The ecology of medical care on an isolated island in Okinawa, Japan: a retrospective open cohort study

In 1961, White et al. [1] introduced “the ecology of medical care” or healthcare-seeking behavior per 1000 people in the general population over a 1-month period, as a way to assess the adequacy of medical resources. Although this model is widely referenced by policy makers and educators [2–9], an ecological model is likely to vary given differences in populations, regional areas, and times [10]. In 2005, Fukui et al. [11] reported the ecology of medical care as basic data for healthcare-seeking behavior in Japan using 2003 questionnaire and health diary data; unfortunately, that study did not include referrals data. Referral is an important primary care function, as several dimensions of primary care, particularly access, comprehensiveness, and coordination of primary care services, reduce the number of visits to specialists and emergency departments [12].

Japan has the fastest-growing super-aging population of most developed countries [13]. In 2013, the Japan Ministry of Health, Labour and Welfare highlighted the importance of primary care in managing the aging population [14]. Unfortunately, it is difficult to evaluate the role of primary care in Japan using the ecology of medical care model, as Japan has a “free access system” that guarantees access to all medical facilities. Therefore, people can bypass primary care clinics and visit secondary or tertiary medical services directly. This is notable in urban areas with more medical services. In contrast, the ecology of medical care is easy to evaluate on an isolated island where only primary care is available.

Therefore, we assessed healthcare-seeking behavior on Iheya, an isolated island in Okinawa, Japan. The island has one primary care clinic, one dental office, and one nursing home. There are two public health nurses in the village office, but there are no nurse practitioners/physician assistants/nurse midwives, alternative/complementary medicine facilities, or medical specialists (e.g., optometrists/podiatrists), and the island does not have a pharmacy. Neither surgical facilities nor hospitals with beds are available, and patients requiring advanced care are referred to off-island secondary facilities [15]. A helicopter service is available to transport patients to the main island of Okinawa in medical emergencies.

The present study aimed to describe the ecology of medical care on Iheya, an isolated island where access to secondary care service is limited, and to evaluate the gatekeeping function of the primary care clinic, based on comparison with a previous nationwide survey.