Clinical Physicians and Factors Associated With Opening Clinics: An Analysis of National Physician Census Surveys in Japan

Background and objective In Japan, clinics play a key role in providing primary medical care. Data on temporal trends in the number, proportion, and characteristics of clinical physicians, as well as factors associated with the opening of clinics in Japan, have not been adequately explored. This study aimed to analyze the temporal trends as well as factors associated with the opening of clinics in Japan. Methodology This study employed a longitudinal study design. Data from the biennial national physician census surveys from 1996 to 2016 were analyzed. It involved all physicians in Japan. As the primary and secondary outcome measures, temporal trends in the number and percentages of physicians were estimated and logistic regression was used to analyze physicians opening clinics. Results Recently, the rate of increase in the number of clinical physicians in Japan has been decelerating, and the proportion of older clinical physicians has been increasing. Specifically, the number of clinical physicians increased in the first decade, from 81,888 in 1996 to 95,213 in 2006, but decreased in the second decade to 102,453 in 2016. Apparently, clinical physicians were aging: the number of clinical physicians aged 39 years or younger decreased by 48%, while those aged between 55 and 69 years increased by 91%. The physician-related factors associated with opening clinics include belonging to the age group of 40-54 years, being male, and having an urban area to practice. As of 2016, 39.1% held no board-certified qualifications, whereas 17.1% held board-certified qualifications in areas other than their specialization. Conclusion This study based on national surveys revealed that the rate of increase in doctors in Japanese clinics is slowing down and that the proportion of elderly doctors is increasing. The physician-related factors associated with opening clinics include being middle-aged, male gender, and the availability of an urban area for practice.