Date Published: March 4, 2019
Publisher: Public Library of Science
Author(s): Kenta Okuyama, Kenju Akai, Tsunetaka Kijima, Takafumi Abe, Minoru Isomura, Toru Nabika, Antonio Palazón-Bru.
Although primary care access is known to be an important factor when seeking care, its effect on individual health risk has not been evaluated by an appropriate spatial measure. This study examined whether geographic accessibility to primary care assessed by a sophisticated form of spatial measure is associated with a risk of hypertension and its treatment status among Japanese people in rural areas, where primary care is not yet established as specialization. We used an enhanced two-step floating catchment area method to calculate the neighborhood residential unit-level primary and secondary care accessibility for 52,029 subjects who participated in the 2015 annual health checkup held at 15 cities in Shimane Prefecture. Their hypertension level and treatment status were examined cross-sectionally with their neighborhood primary care and secondary care accessibility (computed with two separate distance-decay weight: slow and quick) by multivariable logistic regression controlling for demographics and neighborhood income level. The findings showed that greater geographic accessibility to primary care was associated with a decreased risk of hypertension in both slow and quick distance-decay weight, odds ratio (OR) = 0.989 (95% Confidence Interval (CI) = 0.984, 0.994), OR = 0.989 (95%CI = 0.984, 0.993), respectively. On the other hand, better secondary care accessibility was associated with an increased risk of hypertension and untreated hypertension; however, the effect of secondary care was mitigated by the effect of primary care accessibility in both slow and quick distance-decay model, hypertension: OR = 0.974 (95% CI = 0.957, 0.991), OR = 0.981 (95%CI = 0.970, 0.991), untreated hypertension: OR = 0.970 (95%CI = 0.944, 0.996), OR = 0.975 (95%CI = 0.959, 0.991), respectively.
Access to care is an important factor that determines the health of the overall population . Easy access to care is known to lower mortality and morbidity [2, 3], and primary care services function to reduce burdens on patients in terms of time and cost while offering appropriate treatments, thereby improving the health of the population . Despite evidence that emphasizes the importance of primary care for population health, primary care is not yet well-established in Japan. The Organization for Economic Co-operation and Development (OECD) evaluated the quality of the Japanese healthcare system in 2015. Though the OECD’s evaluation noted the reputedly-long life expectancy of the Japanese population, it also pointed out that compared to other OECD countries, Japanese people experience considerably longer hospital stays and higher healthcare expenditures. The report indicated that the lack of a distinct primary care specialty is one reason, and it is critical for a rapidly aging population in which a preventive and holistic approach to healthcare is needed . Primary care in Japan is provided by semi-generalists/semi-specialists who have been working as generalists in the community with unspecified amount of time to train as generalists after they left hospital practice. On the other hand, generalists in Europe are required to complete specialized training in family medicine, and primary care is recognized as a distinct medical specialty. Access to care, which is an important principle of primary care, consists of multiple domains: approachability, acceptability, availability and accommodation, affordability, and appropriateness [1, 6]. Availability, which entails geographic accessibility, is crucial, especially in rural settings. However, healthcare resources, including both facilities and physicians, are unequally distributed across regions; this remains a significant issue globally [7, 8]. In Japan, though unequal access to healthcare resources and regional health disparity are among the major public health problems, studies on geographic accessibility to healthcare are fairly limited .
The geocoding process resulted in locating 52,029 subjects in a total of 1210 Chou Aza units. The E2FCA scores for primary and secondary care facilities with slow and quick distance-decay were assigned for each sample according to their residential units (Figs 4–7). Tables 1 and 2 show the basic characteristics of study samples by hypertension and untreated hypertension statuses. There were 14,369 (27.6%) subjects who had hypertension (Table 1). There were significantly more males (vs. females), smokers (vs. non-smokers), and drinkers (vs. non-drinkers) among those with hypertension than those without hypertension. Age and BMI were higher among those with hypertension than those without hypertension. Neighborhood mean income was significantly lower among those with hypertension than those without hypertension. Accessibility (E2FCA score) to primary and secondary care were significantly higher among those with hypertension than those without hypertension for both slow and quick distance-decay. Among people with hypertension, 6693 (46.6%) subjects had untreated hypertension (Table 2). There were significantly more males (vs. females), smokers (vs. non-smokers), and drinkers (vs. non-drinkers) among those with untreated hypertension than those with treated hypertension. Age and BMI were lower among those with untreated hypertension than those with treated hypertension. Neighborhood mean income was significantly lower among those with untreated hypertension than those with treated hypertension. E2FCA scores for primary care were significantly lower among those with untreated hypertension than those with treated hypertension for both slow and quick distance-decay. On the contrary, E2FCA scores for secondary care were higher among those with untreated hypertension than those with treated hypertension.
In our study, we aimed to assess the association between hypertension status as well as treatment status and geographic accessibility to primary and secondary care facilities. The results indicate that geographic accessibility to primary care is important for workers in Shimane Prefecture in terms of both hypertension and treatment status. On the contrary, geographic accessibility to secondary care facilities was found to be associated with an increased risk of having hypertension and untreated hypertension. However, the model with the interaction term for primary and secondary care accessibility showed that the multiplicative effect of primary and secondary care accessibility decreased the risk of hypertension and untreated hypertension. The interaction could be interpreted as the effect of primary care accessibility was modified by secondary care accessibility, or vice versa. Theoretically, the effect of primary care accessibility may have mitigated the effect of secondary care accessibility as the hypertensive condition as well as treatment status are assumed to be affected by easy access to care but not expensive specialized care. Primary care facilities in Japan are usually open on weekends, while secondary care facilities generally are not and typically do not accept initial visits for hypertension except on weekday mornings. Therefore, when only secondary care is available close by, it may not increase the likelihood of workers seeking care unless they take extra time off, which rarely happens. However, greater access to primary care alone did not result in improved status for hypertension treatment. This may be because primary care service has not been fully established yet in Japan; thus, it might not be widely accepted and known of by the communities and residents. In addition, access to care is not determined by only geographic accessibility, but also aspects of care quality, such as continuity of care, physicians’ communication skills, and waiting time. These components could not be assessed in this study, and it could have overlooked some effect of primary care access on hypertension treatment status.
In conclusion, geographic accessibility to primary care facilities was important for hypertension and untreated hypertension. In order to achieve health equity by establishing and maintaining equal accessibility to healthcare, it is essential to assess healthcare accessibility with appropriate spatial measures, consider its association with individual health risks, and gain region- and culture-specific perspectives.