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Table 1 Characteristics of clinically evaluated subjects

From: An evaluation of exclusionary medical/psychiatric conditions in the definition of chronic fatigue syndrome

Characteristics    Exclusionary Condition Odds ratio (OR)*
  All Yes No Unadjusted Ors Adjusted Ors
  n = 781 n = 280 (36%) n = 501 (64%) (95% CI) (95% CI)
Part A
Classification
        
   CFS-like 291 (37.26) 141 (48.45) 150 (51.55) 3.25 (2.03-4.80) 1.50 (0.79-2.87)
   Unwell 267 (34.19) 89 (34.19) 178 (66.67) 1.73 (1.15-2.59) 0.89 (0.53-1.52)
   Well 223 (28.55) 50 (22.42) 173 (77.58) 1.00 1.00
Age (years), mean (SD) 43.50 (10.36) 43.10 (10.39) 43.73 (10.35) 0.94 (0.81-1.09) 0.83 (0.70-1.00)
Sex         
   Male 186 (23.82) 71 (38.17) 115 (61.83) 1.14 (0.81-1.60) 1.44 (0.96-2.16)
   Female 595 (76.18) 209 (35.13) 386 (64.87) 1.00 1.00
Race         
   Black 195 (24.97) 91 (46.67) 104 (53.33) 1.86 (1.34-2.60) 1.89 (1.24-2.88)
   Other 35 (4.48) 13 (37.14) 22 (62.86) 1.26 (0.62-2.56) 1.12 (0.51-2.45)
   White 551 (70.55) 176 (31.94) 375 (68.06) 1.00 1.00
Residential areas         
   Rural 383 (49.04) 144 (37.60) 239 (62.40) 1.81 (1.16-2.82) 2.02 (1.20-3.39)
   Urban 266 (34.06) 103 (38.72) 163 (61.18) 1.90 (1.19-3.02) 1.96 (1.16-3.29)
   Metropolitan 132 (16.90) 33 (25.00) 99 (75.00) 1.00 1.00
BMI (kg/m2), mean (SD) 28.08 (5.34) 28.76 (5.52) 27.70 (5.20) 1.22 (1.05-1.41) 1.02 (0.86-1.22)
Part B
MFI
       Per SD increment Per SD increment
   General fatigue 12.90 (4.69) 14.10 (4.36) 12.22 (4.74) 1.52 (1.30-1.78) 1.23 (0.87-1.74)
   Physical fatigue 10.86 (4.37) 12.05 (4.32) 10.20 (4.25) 1.54 (1.32-1.79) 1.06 (0.78-1.44)
   Reduced activity 9.24 (4.16) 10.13 (4.33) 8.75 (3.98) 1.39 (1.20-1.61) 0.93 (0.72-1.19)
   Reduced motivation 9.58 (3.90) 10.60 (4.12) 9.01 (3.66) 1.51 (1.30-1.76) 1.21 (0.92-1.59)
   Mental fatigue 10.94 (4.54) 12.09 (4.50) 10.29 (4.43) 1.50 (1.29-1.74) 1.12 (0.89-1.40)
SF-36        Per SD increment Per SD increment
   Physical Functioning 75.64 (24.03) 67.57 (26.41) 80.11 (21.35) 1.68 (1.44-1.95) 0.62 (0.34-1.10)
   Role physical 41.41 (41.60) 27.14 (37.45) 49.50 (41.68) 1.78 (1.52-2.09) 0.70 (0.50-0.99)
   Bodily pain 60.61 (26.63) 52.35 (26.93) 65.23 (25.34) 1.65 (1.41-1.92) 0.66 (0.41-1.07)
   Social functioning 71.32 (27.78) 62.28 (29.17) 76.37 (25.65) 1.67 (1.43-1.94) 1.08 (0.70-1.68)
   Mental health 68.50 (22.23) 62.29 (23.05) 71.98 (20.99) 1.55 (1.33-1.80) 1.11 (0.63-1.94)
   Role emotional 49.12 (43.31) 37.74 (41.49) 55.49 (43.05) 1.52 (1.31-1.77) 1.08 (0.78-1.50)
   Vitality 47.77 (28.01) 41.39 (27.03) 51.38 (27.94) 1.44 (1.24-1.67) 1.61 (1.02-2.53)
   General health 61.87 (23.57) 55.24 (23.88) 65.58 (22.58) 1.56 (1.34-1.82) 0.98 (0.64-1.52)
   PCS 46.28 (10.72) 43.07 (11.64) 48.08 (9.72) 1.60 (1.38-1.86) 1.50 (0.40-5.68)
   MCS 44.67 (12.79) 41.27 (13.63) 46.58 (11.89) 1.52 (1.31-1.76) 0.68 (0.22-2.07)
   HUI2† 76.14 (14.61) 70.75 (14.80) 79.16 (13.61) 1.82 (1.56-2.13) Not included§
SI        Per SD increment Per SD increment
   SI_CFS 23.13 (20.58) 28.13 (21.45) 20.34 (19.56) 1.45 (1.25-1.68) 0.78 (0.56-1.08)
   SI_NCFS 19.89 (18.09) 24.44 (20.21) 17.34 (16.26) 1.48 (1.27-1.71) 1.04 (0.79-1.37)
  1. *Adjusted ORs were obtained for the multiple logistic regression models including all variables in the entire table; ORs with P-values < 0.05 are in bold font.
  2. Nichole's Health Utility Index 2 (HUI2) was included in the multivariate model because it is a linear combination of eight of the Medical Outcomes Survey Short Form-36 (SF-36) subscales and strongly correlated with physical component summary (PCS) and mental component summary (MCS).
  3. CFS = chronic fatigue syndrome; CI = confidence interval; SD = standard deviation; BMI = body mass index; MFI = multidimensional fatigue inventory; SI_CFS = symptom inventory summary score of 8 CFS symptoms; SI_NCFS = symptom inventory summary score of non-CFS symptoms