Table 2.
Prevalence of CFS/ME by subgroup (± SD)
| Groupa | Male (%) | Female (%) | Total (%, M/F) | Total (%) |
|---|---|---|---|---|
| (21 studies/24 data) | (46 studies/56 data) | |||
| Average prevalence of all studies | 1.11 ± 1.05 | 2.24 ± 2.59 | 1.67 ± 2.06 | 1.40 ± 1.57 |
| Pooled prevalence of all studies (Total N. of CFS/N. of participantsb) | 0.74 (451/61,069) | 1.92 (1308/68,124) | 1.37 (1778/129,780) | 0.39 (5370/1387,787) |
| Pooled prevalence of the general population (N. of adult CFS/N. of adult participants) | 0.75 (451/60,432) | 1.92 (1304/67,790) | 1.38 (1774/128,809) | 0.38 (4724/1258,337) |
| Mean age of CFS patients (12 studies) | 39.3 ± 7.8 | 39.1 ± 7.6 | 40.4 ± 7.7 | 40.4 ± 7.7 |
| Prevalence by subgroup (N. of studies that reported sex) | ||||
| Study participants | ||||
| Community (16) | 1.03 ± 1.13 | 2.31 ± 2.88 | 1.67 ± 2.28 | 1.56 ± 1.80 |
| Pooled prevalence (N. of CFS/N. of participantsb) | 0.70 (404/57,751) | 1.94 (1190/61,365) | 1.34 (1594/119,116) | 0.73 (4014/548,461) |
| Primary care (5) | 1.39 ± 0.56 | 1.96 ± 0.74 | 1.68 ± 0.72 | 1.16 ± 1.13 |
| Pooled prevalence (N. of CFS/N. of participantsb) | 1.42 (47/3318) | 1.75 (118/6759) | 1.64 (165/10,077) | 0.21 (1739/839,326) |
| Publication year | ||||
| 1990–2000 (9) | 0.62 ± 0.58 | 1.26 ± 1.42 | 0.94 ± 1.13 | 0.96 ± 0.91 |
| 2001–2010 (10) | 1.35 ± 1.18 | 2.99 ± 3.11 | 2.17 ± 2.49 | 2.08 ± 2.01 |
| 2011–2018 (2) | 1.75 ± 0.83 | 1.78 ± 0.71 | 1.76 ± 0.77 | 0.84 ± 0.86 |
| Population group | ||||
| General population (≥ 18 years) (19) | 1.39 ± 1.05 | 2.83 ± 2.61 | 2.11 ± 2.07 | 1.45 ± 1.68 |
| Children/adolescents (< 18 years) (0) | – | – | – | 0.89 ± 0.82 |
| Specific populationc(1) | 0.12 | 0.06 | 0.09 ± 0.03 | 1.62 ± 1.17 |
| Case definition (8 case definitions) | ||||
| CDC-1994 [22] (16) | 1.24 ± 1.04 | 2.61 ± 2.75 | 1.93 ± 2.19 | 1.46 ± 1.34 |
| Holmes [23] (4) | 0.07 ± 0.05 | 0.14 ± 0.15 | 0.11 ± 0.12 | 0.34 ± 0.40 |
| Australian [25] (1) | 2.65 | 5.23 | 3.94 ± 1.29 | 2.52 ± 2.99 |
| Oxford [24] (2) | 1.23 ± 0.64 | 1.76 ± 1.22 | 1.51 ± 1.00 | 1.73 ± 1.35 |
| CCC [27] ECD [26] PVES [28] NICE [29]d(0) | – | – | – | 0.53 ± 0.77 |
| Country (13 countries) | ||||
| Western (12) | 1.14 ± 0.97 | 2.40 ± 2.86 | 1.77 ± 2.22 | 1.32 ± 1.45 |
| Asian (8) | 1.23 ± 2.92 | 2.06 ± 1.85 | 1.65 ± 1.64 | 1.51 ± 1.74 |
| Otherse(1) | 0.11 | 0.50 | 0.31 ± 0.20 | 2.65 ± 2.37 |
| Diagnostic method | ||||
| Interview (medical test -) (9) | 1.70 ± 1.21 | 4.32 ± 3.24 | 3.01 ± 2.63 | 2.03 ± 2.13 |
| Interview (medical test +) (10) | 0.86 ± 0.70 | 1.23 ± 0.93 | 1.05 ± 0.84 | 1.17 ± 0.77 |
| Physician diagnosis (0) | – | – | – | 0.10 ± 0.05 |
| Medical records (1) | 2.57 | 2.49 | 2.53 ± 0.06 | 1.25 ± 1.00 |
aThe prevalence by sex was estimated from studies that reported both the number of participants and the number with CFS
bParticipant number was applied to individual prevalence data for the studies with multiple case definitions
cSpecific groups included nurses, Gulf War veterans, livestock workers, company employees, etc
dCCC, Canadian Consensus Criteria; ECD, epidemiological case definition; PVES, post viral exhaustion syndrome; and NICE, National Institute for Health and Care Excellence guideline 2007; two studies with no verification of case definition and defined criteria were excluded
eOther countries included India and Nigeria