Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms

Table 3 Empirical case definition for chronic fatigue (syndrome)[47]

Fatigue:

A score

≥ 13 (out of 20) on the general fatigue or

≥ 10 (out of 20) on the reduced activity

subscales of the multidimensional fatigue inventory[56]

Functional impairment:

A score

≤ 70 (out of 100) on the physical function, or

≤ 50 (out of 100) on role physical, or

≤ 75 (out of 100) on the social function, or

≤ 66.7 (out of 100) on the role emotional

subscales of the medical outcomes survey short form-36 (SF-36)[11]

Secondary symptoms:

≥ 4 of the following 8 symptoms:

Impaired memory or concentration

Unrefreshing sleep

Headaches

Muscle pain

Joint pain

Sore throat

Tender cervical nodes and

Unusual post exertional fatigue

And A score of ≥ 25 (out of 128)

On the Symptom Inventory Case Definition subscale[57]