PainSci summary of Robertson 2007?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided at the bottom of the page, as often as possible. ★★★★☆4-star ratings are for bigger/better studies and reviews published in more prestigious journals, with only quibbles. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.
This test of homeopathic (extremely dilute) Arnica montana was conducted by homeopaths and published in a journal for homeopaths, so the risk of the results being bent by bias is as high as it gets. But … it is the right kind of study, on paper at least: a randomized double blind trial of 190 patients over the age of 18 undergoing a tonsillectomy. Subject received either Arnica 30c or a placebo for two weeks.
The Arnica-getters had a slightly larger drop in pain score (28.3 points, on a 100-scale) compared to the placebo group (23.8), so the researchers concluded that this was “a small, but statistically significant, decrease in pain scores compared to placebo.” Sounds okay, right? The right kind of test with modest but clearly positive results?
The effect size is all that matters, and it’s trivial. Emphasizing statistically significance is a red herring. They neglected to mention the well-known principle that statistical significance in tests of highly implausible claims is meaningless (see Pandolfi). So “small but statistically significant” in this context basically means they found nothing at all.
original abstract†Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
OBJECTIVE: To evaluate the efficacy of Homeopathic Arnica in reducing the morbidity following tonsillectomy.
METHODS: Randomised double blind, placebo controlled trial at a tertiary referral centre. 190 patients over the age of 18 undergoing tonsillectomy were randomised into intervention and control groups receiving either Arnica 30c or identical placebo, 2 tablets 6 times in the first post-operative day and then 2 tablets twice a day for the next 7 days. The primary outcome measure was the change in pain scores (visual analogue scale) recorded by the patient on a questionnaire over 14 days post-operatively; Secondary outcome measures were: analgesia consumption, visits to the GP or hospital, antibiotic usage, the day on which their swallowing returned to normal and the day on which they returned to work.
RESULTS: 111 (58.4%) completed questionnaires were available for analysis. The Arnica group had a significantly larger drop in pain score from day 1 to day 14 (28.3) compared to the placebo group (23.8) with p < 0.05. The two groups did not differ significantly on analgesic consumption or any of the other secondary outcome measures (number of post-operative visits to GP, use of antibiotics and secondary haemorrhage readmissions).
CONCLUSION: The results of this trial suggest that Arnica montana given after tonsillectomy provides a small, but statistically significant, decrease in pain scores compared to placebo.
One article on PainScience.com cites Robertson 2007 as a source:
- PS Does Arnica Gel Work for Pain? — A detailed review of popular homeopathic (diluted) herbal creams and gels like Traumeel, used for muscle pain, joint pain, sports injuries, bruising, and post-surgical inflammation
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- The neck and headaches. Bogduk 2014 Neurol Clin.
- Agreement of self-reported items and clinically assessed nerve root involvement (or sciatica) in a primary care setting. Konstantinou 2012 Eur Spine J.
- Effect of NSAIDs on Recovery From Acute Skeletal Muscle Injury: A Systematic Review and Meta-analysis. Morelli 2017 Am J Sports Med.