Clinical evaluation of aromatherapy

This paper addresses how the clinical effectiveness of aromatherapy may be evaluated. Aromatherapy may work through a mixture of physiological and psychological processes. These may work in synergy. Any evaluation must also be conducted in the messiness of the clinical situation and must be economic, i.e., there are not the resources to conduct the large scale randomised double-blind trials typical of pharmaceutical testing.

The different oils used and ailments treated, and the consequent different environmental, psychological and physiological factors, and different clinical situations suggest that each intervention will have to be specifically designed. However, all evaluations will involve common problems of confounding factors and of inferring causality in real-world situations, e.g., due to expectations, placebo, measurement error, small patient numbers and the limitations of double-blind procedures.

This paper illustrates how the principles of research design can be used to counter these problems with reference to the conventional case study.