Stimulated by Mu et al 2020.[1]
cLBP –chronic non-specific low back pain
key to acronyms
SRs – systematic reviews
There was no choice for me this week, after 15 years Andrea has finally succeeded (with help from Hong Kong and elsewhere) in updating her much cited Cochrane review of 2005.[2] Whilst the choice was easy, the task is not. As a reviewer myself I dive in and out of these huge feats of academic work as someone who knows how to navigate the landscape, but when I talk about this aspect of systematically reviewing evidence the majority of the audience take on an other-worldly appearance.
search for and include all the data possible and treat it all fairly
I first engaged with systematic reviews (SRs) in the 90’s, when my mentor Adrian White told me I had no choice but to actually do one on my favourite clinical topic – myofascial trigger point pain. I guess it was easier then – the principles were clear, and the methods and the rules were limited. The key principle was to search for and include all the data possible and treat it all fairly. But how do you add it all up?
In the early days we had vote counting, ie how many positive trials were there, and how many neutral or negative ones. If there were more positive than the rest you might claim a positive result overall. It wasn’t long before meta-analysis was introduced, and we got pooling of results presented in the now so familiar forest plot.
Cochrane introduced a highly conservative system for qualitative reviews, and thus it was almost inevitable (with hindsight) that the first Cochrane review of acupuncture for LBP concluded that acupuncture was not effective,[3] despite coming fast on the heels of the first meta-analysis of acupuncture in LBP, which was vaguely positive.[4]
As unsatisfactory as the first Cochrane review on acupuncture for LBP had been, the second was another story. We went from a 21-page review in 1999 to a whopping 143 pages in 2005, and the latest offering runs to 170 pages, but is one of two reviews now – we are expecting a second review on acute LBP to pair with this one on cLBP.
“Oh you mean Andrea, yeah she’s cool, she’s from Brazil.”
Andrea Furlan is a physiatrist and epidemiologist based in Toronto, but she is originally from Brazil, and studied medicine in São Paulo before heading to McMaster to do a PhD in clinical epidemiology. It was whilst doing the latter that she led the epic 2005 Cochrane review. I was surprised to learn that she was from Brazil from one of her contemporaries whilst sitting down to a rather tropical breakfast at a conference in Porto de Galinhas in 2009. I dropped the name Furlan into the conversation as I praised her immensely thorough review, and my Brazilian acquaintance said, “Oh you mean Andrea, yeah she’s cool, she’s from Brazil.” I was sitting opposite a rather young-looking female professor of physiatry from São Paulo. Social media had not fully risen at that point, so there were not many researchers I knew by appearance, country of origin etc at the time.
Since I now had met one of her mates from back home, I was then happy to drop her an email directly, and that is why I have been waiting 15 years on tender hooks for the next episode in the Cochrane cLBP acupuncture story. It nearly happened 10 years ago, but funding support fell through as I recall she told me.
Various things have changed since 2005. There is more data of course (33 studies and 8270 participants versus 35 and 2861), and the big trials from Germany in the noughties have a dominant effect. The authors note this in their abstract, saying that 67% of participants in the review (n=5572) come from 7 trials performed in Germany.
clinically important change
Probably the main difference though is the adoption of clinically important change,[5] and applying it to pooled mean differences. Whilst this is not unexpected, it is for me the most disappointing aspect of this review. The 2-point reduction on a 0 to 10 scale suggested by Dworkin et al refers to the pre–post difference for an individual not the group mean difference at the end of a course of treatment, especially when both groups have received a needling intervention.
To quote directly from Dworkin et al:
It is crucial to recognize that criteria for clinically important change in individuals cannot be directly applied to the evaluation of clinically important group differences.
Dworkin et al 2008 [5]
I have emailed Andrea to ask about this, and to invite her to the Wednesday webinar.
References
1 Mu J, Furlan AD, Lam WY, et al. Acupuncture for chronic nonspecific low back pain. Cochrane Database Syst Rev 2020;12:CD013814. doi:10.1002/14651858.CD013814
2 Furlan AD, van Tulder MW, Cherkin D, et al. Acupuncture and dry-needling for low back pain. Cochrane Database Syst Rev 2005;:CD001351. doi:10.1002/14651858.CD001351.pub2
3 van Tulder M, Cherkin D, Berman B, et al. Acupuncture for low-back pain. In: Cochrane Database of Systematic Reviews. Chichester, UK: John Wiley & Sons, Ltd 1999. CD001351. doi:10.1002/14651858.CD001351
4 Ernst E, White AR. Acupuncture for Back Pain. Arch Intern Med 1998;158:2235. doi:10.1001/archinte.158.20.2235
5 Dworkin RH, Turk DC, Wyrwich KW, et al. Interpreting the Clinical Importance of Treatment Outcomes in Chronic Pain Clinical Trials: IMMPACT Recommendations. J Pain 2008;9:105–21. doi:10.1016/j.jpain.2007.09.005
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