Analysis of the numbers of clinical trials on physical therapy in Japan: comparison with those in the North American register from 2010 to 2019.

[Purpose] Information about clinical trials related to physical therapy (CTPT) in Japan, which has the highest aging rate in the world, is essential for physical therapy education, research, and policymaking to change and strengthen the education system and promote research grants. This survey aimed to clarify the proportion of CTPT in the clinical registry and compare the proportion of CTPT in Japan with that in North America. [Participants and Methods] The ClinicalTrials.gov (CTG) and National Institute of Public Health (NIPH) Clinical Trials were used. The number and proportion of CTPT were compared each year. The analyzed data spanned 10 years from 2010 to 2019. [Results] A total of 222,821 trials were registered in CTG during the 10 years. In search of "physical therapy", 3,001 trials searched. The proportion of CTPT increased from 0.8% to 1.7%. In total 42,194 trials were registered in the NIPH Clinical Trials Search. From the CTPT, 141 trials were obtained. The proportion of CTPT increased from 0.05% to 0.5%. The proportion of CTPT in the NIPH Clinical Trials Search was one-third or less than that in the CTG. The proportion of CTPT in CTG increased yearly, but the proportion of CTPT in NIPH Clinical Trials Search has not increased since 2016. [Conclusion] The proportion of CTPT is relatively low in Japan, compared with that in North America, and it showed no increasing trend. It is important to provide education and support for clinical trials in an aging country such as Japan.