Background
It is estimated that during the course of a year, approximately 34% of adults experience neck pain, of which a significant proportion is chronic, with about 14% experiencing neck pain for at least six months duration [
1]. As well as the impact it has on individuals at a personal level, there are also significant financial costs associated with neck pain [
2]. In general, evidence is lacking to support many standard treatments for chronic neck pain [
3], and increasingly people are using alternative treatments such as acupuncture [
4,
5].
A systematic review on the effectiveness of acupuncture treatment for neck pain found the evidence to be inconclusive [
6], with some studies producing positive results in favour of acupuncture and others producing negative or equivocal findings. In their systematic review, White and Ernst [
6] documented the poor quality of the reviewed trials, none of which scored full points on the quality assessment used in the review. These findings are reinforced by White et al [
7], who discouraged further reviews on the subject, and argued instead that "the focus must be on actually conducting more clinical trials" of good quality, a view echoed by others in the field [
6,
8‐
10].
Since White and Ernst's review [
6], a number of trials have been conducted. Although they vary considerably in terms of their design, the findings remain inconsistent, with most studies showing some positive results in favour of acupuncture [
4,
11‐
15], some showing negative results [
16,
17], and others showing neutral/equivocal findings [
18,
19]. An examination of these more recent studies reveals the continued existence of many of the methodological difficulties referred to in previous reviews [
6,
7].
In this pilot study, we have focused on establishing the key design features required for a full scale randomised controlled trial of the effectiveness of acupuncture for chronic neck pain, where acupuncture is provided as an adjunct to usual GP care. In particular we aimed to establish: the potential recruitment rate; the level of attendance for, and acceptability of, acupuncture to patients; the variability in the primary clinical outcome measure; and the loss to follow-up. A key outcome of this pilot is the sample size calculation for the full-scale trial. As part of this pilot, we interviewed patients, acupuncturists and GPs to facilitate a fuller understanding of patient and practitioner perspectives, however this qualitative data is not reported here.
Discussion
The pilot study reported here has provided much useful data for the design of a full-scale trial of acupuncture for chronic neck pain. A key finding is that 12.3% of eligible patients on the GP database consented to participate in the trial, a remarkably similar percentage to the 12% found by McCarney et al [
20] in a trial of acupuncture for migraine. Based on the experience of our study, this method will enable a large sample to be recruited to a trial relatively quickly, in comparison with prospective recruitment of incident cases. We also found that a sample size of 458 patients and a GP practice population base of 230,000 would be required in a full-scale trial if GP databases are to be used as a source of identification and recruitment of patients. The evidence from our pilot study suggests that this recruitment strategy is feasible.
We found a trend towards higher levels of satisfaction among those patients referred to acupuncture, compared to those receiving usual GP care alone. All of the patients receiving acupuncture treatment reported high levels of acceptability (with one exception). However, there were some concerns about the safety of acupuncture, specifically the negative reactions to treatment. These included a temporary worsening of symptoms, dizziness, and tiredness, with two patients withdrawing from treatment as a result. Although there were no serious adverse events, defined as "events requiring hospital admission, leading to permanent disability, or resulting in death" [
25], safety is clearly an important issue that should be carefully considered when developing the design of a full-scale trial. We recommend the provision of adequate monitoring of adverse events and clinical supervision for acupuncturists.
The pragmatic design of the trial was also considered appropriate given the widespread use of acupuncture and the fact that this design facilitates economic evaluations [
26]. Trials embedded in real world practice tend to have strong external validity, though often at the expense of weaker internal validity than explanatory trials. Due to the difficulties of blinding in acupuncture research generally, Birch [
10] has highlighted the added importance of ensuring that all stages of analysis are blinded, from data-entry to evaluation of the results. Although impractical for the purposes of this pilot, blinding should be implemented in a large-scale trial, to help avoid the potential for bias [
10].
The recruitment processes used in this pilot were successful as patients were identified and recruited relatively simply and quickly. One limitation of our screening procedures was that one patient with cancer inadvertently entered the trial. This indicated a potential flaw with the search strategy, and a future large-scale trial should consider including a cancer question as part of the screening questionnaire given to patients, if the intention remains to exclude patients with cancer.
This study did not set out to establish whether there were components of acupuncture that had specific efficacy. Instead our design was a pragmatic one, where we are working towards an evaluation of the impact of the overall package of acupuncture care. A different research question could have been used to determine the relative contributions of components of the treatment. To do this, a 'placebo' or sham acupuncture control would be used, to control for the components of treatment that are not specific to acupuncture, such as time and attention. Sham approaches are not suitable within pragmatic trials, since they are artificial controls that do not model usual practice [
27], making it difficult to meaningfully interpret their results [
6]. Sham acupuncture approaches are generally problematic since there is evidence that they can produce a physiological effect that may be therapeutic [
28,
29].
Although the main outcome measure used in this pilot is a validated scale, such self-report measures are subjective. Therefore for a large-scale trial it might be useful to consider including an objective outcome as a secondary measure [
30]. Also, given that there is evidence to suggest that preference and belief might influence outcome [
31,
32], it is recommended that a large-scale trial establishes preference and belief prior to randomisation, so that their potential influence on outcome can be explored in the analysis [
31,
33].
Overall, in terms of generalisability of the trial, the broad inclusion criteria for recruiting patients made it more likely that the patients in the trial were fairly representative of those typically presenting with chronic neck pain. The acupuncture treatment protocol was also fairly broad, though sufficiently standardised to assist replication. Acupuncturists found it sufficiently flexible to allow them to use an individualised approach, reflecting traditional acupuncture as it is usually practiced. The generalisability of acupuncture treatment was further improved by using more than one acupuncturist in the trial.
Acknowledgements
Acknowledgements are due to the patients, the acupuncturists, the GPs, the GP practice staff, Professor David Torgerson, Dr Jeremy Miles and all the others who have participated in this trial and helped bring the study to fruition. Gemma Salter was funded by a Medical Research Council Studentship and Hugh MacPherson is supported by a Department of Health post-doctoral fellowship in complementary and alternative medicine.
Competing interests
The author(s) declare that they have no competing interests.
Authors' contributions
GCS was trial co-ordinator overseeing all aspects of the conduct of the study, including design, data collection, analysis and preparation of the manuscript. HM helped design the study, advised on implementation, and helped draft the manuscript with GS. MR advised on the design, conducted the screening of the GP database, and contributed to revisions of the manuscript. JMB assisted with the data analysis and calculation of proposed sample size. All authors read and approved the final manuscript.