Table 2 Methodological data for comparative studies included in the final analysis

DESIGN

Trial design, n (%)

Parallel groups

21 (65.6)

19 (76.0)

2 (28.6)

Cross-over

2 (6.3)

1 (4.0)

1 (14.3)

Randomized placebo phase

2 (6.3)

2 (8.0)

0

Within-person

1 (3.1)

1 (4.0)

0

Delayed-start design

2 (6.3)

2 (8.0)

0

Observational run-in period

1 (3.1)

0

1 (14.3)

Challenge–dechallenge–rechallenge

1 (3.1)

0

1 (14.3)

Use of a historical control group

2 (6.3)

0

2 (28.6)

Studies reported design justifications, n (%)*

Yes

6 (18.8)

4 (16.0)

2 (28.6)

No

26 (81.3)

21 (84.0)

5 (71.4)

Blinding, n (%)

Participants only

2 (6.3)

2 (8.0)

0

Participants and care provider

4 (12.5)

4 (16.0)

0

Participants, care provider and outcome assessor

3 (9.4)

3 (12.0)

0

Outcome assessor only

4 (12.5)

4 (16.0)

0

Participants and outcome assessor

1 (3.1)

1 (4.0)

0

No blinding

10 (31.3)

7 (28.0)

3 (42.9)

Not specified

8 (25.0)

4 (16.0)

4 (57.1)

TREATMENT GROUPS

Number of groups, n (%)

1

8 (25.0)

8 (32.0)

NA

2

15 (46.9)

15 (60.0)

NA

3**

2 (6.3)

2 (8.0)

NA

Intervention type in the experimental group, n (%)

Parenteral drugs

2 (6.3)

2 (8.0)

0

Enteral drugs

10 (31.3)

7 (28.0)

3 (42.9)

Topical drugs

3 (9.4)

3 (12.0)

0

Interventional radiology

15 (46.9)

11 (44.0)

4 (57.1)

Physiotherapy

2 (6.3)

2 (8.0)

0

Control group treatment (n = 31)^a, n (%)

Placebo, sham interventions

4 (12.5)

4 (16.0)

0

Active drugs

5 (15.6)

5 (20.0)

0

Interventional radiology

13 (40.6)

11 (44.0)

2 (28.6)

Physiotherapy

0

0

0

Surgery

1 (3.1)

0

1 (14.3)

Interventional radiology and surgery

1 (3.1)

0

1 (14.3)

No treatment

7 (21.9)

5 (20.0)

2 (28.6)