Abstract
Yoga research is growing rapidly in volume and rigor but varies in sample size, study design, and reporting transparency. Yoga professionals may not be versed in the current research due to a lack of research literacy and may not be well positioned to discern research relevance and quality. Research literacy is necessary to apply research in yoga teaching and therapeutics. Research is part of evidence-informed practice, along with clinical experience and client preferences, and is aligned with concepts from yoga philosophy. Several strategies are available to improve research literacy and evidence-informed practice for yoga professionals, which can help to expand inter-professional collaboration and inform the trajectory of yoga research toward better alignment and application to clinical practice. Yoga research reporting guidelines will improve transparency in research dissemination for application to practice, policy, replication, comparison, and summarization.
TopIntroduction
Yoga practice is increasing worldwide. In some countries, practitioners have more than doubled in the last decade (Clarke et al., 2015) and worldwide prevalence is estimated at over 300 million individuals (Montigny, 2018). As the use of yoga expands worldwide, there is a corresponding expansion in the diversity of those who practice yoga. For example, older persons and clinical populations are two groups in which yoga practice is increasing (Clarke et al., 2015). This trend is in a cyclical relationship with yoga research. As more individuals begin to practice, the need for research that verifies its safety in diverse populations also grows. Reciprocally, as research evidence grows regarding the potential effectiveness of yoga for prevention or management of various health conditions, the prevalence of participation increases. In response, published yoga research has grown exponentially in recent decades (Jeter et al., 2015). And while yoga appears to be incredibly safe in clinical trials (Cramer et al., 2015), the rate of yoga injuries is growing (Swain & Mcgwin, 2016). This disconnect may be in part due to the increase in yoga use by older and clinically complicated populations, while the training of yoga teachers worldwide remains focused on teaching relatively young and healthy students. Those delivering yoga in clinical trials, in contrast, are utilizing protocols developed specifically for a target population. The apparent disconnect may also be due to the high risk of bias in yoga research (Cramer et al., 2015).
The need for yoga that is safe and appropriate for diverse populations has been met by the rise in both yoga therapy and accessible yoga. Yoga therapy, while ancient in its origins, has become more codified and professionalized in recent years, including the establishment and growth of the International Association of Yoga Therapists (n.d.), which has developed training competencies, credentialing of schools and professionals, codes of conduct and a scope of practice for the field. Accessible Yoga (n.d.), conversely, is a grassroots movement to foster awareness and access to yoga spaces, teachers, and practices by anyone, regardless of physical ability, mental health status, or demographics. Unfortunately, little research has been done to examine whether the practices of yoga therapy and accessible yoga in real world settings parallels the practices that have suggested safety and acceptability in the growing body of yoga research.
The objectives of this chapter are to first identify the known challenges of bias and research literacy surrounding the current body of yoga literature. Second, these challenges are addressed more specifically within the context of study design, research reporting, and Evidence Informed Practice (EIP). Finally, solutions and recommendations are made to advise on the role the yoga research community might play in improving future yoga research and evidence informed practice.
Key Terms in this Chapter
Comparison Groups (Equal Attention Control, Waitlist Control): In a study design that utilizes a comparison, these are the groups to which the intervention or exposure groups are compared.
Comparative Effectiveness Research: Research that directly compares currently used healthcare interventions to one another to establish which is most useful for a given population.
Methodological Biases: Errors that are systematically introduced during the design, execution, analysis, or reporting of a research study that encourages one set of results over another.
Clinical Trials (Including Double-Blind, Randomized, Placebo-Controlled Trial, Randomized Controlled Trial): A type of study design that assigns participants to an intervention (treatment) or a control/comparison group in order to test the effects or efficacy of the intervention. Clinical trials may involve randomization (the random allocation of participants to groups) and/or blinding, which prevents participants, researchers, or other involved personnel from knowing which participants were assigned to which group.
Placebo Effects: Placebo controls indicate a non-treatment, which ideally has no effect on the participants, but still gives them the impression that they are engaging with a treatment. It follows then that a placebo effect is a positive effect that is still seen, even though the participant is not engaging with an active treatment.
Sample Size: Sample size describes the number of participants within a study. Since we cannot feasibly test everyone in most populations, we rely on a subset or sample of the population who is willing to participate in the study. Researchers will calculate power to determine that they have a large enough sample size in order to achieve significance with the expected effect size.
Attrition: A reduction in the number of participants in a study.
Generalizability: The ability to infer study results taken from a sample to the larger population.
Observational Research: A type of study wherein participants are surveilled or surveyed in an uncontrolled setting. No interventions are applied in this type of study, instead exposures are recorded to determine their association to an outcome. The most common observational study designs seen in biomedical research are cohort, case-control, and cross-sectional designs.
Intervention/Interventionist: The intervention component of a study is the treatment of interest. The interventionist therefore would be the individual tasked with administering the intervention to participants. In the case of a yoga study, the interventionist could be a yoga instructor.