Although survival rates for children diagnosed with cancer have increased dramatically over the past 40 years, hard evidence of proven psychosocial benefits to improve quality of life among patients and families during treatment has remained elusive.

Many hospitals have therapy dogs who visit with patients, and anecdotal evidence underscores the positive impact these programs have on with cancer and their families. Preliminary findings from a new, multi-center trial provides some of the first to validate these claims.

The study, to be presented at the American Academy of Pediatrics (AAP) National Conference & Exhibition in Washington, DC, collected data on blood pressure, pulse rates and of children before and after a weekly visit from a therapy dog. During the visits, children pet or talk to the dog, brush its fur, view the dog's photos, watch the dog practicing tricks or commands, and learn about dog breeds.

Preliminary findings show that blood pressure readings in the group receiving animal-assisted interventions remains more stable across all sessions than in the control group, said lead researcher Amy McCullough, Ph.D., National Director of Humane Research and Therapy for the American Humane Association. Similarly, there was a higher degree of variability in heart rate within the control group patients than with the treatment group patients.

"These findings suggest that the dog may have a calming effect on the patient," Dr. McCullough said.

Even as animal-assisted interventions happen daily in today's pediatric oncology settings, rigorous studies of the effectiveness of pet therapy programs are lacking. This national, multi-site study is the first of its kind to rigorously measure the psychosocial effects of the encounters, McCullough said.

To date, 68 children ages 3 to 17 who are newly diagnosed with cancer have been enrolled in the study, including 39 in the treatment group and 29 in the control group —roughly half the amount expected to participate by the time the study concludes in 2016.

In addition to the effects on pulse and heart rate to date, preliminary results indicate the canine encounters appear to improve anxiety levels among parents. Parents in the report fluctuating anxiety levels with peaks and valleys; parents in the treatment group show more consistency in anxiety levels, and even a small decline in anxiety levels by the end of their participating in the study. Overall, children in both groups saw a decrease in anxiety over the course of their study enrollment. Researchers are also gauging the ' temperament and behavior during the visits.

"This study will be a milestone in understanding of the benefits of the vital bond shared between people and animals," Dr. McCullough said. The findings are expected to further increase access to therapy animals in hospital environments, enhance therapy dog training and practice, and improve well-being outcomes for children and families facing the challenges of childhood , she said.

More information: The abstract, "The Effects of Animal-Assisted Interventions (AAIs) for Pediatric Oncology Patients, Their Parents, and Therapy Dogs at Five Hospital Sites," will be presented at 3:40 p.m. on Sunday, Oct. 25, in the Congress/Capitol Room of the Washington Marriott Marquis. To view the abstract, aap.confex.com/aap/2015/webpro … nary/Paper30412.html