A related comment notes that most patients (85%) had a first-time carpal tunnel syndrome diagnosis and all had symptoms for at least 6 weeks. Although nerve conduction tests were not used as part of the diagnosis, they note that the trial was pragmatic, and treatment is often given on the basis of a clinical diagnosis in practice. The mean symptom severity score before treatment was >2.9, which is similar to preoperative scores in UK studies, therefore the results may be relevant beyond primary care.
The comment goes on to note that the difference in the primary outcome could be argued to be of small clinical importance (one study showed a mean improvement in symptom severity score of 0.30 associated with a placebo injection), and note that injections are thought to have a larger placebo effect, which could have affected the results. In addition adherence to splinting was self-reported, and as adherence was exclusive to the splinting group, this may also have affected the results. A mean symptom severity score greater than 2.1 at 6 weeks and 6 months suggests many patients still have symptoms.
They conclude that a small treatment benefit in favour of steroid injection should be sufficient to consider injection as a first-line treatment, and that the results of this trial might justify a change in clinical practice in that patients with mild or moderate carpal tunnel syndrome can choose a single steroid injection in primary care instead of night splinting.