Table 3 Participant characteristics per cluster

Sex, n (%)

 Male

6 (25.0)

2 (8.7)

8 (26.7)

4 (15.4)

6 (35.3)

8 (42.1)

4 (9.3)

3 (16.7)

2 (5.3)¹

3 (20.0)

1 (10.0)

6 (33.3)

2 (10.0)

 Female

18 (75.0)

21 (91.3)

22 (73.3)

22 (84.6)

11 (64.7)

10 (52.6)

39 (90.7)

15 (83.3)

36 (94.7)

12 (80.0)

9 (90.0)

12 (66.7)

17 (85.0)

 Other/I don’t want to say

–

–

–

–

–

1 (5.3)

–

–

–

–

–

–

1 (5.0)

Age, years

52 (47–61)

38 (27–48)²

55 (45–58)

55 (39–60)

51 (39–62)

60 (50–70)

59 (51–64)

52 (44–61)

57 (39–63)

52 (43–59)

52 (41–58)

61 (53–71)

62 (52–70)

BMI, kg/m²

24.6 (21.4–29.0)

20.9 (20.3–27.6)

26.0 (21.7–30.7)

23.4 (21.9–26.5)

24.0 (19.6–26.2)

25.9 (21.5–31.2)

24.5 (22.3–28.6)

23.5 (21.2–26.1)

24.2 (21.4–29.6)

21.3 (20.3–25.3)

22.7 (21.0–27.9)

25.4 (22.8–26.8)

22.4 (19.8–28.1)

Ethnicity, n (%)

 Black, African-American

1 (4.2)

–

–

–

–

–

–

–

–

–

–

–

–

 White

22 (91.7)

23 (100.0)

29 (96.7)

24 (92.3)

17 (100.0)

18 (94.7)

43 (100.0)

17 (94.4)

37 (97.4)

15 (100.0)

9 (90.0)

18 (100.0)

19 (95.0)

 American Indian/Alaska Native

–

–

–

–

–

–

–

–

–

–

–

–

–

 Asian or Pacific Islander

1 (4.2)

–

–

–

–

–

–

–

–

–

1 (10.0)

–

–

 Other

–

–

1 (3.3)

2 (7.7)

–

1 (5.3)

–

1 (5.6)

1 (2.6)

–

–

–

1 (5.0)

Marital status, n (%)

 Married or living with partner

15 (62.5)

9 (39.1)

16 (53.3)

13 (50.0)

8 (47.1)

8 (42.1)

27 (62.8)

13 (72.2)

22 (57.9)

12 (80.0)

2 (20.0)

8 (44.4)

13 (65.0)

 Living alone

8 (33.3)

12 (52.2)

10 (33.3)

11 (42.3)

8 (47.1)

7 (36.8)

14 (32.6)

5 (27.8)

15 (39.5)

3 (20.0)

6 (60.0)

8 (44.4)

6 (30.0)

 Widow(er)/divorced

1 (4.2)

2 (8.7)

4 (13.3)

2 (7.7)

1 (5.9)

4 (21.1)

2 (4.7)

–

1 (2.6)

–

2 (20.0)

2 (11.1)

1 (5.0)

Children, n (%)

 No

12 (50.0)

16 (69.6)

16 (53.3)

15 (57.7)

9 (52.9)

9 (47.4)

24 (55.8)

9 (50.0)

22 (57.9)

8 (53.3)

4 (40.0)

7 (38.9)

9 (45.0)

 Yes

12 (50.0)

7 (30.4)

14 (46.7)

11 (42.3)

8 (47.1)

10 (52.6)

19 (44.2)

9 (50.0)

16 (42.1)

7 (46.7)

6 (60.0)

11 (61.1)

11 (55.0)

Education level, n (%)^a

 Low

1 (4.2)

–

–

–

–

2 (10.5)

1 (2.3)

3 (16.7)

1 (2.6)

–

1 (10.0)

1 (5.6)

–

 Medium

7 (29.2)

8 (34.8)

13 (43.3)

9 (34.6)

6 (35.3)

10 (52.6)

19 (44.2)

6 (33.3)

10 (26.3)

7 (46.7)

5 (50.0)

1 (5.6)

7 (35.0)

 High

16 (66.7)

14 (60.9)

17 (56.7)

16 (61.5)

11 (64.7)

7 (36.8)

23 (53.5)

9 (50.0)

27 (71.1)

8 (53.3)

4 (40.0)

15 (83.3)

13 (65.0)

 Other/I don’t want to say

–

1 (4.3)

–

1 (3.8)

–

–

–

–

–

–

–

1 (5.6)

–

Current work status, n (%)^b

 On disability

16 (66.7)

19 (82.6)

25 (83.3)

18 (69.2)

12 (70.6)

7 (36.8)

31 (72.1)

14 (77.8)

18 (47.4)

8 (53.3)

10 (100.0)

4 (22.2)³

10 (50.0)

 Student

–

2 (8.7)

–

–

–

–

–

1 (5.6)

–

1 (6.7)

–

1 (5.6)

–

 Homemaker

3 (12.5)

1 (4.3)

1 (3.3)

1 (3.8)

2 (11.8)

1 (5.3)

9 (20.9)

1 (5.6)

1 (2.6)

2 (13.3)

–

–

3 (15.0)

 Retired

1 (4.2)

–

1 (3.3)

3 (11.5)

2 (11.8)

8 (42.1)⁴

7 (16.3)

2 (11.1)

6 (15.8)

3 (20.0)

1 (10.0)

8 (44.4)⁴

7 (35.0)

 Unemployed

3 (12.5)

1 (4.3)

–

–

2 (11.8)

1 (5.3)

3 (7.0)

1 (5.6)

4 (10.5)

1 (6.7)

–

1 (5.6)

2 (10)

 Working part-time

10 (41.7)⁵

2 (8.7)

–⁵

4 (15.4)

3 (17.6)

2 (10.5)

5 (11.6)

1 (5.6)

11 (28.9)

2 (13.3)

1 (10.0)

5 (27.8)

6 (30.0)

 Working full-time

1 (4.2)

–

3 (10.0)

–

–

2 (10.5)

–

–

2 (5.3)

–

–

1 (5.6)

-

Case definition, n (%)

 Fukuda Criteria

20 (83.3)

21 (91.3)

26 (86.7)

26 (100.0)

17 (100.0)

16 (84.2)

39 (90.7)

15 (83.3)

34 (89.5)

14 (93.3)

5 (50.0)⁶

17 (94.4)

20 (100.0)

 Canadian Clinical ME/CFS Criteria

12 (50.0)

15 (65.2)

26 (86.7)

26 (100.0)

9 (52.9)

3 (15.8)⁷

35 (81.4)

13 (72.2)

6 (15.8)⁷

11 (73.3)

5 (50.0)

–⁷

9 (45.0)

 International Consensus Criteria

3 (12.5)

6 (26.1)

14 (46.7)

21 (80.8)⁸

6 (35.3)

3 (15.8)

19 (44.2)

18 (100.0)⁹

1 (2.6)

6 (40.0)

10 (100.0)⁸

–

8 (40.0)

 Institute of Medicine

19 (79.2)

21 (91.3)

26 (86.7)

26 (100.0)

17 (100.0)

12 (63.2)

39 (90.7)

15 (83.3)

26 (68.4)

14 (93.3)

5 (50.0)

4 (22.2)¹⁰

16 (80.0)

Nr. of case definition, n (%)

 0

3 (12.5)

2 (8.7)

2 (6.7)

–

–

2 (10.5)

1 (2.3)

–

3 (7.9)

–

–

1 (5.6)

–

 1

1 (4.2)

–

2 (6.7)

–

–

5 (26.3)

3 (7.0)

3 (16.7)

9 (23.7)

1 (6.7)

5 (50.0)

13 (72.2)¹¹

2 (10.0)

 2

9 (37.5)

2 (8.7)

–

–

6 (35.3)

7 (36.8)

4 (9.3)

–

20 (52.6)¹²

2 (13.3)

–

4 (22.2)

7 (35.0)

 3

9 (37.5)

11 (47.8)

14 (46.7)

5 (19.2)

7 (41.2)

5 (26.3)

19 (44.2)

2 (11.1)

6 (15.8)

8 (53.3)

–¹³

–

7 (35.0)

 4

2 (8.3)

5 (21.7)

12 (40.0)

21 (80.8)¹⁴

4 (23.5)

–

16 (37.2)

13 (72.2)¹⁰

–

4 (26.7)

5 (50.0)

–

4 (20.0)

Number or reported symptoms, median (IQR)^c

22 (19–27)¹⁵

28 (23–31)¹⁶

38 (34–43)

41 (36–44)

23 (21–26)¹⁵

17 (14–22)¹⁵

31 (27–34)¹⁶

45 (41–53)

15 (11–19)¹⁷

28 (25–32)¹⁶

61 (59–62)

8 (4–11)¹⁸

21 (17–26)¹⁵