Human resource challenges for physical therapists in Japan: a hybrid time-series and system dynamics analyses for the near, mid and long-term horizons

Introduction There have been growing concerns that the present annual supply of more than 14,000 physical therapists in Japan may signal a potential human resource challenge. The assumption that any increase in supply would be sustained by an increase in demand from an aging population has never been adequately investigated. Purpose The aim of this study was to investigate the human resource challenges faced by physical therapists in Japan, and to develop forecasting models (low, mid and high-growth) for the near (5-year), mid (20-year) and long-term (40-year) event horizons. Methods All human resource data were extracted from publicly available sources from January to May 2020 and categorized according to actual and forecasted supply and strength of demand variables using s system dynamics approach. The actual supply variables were used to validate the forecasted supply using time-series analysis. Results The increase in forecasted supply is expected to be most severe for the high growth scenario, particularly after the mid-term horizon. The forecasted strength of demand may be expected to decrease in both the total and aged populations. Conclusion The increase in supply of PTs in Japan over the past 55-year period, and the forecasted increase over the next 45 years is still a cause for concern. The assumption that any increase in supply would be sustained by an aging population was not supported by the results of this study. These results also suggest that the possibility of a human resource challenge may arise after the mid-term event horizon.