Skip to main content

Table 1 Characteristics of patients according to post-exertional malaise severity quartiles

From: Epidemiological and clinical factors associated with post-exertional malaise severity in patients with myalgic encephalomyelitis/chronic fatigue syndrome

 Quartile 1 mild PEMaQuartile 2 moderate PEMQuartile 3 severe PEMQuartile 4 very severe PEM
Epidemiological data
 Patients, n (%)23 (11.7)74 (37.6)73 (37.1)27 (13.7)
 Females, n (%)17 (73.9)58 (78.4)50 (68.5)21 (77.8)
 Basal metabolic index, kg/m223.7 [20.2–26.3]23.3 [20.3–25.9]22.5 [19.6–25.9]21.9 [20.1–24.6]
 Age at disease onset, years28 [21–38]32 [25–41]32 [27–39]38 [31–41]
 Delay in diagnosis, months60 [25–108]62 [29.6–120]44 [21–95]26 [17–54]
Fatigue features
 Fatigue severity scale5.4 [5–6] (n = 18)5.5 [5.03–6.2] (n = 58)5.9 [5.15–6.5] (n = 59)5.9 [5.2–6.7] (n = 17)
 Fatigue scale24 [18–27.5] (n = 15)21 [18–25.5] (n = 59)25 [22–28] (n = 61)26 [22–28] (n = 21)
 MFISb physical29.5 [26.5–32] (n = 16)28 [24.3–31.8] (n = 58)31 [27–33] (n = 59)30 [26.5–33] (n = 22)
 MFIS cognitive24 [19–34] (n = 16)26 [19.2–30] (n = 58)31 [24.5–33.5] (n = 59)26 [22.3–30.6] (n = 22)
 MFIS psychosocial6 [5–7] (n = 16)5 [4–6] (n = 58)6 [5–8] (n = 59)6 [5–7] (n = 22)
Symptom clustersc, n (%)
Neurological impairments23 (100)74 (100)73 (100)27 (100)
 Neurocognitive impairments23 (100)74 (100)73 (100)27(100)
  Difficulty processing information23 (100)68 (91.9)70 (95.9)27 (100)
  Short-term memory loss16 (69.6)62 (83.8)66 (90.4)24 (88.9)
 Pain22 (95.7)72 (97.3)71 (97.3)26 (96.3)
  Headaches16 (69.6)53 (71.6)56 (76.7)21 (77.8)
  Significant pain19 (82.6)64 (86.5)68 (93.2)26 (96.3)
 Sleep disturbances22 (95.7)74 (100)72 (98.6)27 (100)
  Disturbed sleep patterns21 (91.3)65 (87.8)64 (87.7)22 (81.5)
  Unrefreshed sleep21 (91.3)74 (100)69 (94.5)25 (92.6)
 Neurosensory, perceptual and motor disturbances22 (95.7)73 (100)73 (100)27 (100)
  Neurosensory and perceptual troubles20 (87)62 (83.8)69 (94.5)23 (85.2)
  Motor disturbances20 (87)69 (93.2)69 (94.5)27 (100)
 Immune, gastrointestinal, and genitourinary impairments21 (91.3)66 (89.2)71 (97.3)24 (88.9)
  Flu-like symptoms16 (69.6)50 (67.6)59 (80.8)19 (70.4)
  Susceptibility to viral infections3 (13)26 (35.1)31 (42.5)12 (44.4)
  Gastrointestinal impairments17 (73.9)63 (85.1)60 (82.2)22 (81.5)
  Genitourinary impairments2 (8.7)28 (37.8)29 (39.7)7 (25.9)
  Sensitivities to food, medications, odors, or chemicals2 (8.7)6 (8.1)4 (5.5)35 (11.1)
 Energy production/transportation impairments22 (95.7)74 (100)72 (98.6)27 (100)
  Cardiovascular manifestations19 (82.6)72 (97.3)65 (89)27 (100)
  Respiratory manifestations9 (39.1)36 (48.6)38 (52.1)19 (70.4)
  Loss of thermostatic instability18 (78.3)65 (87.8)61 (83.6)26 (96.3)
  Intolerance of extremes of temperatures13 (56.5)61 (82.4)42 (57.5)21 (77.8)
  1. Categorical data were expressed as absolute number and percentage
  2. Continuous data were expressed as median and quartiles
  3. a Post-exertional malaise
  4. bModified fatigue impact scale
  5. CME International Consensus Criteria [3]