Study designs of evaluations included in the review
RCTs and systematic reviews were eligible for inclusion.
Specific interventions included in the review
Comparative studies of one herbal treatment measured against another active drug were included, as were relevant systematic reviews. Parenteral herbal preparations were excluded. The studies in the review examined:
Articulin-F (an ayurvedic herbomineral formulation containing 450 mg Withania somnifera root, 100 mg Boswellia serrata oleo-gum resin, 50 mg Curcoma longa rhizome, and 50 mg zinc) compared with placebo;
a mixture (1:3 or 2:3) of avocado and soybean unsaponifiables (ASU) compared with placebo;
capsaicin cream compared with placebo or vehicle cream;
Devil's claw (Harpagophytum procumbens, 670 to 800 mg, three times daily) compared with placebo;
Eazmov 50 mg (an ayurvedic herbal preparation containing Cyperus rotundus, Tinosporda cordifolia, Saussurea lappa, Picrorrhiza kurrow and Zingiber officiniale) compared with 50 mg diclofenac;
ginger extract (170 mg Eurovita extract 33, three times daily) compared with ibuprofen and placebo;
Gitadyl (a herbal preparation containing 110 mg feverfew, 90 mg American aspen, and 60 mg milfoil) compared with ibuprofen;
Phytodolor (a fixed herbal preparation containing alcoholic extracts of Populus tremula, Fraxinus excelsior and Solidago virgaurea; 30 or 40 drops, three times daily) compared with diclofenac 25 mg, three times daily, placebo or piroxicam (20 mg/day);
Reumalex (a herbal medicine containing 100 mg Pulv White Willow bark, 40 mg Pulv Guaiacum Resin BHP, 35 mg Pulv Black Cohosh BHP, 25 mg Pulv Ext Sarsparilla 4:1 and 17 mg Pulv Ext Poplar Bark 7:1) equivalent to 20 to 40mg/day salicylic acid compared with placebo;
stinging nettle leaf compared with white deadnettle leaf.
The duration of the treatments ranged from 2 weeks to 6 months.
Trials lacking in methodological details such as dosage descriptions were excluded.
Participants included in the review
Patients with osteoarthritis. Studies focusing exclusively on back pain and osteoarthritic conditions of the spine, including cervical spondylosis, were excluded. Studies of animals were also excluded.
Outcomes assessed in the review
All outcomes reported (subjective or objective) were included in the review. Trials that did not include baseline data and clinical end points were excluded.
How were decisions on the relevance of primary studies made?
All potential articles (or abstracts if only available as abstracts) were read in full; the authors were contacted, where possible, for any additional information that was required. All articles were read by two reviewers, and any disagreements were resolved by discussion.