A randomised cross-over pilot study investigating the use of acupuncture to promote weight loss and mental health in overweight and obese individuals participating in a weight loss program

Abstract

Background

Acupuncture is widely used as an alternative modality for weight loss. Despite its increasing use, few acupuncture studies have evaluated the effect of a weight loss program on the mental health of obese/overweight participants and none have looked at the effect on those with eating, weight and shape concerns.

Objectives

To investigate the feasibility of conducting an acupuncture study involving overweight or obese individuals undertaking a weight loss program with particular reference to those with eating concerns.

Methods

Thirty-five overweight/obese males and females participated in a single-blinded randomised cross-over study. The two intervention phases were: (1) nutritional counselling plus Traditional Chinese Medicine (TCM) acupuncture and (2) nutritional counselling plus sham acupuncture.

Outcome measures

This study evaluates the feasibility and practicalities of the study including recruitment, retention, adverse events, effectiveness for defining eating and weight concerns, study design and statistics for power calculations.

Conclusion

The outcome measures, the recruitment of those with eating and weight concerns and the acceptability of the intervention demonstrate a larger trial investigating the use of acupuncture for weight loss in those who have elevated eating and weight concerns is feasible.

Appendix 1: Understanding the analysis of a cross-over trial

Cross-over studies have a couple of issues that need to be addressed in the analysis. They are carry-over [“Carry-over is the persistence (whether physically or in terms of effect) of a treatment applied in one period in a subsequent period of treatment” [25].] and a period effect (“Period effect is where a trend affecting the experiment as a whole” [25]) which looks at the effect of the order with which the participant received the treatment.

The approach detailed in “Study design” of Jones and Kenward was followed [42] to address these issues. This approach consists of first performing a t test for the presence of a carry-over effect in those who received acupuncture in the first phase of the trial. The presence of carry-over is tested using a two sample t test for equality of means of $Y_{1} + Y_{0}$ between those that received acupuncture first and second (page 24, [42]). This approach caters for random effects.

If significant carry-over effects are found, then following the approach of Jones and Kenward (page 28, [42]) the effect of the treatment is measured using a two sample t test on period 0 (both groups first phase only) results only. This tests for equality of means of those who received acupuncture first and those who received sham first.

If no significant carry-over is found, then, another t test is performed for period effect. The presence of a period effect is tested using a two sample t test for equality of means (crossover difference) of $Y_{1} - Y_{0}$ for those that received acupuncture first and $Y_{0} - Y_{1}$ for those that received acupuncture second (page 27 [42]).

If significant period effects are found, then following the approach of Jones and Kenward (page 25, [42]), the effect of the treatment is measured using a two sample t test for the equality of the two means: $Y_{1} - Y_{0}$ for those that received acupuncture first and $Y_{1} - Y_{0}$ for those that received acupuncture second.

If no significant period effect is found then following the approach of Senn (page 42, [25]) the effectiveness of the acupuncture can be measured using a paired t test. $\left( {\begin{array}{*{20}c} {Y_{1} - Y_{0} } \\ {Y_{0} - Y_{1} } \\ \end{array} } \right)$, where $Y_{1} - Y_{0}$ is for acupuncture second and $Y_{0} - Y_{1}$ for acupuncture first. This pools the groups together and a t test is done for zero means.