Table 1.
Overview on the review sets included in the analysis
| Intervention and condition | Control group interventions | Number of studies included (total included in any of the reviews)*—review publication years | Main reasons for discrepant numbers |
|---|---|---|---|
| Acupuncture | |||
| Acupuncture for chronic pain | Sham, other treatment | 14 [Ref. 11], 46 [Ref. 12] (48)-1989-1990 | S, IC |
| Acupuncture for neck pain | Sham, other treatment | 11 [Ref. 13], 5 [Ref. 14] (11)-1999-2000 | S (IC) |
| Acupuncture for low back pain | Sham, no/other treatment | 10 [Ref. 15], 11 [Ref. 16], 8 [Ref. 14] (11)-1998-2000 | IC, S |
| Acupuncture for tension-type headache | Sham, other treatment | 7 [Ref. 17], 8 [Ref. 18], 6 [Ref. 19] (9)-1999-2000 | IC |
| Acupuncture for migraine prophylaxis | Sham, no/other treatment | 6 [Ref. 20], 16 [Ref. 18] (16)-1999 | IC |
| P6-stimulation for postoperative nausea | Sham, no/other treatment | 18 [Ref. 21], 19 [Ref. 22] (24)-1996-1999 | IC, PD |
| P6-stimulation for morning sickness | Sham, no treatment | 7 [Ref. 21], 4 [Ref. 23], 7 [Ref. 24] (8)-1996-1999 | IC |
| Acupuncture for tinnitus | Sham, other treatment | 6 [Ref. 25], 6 [Ref. 26] (7)-1999-2000 | — |
| Herbal medicine | |||
| Ginkgo for intermittent claudication | Placebo | 5 [Ref. 27], 8 [Ref. 28] (9)-2000 | IC, S |
| Hypericum for depression | Placebo, standard | 14 [Ref. 29, 27 [Ref. 30], 6 [Ref. 31], 14 [Ref. 32], 8 [Ref. 33] (29)-1997-2000 | IC (PD) |
| Garlic for cholesterol lowering | |||
| new review set | Placebo | 13 [Ref. 34], 37 [Ref. 35] (37)-2000 | IC, S |
| old review set | Placebo | 5 [Ref. 36], 13 [Ref. 37] (13)-1993-1994 | IC, S |
| Echinacea for colds | Placebo | 13 [Ref. 38], 13 [Ref. 39] (15)-1999 | — |
| Peppermint oil for irritable bowel syndrome | Placebo | 7 [Ref. 40], 3 [Ref. 41] (8)-1998-2000 | S, SE |
| Homeopathy | |||
| All homeopathy for any disease | Placebo | 89 [Ref. 42], 36 [Ref. 43], 16 [Ref. 44] (97)-1997-2000 | IC |
| All homeopathy for any disease | Placebo, other treatment | 40 [Ref. 45], 105 [Ref. 46] (405)-1990-1991 | IC |
| Arnica for trauma | Placebo | 35 [Ref. 47], 8 [Ref. 48] (35)-1998 | IC, SE |
S=Search; IC=inclusion and exclusion criteria; PD=publication date; SE=application of inclusion criteria in the selection process
*
Reviews ordered according to ascending publication year