Importance of fatigue and its measurement in chronic liver disease

Table 1 Summary of recently published reviews specifically on fatigue in liver disease

Article title
Fatigue in chronic liver disease: New insights and therapeutic approaches[3]
Fatigue complicating chronic liver disease[95]
Depression, fatigue and neurocognitive deficits in chronic hepatitis C[96]
Patient-Reported outcomes and fatigue in patients with chronic hepatitis C infection[21]
Future directions for investigation of fatigue in chronic hepatitis C viral infection[97]
Fatigue, depression and chronic hepatitis C infection[98]
Fatigue in cholestatic liver disease-a perplexing symptom[99]
Fatigue in liver disease: Pathophysiology and clinical management[11]
Understanding and treating fatigue in primary biliary cirrhosis (cholangitis) and primary sclerosing cholangitis[19]
Liver-brain interactions in inflammatory liver diseases: implications for fatigue and mood disorders[30]
Fatigue in primary biliary cirrhosis (cholangitis)[100]
Complications, symptoms, quality of life and pregnancy in cholestatic liver disease[101]
Fatigue in primary biliary cirrhosis (cholangitis)[102]

Table 2 Commonly used measures of fatigue

	Type of assessment	Domain(s) assessed	Length	Used in liver disease?
Fatigue assessment scale[103]	5-point Likert scale	Severity	10 items	Rarely
Fatigue severity scale[104]	7-point Likert scale	Severity, Impact	9 items	Often
Fatigue impact scale[105]	5-point Likert scale	Physical, Cognitive, Psychosocial	40 items	Sometimes
Fatigue scale[106]	4-point Likert scale	Physical, Mental	11 items	Rarely
Multidimensional Assessment of Fatigue[107]	Visual analog scale	Severity, Distress, Impact on Activities	14 items	Rarely
Multidimensional fatigue inventory[108]	5-point Likert scale	General, Physical, Activity, Motivation, Mental	20 items	Sometimes
Visual analog fatigue scale[109]	Visual analog scale	Energy, Fatigue	18 items	Rarely
Functional assessment of chronic illness therapy fatigue scale[110]	5-point Likert scale	Severity, Impact	13 items	Often
Sf-36 vitality scale[111]	5-point Likert scale	Energy	4 items	Often
Chronic liver disease questionnaire fatigue scale[112]	7-point Likert scale	Energy	5 items	Often
PROMIS®-fatigue[113]	5-point Likert scale	Severity	Variable1	Rarely

¹PROMIS® is a computer adaptive test where the specific questions and number of questions is tailored to the individual using item response theory techniques. Usually the number of items will range between 4-12.

Table 3 Fatigue symptoms for diagnosing pathological fatigue

The symptoms must have been present every (or nearly every) day over a 2-wk period during the past month
Necessary	Significant fatigue
	Diminished energy
	Increased need to rest disproportionate to level of activity
At least five of these symptoms must be present	Experience of limb heaviness of generalized weakness
	Diminished concentration or attention
	Decreased motivation or interest to engage in usual activities
	Insomnia or hypersomnia
	Experience sleep as unrefreshing or non-restorative
	Perceived need to struggle to overcome inactivity
	Marked emotional reactivity to feeling fatigued
	Perceived problems with short term memory
	Post-exertional malaise for several hours

Table 4 Established associations among physical findings, diagnoses and fatigue

Adrenal insufficiency
Anemia
Auto-immune diseases
Cancer	Especially in breast, pancreatic, pulmonary
Cardiac failure
Deconditioning
Electrolyte imbalance
Hypo/hyperthyroidism
Infection
Malnutrition
Medication	Anti-emetics, anti-histamines, anxiolytics, chemotherapy, opioids, radiation, sedatives
Pulmonary	Chronic obstructive pulmonary disease, cystic fibrosis
Renal failure
Sarcopenia
Stress	Physiological, hypercortisolism
Symptoms Contributing	Depressive symptoms, insomnia, pain
Syndromes of unknown etiology	Lyme disease, chronic fatigue syndrome
Vitamin deficiency	Especially B complex