The present study demonstrates that the density of judo therapy facilities per population unit has increased, irrespective of area, from 2004 to 2008 along with the increase in the absolute number of judo therapy facilities. In particular, the extent to which judo therapy facilities per population unit increased in 2008 was statistically significant and higher than that in 2006 by a factor of more than 1.5. However, this increase in 2008 did not reflect equality in the geographic distribution of judo therapy facilities according to the Gini index. Rather, it reflects a trend toward increased geographical gaps between urban areas and the rest of Japan in 2008.
These findings are important because under the current laws and regulations governing medical delivery systems, the Japanese government cannot intervene in choices about where medical practitioners practice. For example, Japan's physician manpower policy during the 1970s involved increasing the number of medical students and medical schools from 65 to 79 to address the shortage and maldistribution of physicians resulting in communities without doctors. The number of newly certificated physicians increased from approximately 4,000 to 8,000 per year by the mid-1980s. However, the inequality in physician distribution did not improve between 1980 and 1990 according to a previous Japanese study , suggesting that simply increasing the supply of medical providers does not constitute an advisable health policy. Rather, a policy that alleviates the maldistribution of medical providers should be developed. In the present study, the Gini indices significantly decreased in all areas and in urban areas only in 2006, even though the extent to which judo therapy facilities per population unit increased during this year was lower than that during 2008. Because the number of judo therapy facilities per population unit has remained at greater than 20 per 100,000 in urban areas since 2008, it seems clear that the rapid and substantial growth in the number of qualified judo therapists might not naturally match the geographic distribution of the need for judo therapy facilities.
In the present study, national data were not used for two reasons, even though all judo therapists are required to report to the designated public health center. First, the statistics on judo therapists are organized according to each public health center but not according to each municipality . Second, these data were not completely accurate insofar as they might have included defunct businesses because reporting closures of these facilities is not required [14, 15]. We finally decided to gather information about judo therapy facilities from the Townpage of each municipality, and the number obtained via this method was within 5% of the number of judo therapy facilities in all prefectures reporting health insurance payments. The number of facilities may represent a good surrogate for the number of therapists because in most cases, each facility contains only one practicing judo therapist. Using registration data obtained from the Japanese Judo Therapists' Association , we estimated that an average of 1.09 therapists worked in each facility during the period studied.
Before making remarks, several limitations should be noted. First of all, this study is not an analysis of the economics of service provision, but a use of a particular descriptive technology in assessing distributions of judo therapy facilities. Spatial inequality matters are largely due to the time price associated with any health facility, as well as other economic phenomenon including spatial access to health facilities [26, 27]. Because geographical distribution of medical service provider directly relates to urgent need of human life in the community, distribution per se should be analyzed apart from economics. Financial aspects of Judo therapy facilities are important but beyond our scope requiring totally different data set and method for analysis. Thus the results of time-changes in geographic distribution of judo therapy facilities were simply shown in this study. In the future a variety of economic factors need to be considered to interpret our results before approving or opposing health-care policy for the number of judo therapy facilities. Second, this study is limited by its use of a municipality-based method to determine the number of judo therapy facilities and residents; the scale and nature of the facilities could not be assessed. These were grouped data, and the possible effects of 'ecological fallacy' should also be firmly considered for the interpretation of the results . Also, the number of judo therapy facilities was divided by 100,000 people as the only indicator of 'need'. This was because the national data of health-care facilities have usually been published as a unit of per 100,000 residences in Japan, but we should bear in mind that different 'needs' indicators normally produce different inequality estimates: all of which have implications for health policy and planning competing health priorities. Third, the effects of unions of municipalities on the Gini indices should be considered. The Gini index is itself affected by the number of subjects analyzed [17, 18], and the indices for small towns and villages are smaller when such towns or villages are combined into larger cities. However, the number of united cities, towns, and villages was limited (= 27) from 2006 to 2008 and does not appear to account for changes in the geographical differences characterizing Japan in 2006. Fourth, four-year study period was relatively short to observe the change of distribution of judo therapy facilities. However, we were specifically interested in the change of distribution of judo therapy facilities from the start of drastic change of graduates qualifying as judo therapists (i.e., the years 2004 to 2006) in this study, and we recognize that the future study should be continued to observe the distribution of judo therapy facilities.
In spite of these limitations, we demonstrated that judo therapy facilities are widely but unevenly distributed. We suggest that recent increases in the number of judo therapy facilities do not necessarily lead to amelioration of inequalities in their geographic distribution. A large portion of elderly individuals live in nonurban areas, and this fact seems to reinforce the need for judo therapy in such areas . Geographic distributions of health services are affected by forces of demand and supply, and in the future we would like to assess the needs for judo therapy and the number of qualified judo therapists comprehensively in all regions before considering intervention plans to motivate judo therapists to practice in the underserved local areas.