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Table 1 Study characteristics

From: Systematic review of randomized controlled trials for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)

Items Adults Adolescents Total
N. of RCT (%) 51 (91.1) 5 (8.9) 56 (100.0)
N. of participants (%) (males/females) 6,499 (93.4) (1611/4888) 457 (6.6) (102/355) 6956 (100.0) (1713/5243)
Mean N. of participants 127.4 ± 113.3 91.4 ± 33.5 124.2 ± 109.0
Mean age (year)a 40.2 ± 4.0 15.5 ± 0.3 38.7 ± 8.1
N. of case definitions for inclusion criteria (%)b,c
 CDC 1994 (Fukuda) 37 (72.5) 5 (100.0) 42 (75.0)
 Schluederberg 1992 2 (3.9) 2 (3.6)
 Oxford 1991 (Sharpe) 12 (23.5) 1 (20.0) 13 (23.2)
 CDC 1988 (Holmes) 3 (5.9) 3 (5.4)
 Lloyd 1988 2 (3.9) 2 (3.6)
 Others 5 (9.8) 1 (20.0) 6 (10.7)
RCTs with pharmacological intervention (N, %) 23 (92.0) 2 (8.0) 25 (100.0)
 Kinds of interventions (%) 20 (90.9) 2 (9.1) 22 (100.0)
 Mean treatment period (weeks) 11.0 ± 7.0 8.5 ± 0.7 10.8 ± 6.8
RCTs with non-pharmacological intervention (N, %) 26 (89.7) 3 (10.3) 29 (100.0)
 Kinds of interventionsd 18 (94.7) 2 (10.5) 19 (100.0)
 Mean treatment period (weeks) 17.1 ± 7.1 30.7 ± 15.1 18.5 ± 8.9
RCTs with combined interventions (N, %) 2 (100.0) 2 (100.0)
 Kinds of interventions (%) 4 (100.0) 4 (100.0)
 Mean treatment period (weeks) 26 ± 2.8 26 ± 2.8
Primary measurements in 55 RCTs (n, %)c,e
 Checklist Individual Strength (CIS) 20 (35.7)
 36-item Short Form health survey (SF-36) 18 (32.1)
 Sickness Impact Profile (SIP) 8 (14.3)
 Chalder Fatigue Scale 8 (14.3)
 Visual Analogue Scale (VAS) 6 (10.7)
 Clinical Global Impression (CGI) 5 (8.9)
 Karnofsky Performance Scale (KPS) 3 (5.4)
 School attendance rate (SAR) 3 (5.4)
 Multidimensional Fatigue Inventory (MFI) 2 (3.6)
 Fatigue Severity Scale (FSS) 2 (3.6)
 Others 21 (37.5)
  1. aThis is the mean of ages presented as median or mean in original articles
  2. bTwelve RCTs used two case definitions for inclusion criteria
  3. cSome items have been applied multiple times, thus the total percentage is larger than 100%
  4. dOne intervention (CBT) was used for both of adult and adolescent studies
  5. eTwenty-nine RCTs used multiple primary measurements