Table 1 Characteristics of the included trials
From: Placebo design in WHO-registered trials of Chinese herbal medicine need improvements
Category | Descriptive Characteristics | N = 363 (%) |
|---|---|---|
CHM interventions | Single herb | 42 (11.6) |
CHM formula | 321 (88.4) | |
Dosage form a | Granule | 136 (37.5) |
Capsule | 49 (13.5) | |
Decoction | 41 (11.3) | |
Pill | 25 (6.9) | |
Tablet | 23 (6.3) | |
Powder | 15 (4.1) | |
Injection | 8 (2.2) | |
Cataplasm | 4 (1.1) | |
Plaster | 4 (1.1) | |
Oral-liquid | 3 (0.8) | |
Ointment | 3 (0.8) | |
Mixture | 1 (0.3) | |
Not reported | 56 (15.4) | |
Administration route | Oral | 348 (95.9) |
External b | 15 (4.1) | |
Conditions studied (ICD-10 codes) c | Diseases of the circulatory system | 45 (12.4) |
Diseases of the digestive system | 36 (9.9) | |
Certain infectious and parasitic diseases | 35 (9.6) | |
Diseases of the musculoskeletal system and connective tissue | 33 (9.1) | |
Diseases of the respiratory system | 33 (9.1) | |
Diseases of the genitourinary system | 30 (8.3) | |
Mental and behavioural disorders | 29 (8.0) | |
Neoplasms | 28 (7.7) | |
Endocrine, nutritional and metabolic diseases | 23 (6.3) | |
Diseases of the nervous system | 20 (5.5) | |
Diseases of the skin and subcutaneous tissue | 15 (4.1) | |
Symptoms, signs and abnormal clinical and laboratory findings not elsewhere classified | 9 (2.5) | |
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism | 7 (1.9) | |
Diseases of the eye and adnexa | 5 (1.4) | |
Factors influencing health status and contact with health services | 5 (1.4) | |
Certain conditions originating in the perinatal period | 4 (1.1) | |
Injury, poisoning and certain other consequences of external causes | 3 (0.8) | |
Pregnancy, childbirth and the puerperium | 2 (0.6) | |
Congenital malformations, deformations and chromosomal abnormalities | 1 (0.3) | |
Specialist classification | Internal medicine | 288 (79.3) |
Gynecology | 30 (8.8) | |
Surgery | 24 (6.6) | |
Pediatrics | 11 (3.0) | |
Orthopedics | 10 (2.8) | |
Diagnosis included TCM syndrome d | Yes | 108 (29.8) |
No | 255 (70.2) | |
Ethics approval | Yes | 251 (69.1) |
No | 18 (5.0) | |
Not reported | 94 (25.9) | |
Study phase e | Phase 1 | 52 (14.3) |
Phase 2 | 60 (16.5) | |
Phase 3 | 34 (9.4) | |
Phase 4 | 55 (15.2) | |
Others | 162 (44.6) | |
Control arm f | Solely placebo as control | 191 (52.6) |
Add on control with baseline treatment | 84 (23.1) | |
Double dummy-control g | 57 (15.7) | |
With active control arm | 43 (11.8) | |
With healthy control arm | 6 (1.7) | |
Sample size of placebo group h | 1–100 | 239 (65.8) |
101–300 | 107 (29.5) | |
301–500 | 12 (3.3) | |
> 500 | 5 (1.4) | |
Administration time of placebo | ≤ Half month | 12 (3.3) |
≤ Three months | 83 (22.9) | |
≤ Six months | 30 (8.3) | |
≤ One year | 14 (3.9) | |
> One year | 9 (2.5) | |
Not reported | 215 (59.2) | |
Outcomes | Subjective items only | 10 (2.8) |
Objective items only | 121 (33.3) | |
Both of objective and subjective items | 229 (63.1) | |
Not reported | 3 (0.8) | |
With TCM-related outcomes i | 119 (32.8) | |
Adverse effects reported | 114 (31.4) |