We have shown that trends in the HHR ratio of PTs to population has increased by 11.6% between 1991 and 2005 (from 4.3 to 4.8 PTs per 10,000), but that the trend in the latter 5 years (between 2000 and 2005) showed a decrease of 4.0% (from 5.0 to 4.8 PTs per 10,000). The reason for this negative growth trend between 2000 and 2005 is not a function of decreasing number of PTs in Canada – indeed, there were more PTs in 2005 than in any other time period. Rather, the trend may partially be explained by the fact that overall population growth appears to be outstripping the growth in the number of PTs across Canada, but especially in Ontario and British Columbia where the greatest proportional population growth occurred during the 15-year period between 1991 and 2005.
The reasons for the limited growth in HHR ratios of PTs in relation to the population are not clear. When comparing these trend data with those data reported by Landry , it appears that all provinces other than Ontario and British Columbia have maintained a positive growth in HHR of PTs to population. For instance, Landry reported that Ontario and British Columbia had positive growth of 2.2% and 11.7% respectively; however, when compared with estimates made in this study, HHR ratio have decreased from 2.2 to -6.7 in Ontario, and from 11.7 to -1.7 in British Columbia .
As mentioned previously, there were higher absolute numbers of PTs in 2005 than in any previous time period. There are thirteen university training programs across Canada that educates PTs; the majority of these are located in Ontario and Quebec. The five programs in Ontario and the three in Quebec accounted for 65.6% of all graduates in 2004. All thirteen of these educational programs produced 665 PTs in 1995; but by 2004, these programs dropped output by 34 students graduates . Moreover, many of these educational programs have shifted from a bachelor degree to a master entry-level to practice degree during this period of time, which in turn may have contributed to a lowered output of PTs. However, the output of PTs from these education programs appears to have decreased while population growth has increased, and possibly altering the balance between supply and demand for physical therapy services.
The implications and policy interpretation of these findings are complex, and the data collected within this study are not sufficient to establish causation. However critical questions have emerged from this study related to the optimal number of PTs in Canada; for instance, what is the optimal supply of PTs to meet demand across Canada? In other words, is the 2005 national average of 4.8 PTs per 10,000 "high", "low" or "just right"? To our knowledge, there are no needs-based or evidence-based targets or benchmarks regarding the number of PTs per population across settings or conditions. In order to address the question regarding optimal ratios, an analysis of supply and demand for PT is necessary. Demand for health and rehabilitation services are projected to increase in the next decade [24, 25]. However, factors that affect this demand have not been fully explored. It is thus critical to develop a forecasting methodology that will estimate demand across settings (i.e. hospital, home and community sectors) and conditions (i.e. arthritis, and other chronic conditions). Once demand for physical therapy services is established, assessing the degree of alignment between supply and demand will become more empirical.
Moreover, further examination of supply-side issues such as individual and group productivity, relative attractiveness of certain sub-sectors for physical therapy practice, episodic balance between the full-time and part-time workforce, along with the emerging shifts form public to private financing of services require in-depth analysis. As supply and demand variables become established, workforce policy and planning research will also become more empirically based, and much less speculative.