Specification of interventions and selection of controls in randomized controlled trials of acupuncture: a cross-sectional survey

Objective: Specification of interventions and selection of controls are two methodological determinants for a successful acupuncture trial. However, current practice with respect to these two determinants is not fully understood. Thus, we conducted a cross-sectional survey to examine the specification of interventions and selection of controls among published randomized controlled trials (RCTs) of acupuncture. Study design and setting: We searched PubMed for acupuncture RCTs published in core clinical journals and complementary and alternative medicine (CAM) journals from January 2010 to December 2019 (10 years) and included RCTs that assessed treatment effects of acupuncture versus any type of control. We used network meta-analyses to explore whether there were differential treatment effects in patients with chronic pain when using sham acupuncture as a control versus using waiting list or no treatment. Results: Most of the 319 eligible RCTs specified well the style of acupuncture (86.8%), traditional acupuncture point locations (96.2%), type of needle stimulation (90.3%) and needle retention time (85.6%). However, other acupuncture details were less-frequently specified, including response sought (65.5%), needle manipulation (50.5%), number of needle insertions (21.9%), angle and direction of insertion (31.3%), patient posture (32.3%) and co-interventions (22.9%). Sham acupuncture (41.4%) was the most frequently used control, followed by waiting list or no treatment (32.9%). There was no differential treatment effect when using sham acupuncture versus waiting list/no treatment as a control (standardized mean difference = −0.15, 95% confidence interval: −0.91 to 0.62). Conclusion: Over a decade of research practice, important gaps have remained in the specification of acupuncture interventions, including response sought, needle manipulation, and co-interventions. While sham acupuncture has been widely used, waiting list or no treatment may also be considered as an appropriate control.