Complexities and considerations in conducting animal-assisted intervention research: A discussion of randomized controlled trials

The field of human-animal interaction (HAI) has experienced prolific growth in the scope, breadth, and rigor of research conducted on animal-assisted interventions (AAIs). As knowledge regarding the preliminary efficacy of AAIs on outcomes of human health and wellbeing continues to accumulate, so has information regarding the feasibility, safety, and acceptability of AAIs. This progression, combined with an increase in funding opportunities, institutional resources, and growing recognition of the field from mental and medical health professionals, has led to more widespread implementation of randomized controlled trials (RCTs) in the field. While conducting RCTs in any field of study is an intensive and complex undertaking, researchers conducting RCTs to evaluate the efficacy of AAIs are faced with unique considerations. The goal of this manuscript is to discuss these complexities and considerations surrounding conducting an RCT of an AAI program in regard to study planning, conceptualization, design, implementation, and dissemination. We highlight common confounders in HAI research and provide strategies for minimizing or ameliorating them. Recommendations pertain to such unique issues as ethical considerations, theory, control and comparison groups, sampling, implementation fidelity, and transparent reporting of findings. These considerations and recommendations seek to aid HAI researchers in the design, implementation, and dissemination of future RCTs to continue to advance the rigor of the field.