January 16, 2017

acupuncture and colic

New research published in Acupuncture in Medicine reported that acupuncture appears to safely reduce crying in infants with colic. Roundup comments accompanied this analysis.

Title, Date of Publication & Journal

Effect of minimal acupuncture for infantile colic: a multicentre, three-armed, single-blind, randomised controlled trial (ACU-COL)

Landgren K, Hallström I. Acupuncture in Medicine 2017;0:1–9.

Study’s main claims – and are they supported by the data

The paper does not support the claim that acupuncture cures or alleviates colic in babies.

The paper lends very weak support to the claim that minimal acupuncture (a specific type of acupuncture) could provide some benefit for colicky infants. But given the lack of any known biological mechanism that could explain how this effect could work, a stronger statement than that is not plausible.

The methodology for the study is fairly rigorous and the investigators have clearly taken steps to ensure that bias is minimised. However there are concerns regarding how well blinding was maintained in practice, the large number of analyses performed (only a few of which were significant) and the potential bias incurred by combining the two acupuncture groups post hoc. There is also an imbalance between the two groups in terms of the percentage of mothers breast-feeding, which doesn’t appear to have been accounted for in the analysis or discussion.

Strengths/Limitations

The researchers have clearly taken blinding very seriously in this study and have painstakingly documented the steps they took to ensure that parents and nurses did not know beforehand which treatment group the infant had been assigned to. However, Table 5 clearly shows that more parents of infants receiving acupuncture believed that that’s what they were receiving compared to the percentage of parents in the control group who believed they were receiving acupuncture. (If blinding had been completely maintained, we would expect these numbers to be roughly equal.) The authors casually suppose that this was because the parents were observing a benefit of acupuncture but it seems just as likely to be due to other factors such as marks on the skin or drops of blood where the needles had been.

There was a (presumably random) imbalance in breastfeeding between the acupuncture group (62%) and the control group (49%) (Table 1). As the first paragraph implies that diet is an important risk factor for colic it is surprising that this imbalance is not discussed more in the paper or controlled for in the analysis.

At some point during the trial, it was decided that the two acupuncture groups should be combined in the analysis due to external factors (acupuncture becoming available as a matter of routine whilst the trial was ongoing). It is not clear whether this decision was made whilst still blind to the data that had already been collected or not. It is possible that having a look at the data beforehand could have influenced the decision of whether or not to change the planned analyses mid-stream.

It should also be noted that there are a large number of comparisons being performed, increasing the likelihood of a spuriously significant result being observed by chance. The p-values (mostly in the 0.03 to 0.05 range) do not indicate an overwhelmingly strong signal, and as such I suspect that these would cease to be significant if appropriate adjustments for multiple comparisons were made.

Any specific expertise relevant to studied paper (beyond statistical)?

None

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