatigue; Fatigue - psychology; Female; Functional impairment; Human; Humans; Interaction terms; Male; Medical conditions; Middle Aged; Physical ability; Psychosocial factors; Regression analysis; Self-efficacy; Severity; Severity (Disorders); Sleep disorders; Symptoms; Test Construction
• ISSN: 0278-6133; 1930-7810
• DOI: 10.1037/hea0000598

Objective: Severe fatigue is highly prevalent in various chronic diseases. Disease-specific fatigue models have been developed, but it is possible that fatigue-related factors in these models are similar across diseases. The purpose of the current study was to determine the amount of variance in fatigue severity explained by: (a) the specific disease, (b) factors associated with fatigue across different chronic diseases (transdiagnostic factors), and (c) the interactions between these factors and specific diseases. Method: Data from 15 studies that included 1696 patients with common chronic diseases and disorders that cause long-term disabilities were analyzed. Linear regression analysis with the generalized least-squares technique was used to determine fatigue-related factors associated with fatigue severity, that is, demographic variables, health-related symptoms and psychosocial variables. Results: Type of chronic disease explained 11% of the variance noted in fatigue severity. The explained variance increased to 55% when the transdiagnostic factors were added to the model. These factors were female sex, age, motivational and concentration problems, pain, sleep disturbances, physical functioning, reduced activity and lower self-efficacy concerning fatigue. The predicted variance increased to 61% when interaction terms were added. Analysis of the interactions revealed that the relationship between fatigue severity and relevant predictors mainly differed in strength, not in direction. Conclusions: Fatigue severity can largely be explained by transdiagnostic factors; the associations vary between chronic diseases in strength and significance. This suggests that severely fatigued patients with different chronic diseases can probably benefit from a transdiagnostic fatigue-approach which focuses on individual patient needs rather than a specific disease.