Table 1 Study and population characteristics of included studies

Protocol only, n (%)

 Yes

5 (38.5)

14 (23.0)

19 (25.7)

 No

8 (61.5)

47 (77.0)

55 (74.3)

Funding, n (%)

 Yes

9 (69.2)

45 (73.8)

54 (73.0)

 No

1 (7.7)

9 (14.8)

10 (13.5)

 Not given

3 (23.1)

7 (11.5)

10 (13.5)

Country, n (%)

 Australia

0 (0.0)

8 (13.1)

8 (10.8)

 Brazil

0 (0.0)

2 (3.3)

2 (2.7)

 Canada

0 (0.0)

7 (11.5)

7 (9.5)

 China

2 (15.4)

8 (13.1)

10 (13.5)

 Colombia

0 (0.0)

1 (1.6)

1 (1.4)

 Finland

0 (0.0)

2 (3.3)

2 (2.7)

 France

1 (7.7)

3 (4.9)

4 (5.4)

 Germany

0 (0.0)

3 (4.9)

3 (4.1)

 Italy

0 (0.0)

2 (3.3)

2 (2.7)

 Korea

0 (0.0)

1 (1.6)

1 (1.4)

 Netherlands

8 (61.5)

1 (1.6)

9 (12.2)

 Norway

1 (7.7)

1 (1.6)

2 (2.7)

 Portugal

0 (0.0)

1 (1.6)

1 (1.4)

 Sweden

0 (0.0)

1 (1.6)

1 (1.4)

 UK

0 (0.0)

6 (9.8)

6 (8.1)

 USA

1 (7.7)

14 (23.0)

15 (20.3)

Health/disease area, n (%)

 Cancer

0 (0.0)

2 (3.3)

2 (2.7)

 Cardiovascular

0 (0.0)

6 (9.8)

6 (8.1)

 Chronic pain

0 (0.0)

4 (6.6)

4 (5.4)

 Diabetes

1 (7.7)

0 (0.0)

1 (1.4)

 Gastrointestinal

0 (0.0)

4 (6.6)

4 (5.4)

 Genetic neurodevelopmental

1 (7.7)

1 (1.6)

2 (2.7)

 Genitourinary

1 (7.7)

1 (1.6)

2 (2.7)

 Headache

0 (0.0)

1 (1.6)

1 (1.4)

 High cholesterol

0 (0.0)

1 (1.6)

1 (1.4)

 Hyperkalaemic periodic paralysis

1 (7.7)

0 (0.0)

1 (1.4)

 Musculoskeletal

1 (7.7)

2 (3.3)

3 (4.1)

 Neurological

4 (30.8)

12 (19.7)

16 (21.6)

 Neuropsychiatric

1 (7.7)

2 (3.3)

3 (4.1)

 Non-specific

0 (0.0)

6 (9.8)

6 (8.1)

 Physical activity

0 (0.0)

5 (8.2)

5 (6.8)

 Prosthetics

0 (0.0)

1 (1.6)

1 (1.4)

 Psychiatric

0 (0.0)

3 (4.9)

3 (4.1)

 Pulmonary/respiratory

1 (7.7)

7 (11.5)

8 (10.8)

 Renal

2 (15.4)

2 (3.3)

4 (5.4)

 Thyroid disorder

0 (0.0)

1 (1.6)

1 (1.4)

Number of participants randomised, median (Q1, Q3)

6 (4, 9)

10 (3, 20)

9 (4, 20)

Number of participants completing, median (Q1, Q3)

5 (3, 6)

8 (3, 15)

7 (3, 14)

Age group of included participants, n (%)

 Children only (< 18 years)

0 (0.0)

8 (13.1)

8 (10.8)

 Adults only

9 (69.2)

51 (83.6)

60 (81.1)

 Children and adults

2 (15.4)

2 (3.3)

4 (5.4)

 Not reported

2 (15.4)

0 (0.0)

2 (2.7)

Target sample size (protocols only), median (Q1, Q3)

6 (5, 18)

40 (20, 47)

20 (10, 43)