One article on PainSci cites Robertson 2007: Does Arnica Gel Work for Pain?
PainSci commentary on 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 wherever possible.
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.
~ Paul Ingraham
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.
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:
- Association of Lumbar MRI Findings with Current and Future Back Pain in a Population-based Cohort Study. Kasch 2022 Spine (Phila Pa 1976).
- A double-blinded randomised controlled study of the value of sequential intravenous and oral magnesium therapy in patients with chronic low back pain with a neuropathic component. Yousef 2013 Anaesthesia.
- Is Neck Posture Subgroup in Late Adolescence a Risk Factor for Persistent Neck Pain in Young Adults? A Prospective Study. Richards 2021 Phys Ther.
- Sudden amnesia resulting in pain relief: the relationship between memory and pain. Choi 2007 Pain.
- Photobiomodulation therapy is not better than placebo in patients with chronic nonspecific low back pain: a randomised placebo-controlled trial. Guimarães 2021 Pain.