MA vs TENS in PGP

Inspired by Svahn Ekdahl et al 2021.[1]

Image by Janko Ferlič on Unsplash.

MA – manual acupuncture
TENS – transcutaneous electrical nerve stimulation
PGP – pelvic girdle pain
NIHR – National Institute of Health Research
ODI – Oswestry disability index
ITT– intention to treat
PP – per protocol
CI – confidence interval
QoL – quality of life

key to acronyms

There was a flurry of research activity on PGP in pregnancy started by Helen Elden in the noughties, most notably with her 2005 paper in the BMJ.[2]

PGP in pregnancy

She went on to publish a variety of further papers on the topic including a neutral sham-controlled trial using the Streitberger needle.[3–9] I remember that she was the first researcher to comment to me that the patients very often bled in the sham treatment group despite the use of ‘non-penetrating’ needles, and the size of the change in both groups of this trial was similar to that of the acupuncture group in her first trial.

Sometime after this research, and my conversation with Helen, I was invited to participate in a protocol development group for a relatively large funding call from NIHR Health Technology Assessment programme in the same subject area. I was strongly opposed to a standard sham controlled trial, and we developed an ingenious protocol for a large pragmatic trial with a nested efficacy trial using real and sham laser as well as needle acupuncture. I was quite excited by the potential of this trial, but it turned out to be too complicated for the reviewers to understand and the money went to another group that simply proposed a standard parallel arm, sham controlled trial using Streitberger needles.

So a lot of money was spent on a feasibility trial,[10] even though in my opinion, any subsequent trial of the same design would never have reached the necessary power to measure a difference between real and sham acupuncture.

More recently we have seen a couple of nice papers on PGP in pregnancy. One was a trial of ear acupuncture from Spain,[11] possibly the last from our good friend Jorge Vas; and the second was a thorough cost effectiveness evaluation of acupuncture delivered by midwives in France.[12] Both of these have been mentioned here before:

PGLBP or LBPGP during pregnancy

The current paper comes from the same institution in Sweden as all of those from Helen Elden and colleagues, but it takes a slightly different tack. This is an open parallel arm trial comparing 10 sessions of acupuncture over 5 weeks with daily TENS applied to the area of pain. It is a moderate sized trial with 113 participants divided equally and randomly between 2 groups.

There were rather a lot of outcome measures used, but the primary outcome was the ODI. A quick look at the results in the abstract gave me an impression that there was a non-significant trend in favour of TENS. I looked more carefully at the results in the paper, and whilst there was no statistically significant difference between the groups in either the ITT or PP analysis, the mean value of the deterioration in ODI was over 7 times larger in the TENS group. The lack of significance was due to wide CIs, but the mean change in the TENS group was certainly clinically significant in magnitude. The lower CI for the TENS mean change was positive, meaning that at least 95% of the women deteriorated over the course of treatment. The CIs for the acupuncture group spanned zero change fairly evenly meaning that some women in this group had a clinically meaningful improvement.

Perhaps most telling is that QoL measured with the EQ-5D was maintained in the acupuncture group but deteriorated significantly in the TENS group (PP analysis).

Ultimately it is not an either-or choice of course, and it would have been nice to see a group using both acupuncture and TENS. Having said that, 3 groups would have reduced the statistical power further, and what this trial really needed was more power not less.

I will go through the figures in more detail at the blog webinar on Wednesday and try not to make it too much of a fishing trip :D.

References

1          Svahn Ekdahl A, Fagevik Olsén M, Jendman T, et al. Maintenance of physical activity level, functioning and health after non-pharmacological treatment of pelvic girdle pain with either transcutaneous electrical nerve stimulation or acupuncture: a randomised controlled trial. BMJ Open 2021;11:e046314. doi:10.1136/bmjopen-2020-046314

2          Elden H, Ladfors L, Olsen MF, et al. Effects of acupuncture and stabilising exercises as adjunct to standard treatment in pregnant women with pelvic girdle pain: randomised single blind controlled trial. BMJ 2005;330:761. doi:10.1136/bmj.38397.507014.E0

3          Elden H, Fagevik-Olsen M, Ostgaard H-C, et al. Acupuncture as an adjunct to standard treatment for pelvic girdle pain in pregnant women: randomised double-blinded controlled trial comparing acupuncture with non-penetrating sham acupuncture. BJOG Int J Obstet Gynaecol 2008;115:1655–68. doi:10.1111/j.1471-0528.2008.01904.x

4          Elden H, Hagberg H, Fagevik Olsen M, et al. Regression of pelvic girdle pain after delivery: follow-up of a randomised single blind controlled trial with different treatment modalities. Acta Obstet Gynecol Scand 2008;87:201–8. doi:10.1080/00016340701823959

5          Elden H, Ostgaard H-C, Fagevik-Olsen M, et al. Treatments of pelvic girdle pain in pregnant women: adverse effects of standard treatment, acupuncture and stabilising exercises on the pregnancy, mother, delivery and the fetus/neonate. BMC Complement Altern Med 2008;8:34. doi:10.1186/1472-6882-8-34

6          Fagevik Olsén M, Gutke A, Elden H, et al. Self-administered tests as a screening procedure for pregnancy-related pelvic girdle pain. Eur Spine J 2009;18:1121–9. doi:10.1007/s00586-009-0948-2

7          Elden H, Lundgren I, Robertson E. Life’s pregnant pause of pain: pregnant women’s experiences of pelvic girdle pain related to daily life: a Swedish interview study. Sex Reprod Healthc Off J Swed Assoc Midwives 2013;4:29–34. doi:10.1016/j.srhc.2012.11.003

8          Elden H, Östgaard H-C, Glantz A, et al. Effects of craniosacral therapy as adjunct to standard treatment for pelvic girdle pain in pregnant women: a multicenter, single blind, randomized controlled trial. Acta Obstet Gynecol Scand 2013;92:775–82. doi:10.1111/aogs.12096

9          Elden H, Gutke A, Kjellby-Wendt G, et al. Predictors and consequences of long-term pregnancy-related pelvic girdle pain: a longitudinal follow-up study. BMC Musculoskelet Disord 2016;17:276. doi:10.1186/s12891-016-1154-0

10        Foster NE, Bishop A, Bartlam B, et al. Evaluating Acupuncture and Standard carE for pregnant women with Back pain (EASE Back): a feasibility study and pilot randomised trial. Health Technol Assess Winch Engl 2016;20:1–236. doi:10.3310/hta20330

11        Vas J, Cintado MC, Aranda‐Regules JM, et al. Effect of ear acupuncture on pregnancy‐related pain in the lower back and posterior pelvic girdle: a multicentre randomised clinical trial. Acta Obstet Gynecol Scand 2019;:aogs.13635. doi:10.1111/aogs.13635

12        Nicolian S, Butel T, Gambotti L, et al. Cost-effectiveness of acupuncture versus standard care for pelvic and low back pain in pregnancy: A randomized controlled trial. PloS One 2019;14:e0214195. doi:10.1371/journal.pone.0214195


Declaration of interests MC