Wei et al. International Journal for Equity in Health (2017) 16:206 DOI 10.1186/s12939-017-0702-z RESEARCH Open Access Evaluating medical convenience in ethnic minority areas of Southwest China via road network vulnerability: a case study for Dehong autonomous prefecture Xiaoyan Wei1,2,3,4,5, Xuejun Liu1,2,3*, Liang Cheng6,7,8,9*, Lele Sun10, Yingying Pan4,5 and Wenwen Zong9 Abstract Background: Southwest China is home to more than 30 ethnic minority groups. Since most of these populations reside in mountainous areas, convenient access to medical services is an important metric of how well their livelihoods are being protected. Methods: This paper proposes a medical convenience index (MCI) and computation model for mountain residents, taking into account various conditions including topography, geology, and climate. Data on road networks were used for comprehensive evaluation from three perspectives: vulnerability, complexity, and accessibility. The model is innovative for considering road network vulnerability in mountainous areas, and proposing a method of evaluating road network vulnerability by measuring the impacts of debris flows based on only links. The model was used to compute and rank the respective MCIs for settlements of each ethnic population in the Dehong Dai and Jingpo Autonomous Prefecture of Yunnan Province, in 2009 and 2015. Data on the settlements over the two periods were also used to analyze the spatial differentiation of medical convenience levels within the study area. Results: The medical convenience levels of many settlements improved significantly. 80 settlements were greatly improved, while another 103 showed slight improvement.Areas with obvious improvement were distributed in clusters, and mainly located in the southwestern part of Yingjiang County, northern Longchuan County, eastern Lianghe County, and the region where Lianghe and Longchuan counties and Mang City intersect. Conclusions: Development of the road network was found to be a major contributor to improvements in MCI for mountain residents over the six-year period. Keywords: Ethnic minority areas, Medical convenience, Road network, Vulnerability, Mountainous areas Background border areas [1, 2]. People from all 55 groups can be China has 55 different ethnic minority groups in found in Southwest China, where their numbers amount addition to the Han Chinese. These groups are mainly to 35.55 million, accounting for 31% of China’s total located in eight of the country’s central and western ethnic minority population. This region hosts 30 ethnic provinces: Xinjiang, Qinghai, Tibet, Yunnan, Guizhou, minority groups with populations exceeding 5000 each. Inner Mongolia, Guangxi, and Ningxia. Most ethnic Some of these groups are unique and indigenous to the minorities live in remote mountainous areas, deserts, or region. Southwest China, centered on the Yunnan–Gui- zhou Plateau, has the highest global distribution density * Correspondence: [email protected]; [email protected] of ethnic minorities. 1Key Laboratory of Virtual Geographic Environment (Nanjing Normal The southwestern region of China is situated at the University), Ministry of Education, Nanjing 210023, China junction of the Eurasian, Indian, and Pacific tectonic 6Collaborative Innovation Center for the South Sea Studies, Nanjing University, Nanjing, China plates. The topography here is rugged and, it is one of Full list of author information is available at the end of the article the world’s steepest and most remote regions. The © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Wei et al. International Journal for Equity in Health (2017) 16:206 Page 2 of 16 forbidding and complex terrains can present extreme in- distance is commonly used because the requisite data convenience for everyday activities [3]. Access to basic are easily available, the calculation method is simple, medical and healthcare services has been recognized as and the results are readily understood [6–11]. “a basic right of the people” [4]. Medical convenience In recent years, the most widely used method for level is closely related to the lives and safety of ethnic studying medical accessibility and the balance between minorities. It reflects the public service capacity in ethnic the demand and supply of medical and healthcare minority areas, and is an important assurance for main- facilities is floating catchment area (FCA), and associated taining unity and stability in those areas. Therefore, it is enhancements such as the two-step floating catchment very important and necessary to evaluate medical conveni- area (2SFCA) method, enhanced two-step floating catch- ence in ethnic minority areas of Southwest China. ment area (E2SFCA) method and the three-step floating The total area of Southwest China is about 2.35 mil- catchment area (2SFCA) method. FCA originated from lions square kilometers, where 19.8 million people live. spatial decomposition [12], and is a special case of grav- According to China’s Health and Family Planning Statis- ity model [13]. The application and improvement of this tical Yearbook (2015), there are totally 2153 first-class method made calculations simpler and the results more and above hospitals in mountain areas of Southwest rational [5, 6, 14–20]. Methods used in other studies in- China, which mainly distribute in urban regions. In this cluded the gravity model [6, 16, 21] and kernel density region, the hospitals are very rare at remote mountain estimation (KDE) [20, 22, 23]. Neutens (2015) [24] fur- areas and the distances from some settlements to a hos- ther analyzed the advantages and disadvantages of the pital are very long. Roads in mountain areas are highly aforementioned methods when studying medical accessi- vulnerable and complex, which are easily affected by bility. However, there remains a lack of research on road topography and debris flow. It is difficult and inconveni- network vulnerability and its impact on residents’ ent for residents in some remote mountainous regions medical convenience levels. to go to those hospitals. Despite numerous studies on road network vulnerabil- Aiming to the medical convenience evaluation, this study ity in the past two decades, the concept of vulnerability focuses on road network analysis within ethnic minority has yet to be clearly defined. It is often jointly explained areas, since the construction and development of road net- with other related terms such as risk, reliability, flexibil- works is one of the most important factors affecting med- ity, robustness, and resilience. Many scholars have also ical convenience levels among ethnic minority attempted to explore the inter-relationships between communities in mountainous areas. Medical convenience those terms [25–28]. A review of the literature indicated index (MCI) and evaluation models are proposed from that research on road network vulnerability generally three perspectives: vulnerability, complexity, and accessibil- adopts one of the following perspectives: ity. In 2012, in order to gain a comprehensive understand- ing of China’s current geographical conditions and meet the i. The connectivity of the road network, taking into need of social and economic development and ecological account its topological structure. For example, civilization construction, the State Council of China re- Kurauchi et al. (2009) [29] determined the critical leased a notification to conduct the First Survey of National index of each road segment by calculating the Geographical Conditions, also called the first China Geog- number of connecting links between journey origin raphy Census (CGC), from 2013 to 2015. The CGC has and destination, thereby identifying critical segments two aspects of contents:(1)to survey the attributes of nature in the road network. Rupi et al. (2015)[30]evaluated geographical factors, including the type, site, scope, area of the vulnerability of mountain road networks by topography, vegetation cover, water area, desert, open examining the connectivity between start and end ground, and etc..(2)to survey the attributes of human geo- points, before grading them. graphical factors, including the classification, site and scope ii. After a segment has deteriorated, the road network of transport network, settlements, geography units, and becomes disrupted or its traffic capacity declines. etc., which are closelyrelatedto human activities. The census This reduces regional accessibility and leads to provides the most authoritative, objective, and accurate socioeconomic losses. These losses are used to geographical data for the present study. determine and grade critical segments of the road network. For example, Jenelius et al. (2006) [27] Related work ranked the importance of different roads based on Current studies by Chinese and international scholars their daily traffic volumes. Next, the impact of each on medical and healthcare services for residents mostly road grading on traveling options and durations focus on accessibility