One-way Travel Time Research Articles

Residential areas, travel burdens, and children with cancer: Analysis of mobility and mortality ratios using data from Japan's national population-based cancer registry

Objectives Although childhood cancer treatment has recently become centralized at specialized hospitals worldwide, the relationship between mortality ratios and living in rural areas or traveling long distances for treatment remains controversial. In the present study, we examined whether regional differences in patient mobility and mortality ratios exist in Japan.Methods We investigated 10,713 patients with cancer aged ≤18 years, diagnosed between 2016 and 2019, registered in the national cancer registry data. The patients were divided into two categories based on their residence at diagnosis: urban and rural. Urban areas were defined as metropolitan or urban areas according to the 2015 census or as prefectural cities; all other areas were defined as rural. Additionally, we divided the patients into two groups based on the one-way travel time to the treatment hospital (≤1 h or >1 h), as estimated from location information at the community level using route-planner web services. Next, we calculated the percentage of patients who received treatment within their residences in both areas and for each treatment type. We compared the percentage of distant metastasis in all cancers and each diagnosis group between the two areas using the chi-square test. We finally applied Cox proportional hazard models to obtain adjusted mortality hazard ratios for urban versus rural areas and travel times of ≤1 h versus >1 h.Results Overall, 77% of the patients were classified as urban residents. The percentages of patients receiving treatment within their residency, secondary medical care area, prefecture, and regional block levels were 22-46%, 80-87%, and 95-99%, respectively. Only central nervous system tumors (III) showed a significant difference in the percentage of distant metastases, which were more common in urban areas (6% vs. 3%). The adjusted mortality hazard ratios were not significantly different between urban and rural areas for all cancers or each diagnosis group. The travel time comparison yielded significant differences of 1.17 for all cancers and 2.57 for lymphomas (II).Conclusion Approximately 80% of the patients received treatment within their prefecture, although a few traveled long distances across regional blocks. We observed no differences in the mortality ratio between urban and rural areas, although significant differences were found in all cancers and one cancer in the travel burden comparison. These results highlight the need for continued evaluation of the increasing trend in patient travel burden and its impact on survival, as childhood cancer treatment has become centralized in Japan.

An adaptive MAC-agnostic ranging scheme for underwater acoustic mobile networks

In the last ten years several simulation studies on Autonomous Underwater Vehicle (AUV) swarm fleet formation have been performed, and some preliminary sea demonstrations of proof-of-concept prototypes were carried out. However, their actual realization is hindered by the challenges imposed by the underwater acoustic channel and the difficulties of keeping track of the vehicles’ positions due to the long latency required by traditional Two-Way Travel-Time (TWTT) ranging measurements, that require a specific signaling, hence limiting the throughput of the underwater network. Although One-Way Travel-Time (OWTT) halves the latency, it requires a high precision oscillator, such as an atomic clock or an oven controlled crystal oscillator (OCXO), to be installed in each modem processing unit: while atomic clocks are still very expensive, OCXO are very power demanding, making their application to underwater acoustic networks not always possible, especially in the case of low cost vehicle swarms.In this paper we present a network protocol stack able to perform ranging and localization within the communication task in underwater acoustic networks, limiting the network overhead. Specifically, new layers have been added to the preexisting DESERT Underwater protocol stack to perform the ranging tasks without compromising the correct operation of the communication network. A ranging layer is placed on top of the Medium Access Control (MAC) scheme, allowing the latter to be changed according to the network topology and requirements. This MAC-agnostic ranging layer is further optimized by adapting the amount of data transmitted according to the channel state, and the ranging entries inserted in the data packets according to the least recent information transmitted, hence minimizing the Age of Information. Simulation results obtained with the DESERT Underwater Framework show how this layer allows all AUVs in the swarm to know their distance from every other node in the network, thus limiting the probability of vehicle collisions and allowing better mission coordination.

Telemedicine for Multidisciplinary Urologic Cancer Care: A Prospective Single Institution Study

BackgroundWe rapidly implemented a telemedicine Multidisciplinary Urologic Cancer Clinic (MDUCC) at the University of Washington/Seattle Cancer Care Alliance during the peak of the COVID-19 Public Health Emergency to maintain our ability to provide multidisciplinary cancer care. We report our experiences though assessment of patient-reported outcomes from our telemedicine MDUCC. MethodsVideo visits with a urologic oncologist, medical oncologist, and radiation oncologist were conducted in the same format as our in-person MDUCC. We prospectively collected patient demographic and clinical data. Patients were invited to complete a post-visit survey that assessed satisfaction, provider trust, travel time, and costs of the telemedicine visit. We estimated travel distances and times from each patient's home to our clinic. ResultsAmong invited patients, twenty-four patients completed a survey after their telemedicine MDUCC visit. Twenty patients (83%) were at home during the visit. Most (85%) were men, Caucasian (79%), and were being seen in our Bladder Cancer MDUCC (83%). All twenty-four patients responded that they would be willing to have future appointments via telemedicine; eighteen patients (75%) strongly agreed that the encounter was high quality; 19 patients strongly agreed that they were satisfied with their visit. Patients saved an estimated average one-way travel distance of 145 miles and one-way travel time of 179 minutes to convene a telemedicine visit. ConclusionsTelemedicine MDUCCs are feasible and effective in providing access to multidisciplinary urologic cancer care. Patient satisfaction was high, and many patients were spared a substantial travel burden. Telemedicine may continue to be leveraged to improve access to multidisciplinary urologic cancer care.

Characterizing the Traveling Oncology Workforce and Its Influence on Patient Travel Burden: A Claims-Based Approach.

Oncology outreach is a common strategy for extending cancer care to rural patients. However, a nationwide characterization of the traveling workforce that enables this outreach is lacking, and the extent to which outreach reduces travel burden for rural patients is unknown. This cross-sectional study analyzed a rural (nonurban) subset of a 100% fee-for-service sample of 355,139 Medicare beneficiaries with incident breast, colorectal, and lung cancers. Surgical, medical, and radiation oncologists were linked to patients using Part B claims, and traveling oncologists were identified by observing hospital service area (HSA) transition patterns. We defined oncology outreach as the provision of cancer care by a traveling oncologist outside of their primary HSA. We used hierarchical gamma regression models to examine the separate associations between patient receipt of oncology outreach and one-way patient travel times to chemotherapy, radiotherapy, and surgery. On average, 9,935 of 39,960 oncologists conducted annual outreach, where 57.8% traveled with low frequency (0-1 outreach visits/mo), 21.1% with medium frequency (1-3 outreach visits/mo), and 21.1% with high frequency (>3 outreach visits/mo). Oncologists provided surgery, radiotherapy, and chemotherapy to 51,715, 27,120, and 5,874 rural beneficiaries, respectively, of whom 2.5%, 6.9%, and 3.6% received oncology outreach. Rural patients who received oncology outreach traveled 16% (95% CI, 11 to 21) and 11% (95% CI, 9 to 13) less minutes to chemotherapy and radiotherapy than those who did not receive oncology outreach, corresponding to expected one-way savings of 15.9 (95% CI, 15.5 to 16.4) and 11.9 (95% CI, 11.7 to 12.2) minutes, respectively. Our study introduces a novel claims-based approach for tracking the nationwide traveling oncology workforce and supports oncology outreach as an effective means for improving rural access to cancer care.

Advanced Electric Propulsion Concepts for Fast Missions to the Outer Solar System and Beyond

Electric Propulsion (EP) comprises all types of space propulsion in which a certain amount of propellant is ionized and then accelerated by electric or magnetic fields, or both. This propulsion technology allows for much higher specific impulses (Isp > 2,000 s) than conventional chemical propulsion (Isp < 500 s), resulting in a major reduction of the propellant mass or a considerably higher final speed for a certain space mission. Hence, EP can enable very challenging space missions as DAWN has clearly shown. Furthermore, an EP system coupled with an advanced nuclear reactor could enable fast manned missions to Mars (one-way travel times less than 4 months). This propulsion technology can be scaled up to even higher specific impulses (Isp > 5,000s). However, the power needed for the same thrust is also increasing. An Oberth maneuver performed very close to the Sun could provide the additional power to a high-Isp Solar Electric Propulsion (SEP) system in order to reach the needed delta-v for challenging interstellar precursor missions. A breakthrough in power source specific mass is needed in order to enable missions with ultra-high specific impulses (> 10,000 s); this breakthrough could be realized having the power source not on board, as with Laser-powered Electric Propulsion (LEP), where the needed power is beamed to the spacecraft from an external laser source. In this case the on-board power source is limited to a light-weight photovoltaic receiver/converter. The development of ultra-high Isp ion thrusters powered by an external laser source could enable the most challenging interstellar precursor missions up to the Oort Cloud and beyond. This paper gives an update on the status of these advanced propulsion concepts, and provides some examples of interstellar precursor missions enabled by advanced EP systems which could be launched before 2040. Keywords: Interstellar, Electric Propulsion, Oberth, Laser

Applications of telemedicine: Plastic surgery in the COVID-19 era

Applications of telemedicine: Plastic surgery in the COVID-19 era

Routing Optimization of Regional Flexible Transit Under the Mixed Demand Mode

To meet trip demands and avoid transit capacity waste or shortages, this study investigates the routing optimization of flexible transit with time windows. We introduce the time penalty costs to accommodate the impacts of early and late vehicle arrivals on passengers’ satisfaction. A routing optimization model is developed to minimize the system operation costs and the costs incurred by passengers' time penalties. The problem is solved by a designed adaptive genetic algorithm that adopts an adaptive mutation strategy to dynamically adjust the mutation probability and mutation operator. The numerical experiments compare the results of the mixed demand model, in which vehicles can pick up and drop off passengers simultaneously, to those of the separate pick-up and delivery modes. Finally, a sensitive analysis is conducted to explore the impact of operational factors (vehicle speed, maximum one-way travel time, and weighting ratios between operating and penalty costs) on the system's performance (total costs, per capita mileage, and average seat occupancy rate). Our results confirm the advantages of the developed adaptive genetic algorithm over traditional ones with respect to the convergence speed and optimality gap. Moreover, the numerical results indicate that the mixed demand operation mode of transit reduces total costs by an average of 2.35% compared to separate pick-up and delivery modes. The results also reveal that an increase in the weights of the operating cost can reduce the total cost. The findings of this work can provide guidance to the operation of regional flexible transit.

Tightly Coupled INS/APS Passive Single Beacon Navigation

Unlike aerial or terrestrial navigation, the global navigation satellite system (GNSS) is not available underwater. This is a big challenge for underwater navigation. The inertial navigation system (INS) aided by the single-beacon acoustic positioning system (APS) provides one solution, but the long-range case is limited by low-SNR conditions. Inspired by passive synthetic aperture detection, we proposed a new tightly coupled navigation algorithm based on spatial synthesis and one-way-travel-time (OWTT) range measurement. We design two estimators: the DOA/range estimator using the model-based method and the tightly coupled INS/APS navigation estimator. Based on the improved UKF, all information is combined. Simulation is carried out in MATLAB. Compared with range-only tightly coupled INS/APS navigation, synthetic long baseline (SLBL) algorithm and Doppler velocity logger (DVL) aided centralized extended Kalman filter (CEKF) based single beacon INS/OWTT navigation, the proposed method’s performance is proven. The main contributions of this work are: (1). Propose a new architecture of underwater integrated navigation; (2). Apply the passive acoustic detecting method in the navigation to improve accuracy. (3). Apply the tightly coupled method to improve availability.

A Software-Defined Underwater Acoustic Modem for Everyone: Design and Evaluation

The development of small low-cost autonomous underwater and surface vehicles has increased the need for underwater wireless communication and ranging to support swarm operations for collaborative data collection efforts. Specifically, newly available low-cost underwater and surface vehicles make the realization of swarm formation cost effective. However, their mission coordination involves the use of expensive acoustic modems whose price may be higher than that of the vehicle itself. In this paper, we describe and evaluate a low-cost software-defined acoustic modem developed with only off-the-shelf components, able to perform one-way travel-time ranging. The modem is specifically designed for dense mobile networks deployed in shallow water environments, such as rivers, lagoons and lakes. The modular software design of the modem allows us to easily configure parameters such as modulation and coding schemes, scheduling algorithm, source power, carrier frequency and bandwidth. In this paper we evaluate, in a shallow environment, the modem performance in terms of packet detection ratio, packet delivery ratio, and one-way travel-time ranging.

PTA-Sync: Packet-Train-Aided Time Synchronization for Underwater Acoustic Applications

In underwater acoustic applications, time synchronization errors accumulate severely with time, owing to the unpredictable propagation delay change induced by mobility and low sound propagation speed. In previously reported schemes, error accumulation during underwater acoustic time synchronization occurred, decreasing their performance and affecting their applicability. To overcome this limitation, we propose packet-train-aided time synchronization (PTA-Sync) for underwater acoustic application. The proposed PTA-Sync adaptively tracks one-way travel time (OWTT) change using three-dimensional linear velocity vector, the transmit time difference and arrival time difference of two adjacent packets in a packet train, and the position information of a mobile reference node. Thus, this scheme enables us to reduce the synchronization error accumulation rate by estimating the propagation delay change more accurately. Simulation results show PTA-Sync achieves higher accuracy than existing OWTT-based synchronization schemes. Thus, PTA-Sync can be effectively used in underwater exploratory activities because it can successfully reduce time synchronization errors.

A high‐resolution AUV navigation framework with integrated communication and tracking for under‐ice deployments

AbstractWe developed an environmentally adaptive under‐ice navigation framework that was deployed in the Arctic Beaufort Sea during the United States Navy Ice Exercise in March 2020 (ICEX20). This navigation framework contained two subsystems developed from the ground up: (1) an on‐board hydrodynamic model‐aided navigation (HydroMAN) engine, and (2) an environmentally and acoustically adaptive integrated communication and navigation network (ICNN) that provided acoustic navigation aiding to the former. The HydroMAN synthesized measurements from an inertial navigation system (INS), ice‐tracking Doppler velocity log (DVL), ICNN and pressure sensor into its self‐calibrating vehicle flight dynamic model to compute the navigation solution. The ICNN system, which consisted of four ice buoys outfitted with acoustic modems, trilaterated the vehicle position using the one‐way‐travel‐times (OWTT) of acoustic datagrams transmitted by the autonomous underwater vehicle (AUV) and received by the ice buoy network. The ICNN digested salinity and temperature information to provide model‐assisted real‐time OWTT range conversion to deliver accurate acoustic navigation updates to the HydroMAN. To decouple the contributions from the HydroMAN and ICNN subsystems towards a stable navigation solution, this article evaluates them separately: (1) HydroMAN was compared against DVL bottom‐track aided INS during pre‐ICEX20 engineering trials where both systems provided similar accuracy; (2) ICNN was evaluated by conducting a static experiment in the Arctic where the ICNN navigation updates were compared against GPS with ICNN error within low tens of meters. The joint HydroMAN‐ICNN framework was tested during ICEX20, which provided a nondiverging high‐resolution navigation solution—with the majority of error below 15 m—that facilitated a successful AUV recovery through a small ice hole after an 11 km untethered run in the upper and mid‐water column.

Passive Inverted Ultra-Short Baseline Positioning for a Disc-Shaped Autonomous Underwater Vehicle: Design and Field Experiments

Underwater positioning is critical to autonomous underwater vehicles (AUVs) for navigation and geo-referencing. The rapid attenuation of the electromagnetic wave in the underwater environment prevents the use of traditional positioning methods such as the Global Positioning System, whereupon acoustic methods like ultra-short baseline (USBL) positioning systems play an important role in AUV navigation. However, the high cost and complexity of classical USBL systems have stifled the democratization of these technologies, which leads to a new method called passive inverted ultra-short baseline (piUSBL) positioning. In a typical piUSBL system, a single beacon is placed at a reference point, periodically broadcasting a positioning signal. A passive USBL receiver, time-synchronized to the beacon, is mounted on an AUV to get one-way travel-time (OWTT) slant range and azimuth estimates. The passive nature of the receiver means the system is inexpensive, low-power, and lightweight. Particularly, the omnidirectional broadcasted signals offer a feasible solution for concurrent multi-AUV navigation. This letter demonstrates a full-stack design and development of a piUSBL positioning system, and presents evaluations of the accuracy and reliability of the system through a series of experiments. More significantly, a successful sea trial of a disc-shaped AUV outfitted with our piUSBL was conducted in the South China Sea.

Synchronous-Clock Range-Angle Relative Acoustic Navigation: A Unified Approach to Multi-AUV Localization, Command, Control, and Coordination

This paper presents a scalable acoustic navigation approach for the unified command, control, and coordination of multiple autonomous underwater vehicles (AUVs). Existing multi-AUV operations typically achieve coordination manually by programming individual vehicles on the surface via radio communications, which becomes impractical with large vehicle numbers; or they require bi-directional intervehicle acoustic communications to achieve limited coordination when submerged, with limited scalability due to the physical properties of the acoustic channel. Our approach utilizes a single, periodically broadcasting beacon acting as a navigation reference for the group of AUVs, each of which carries a chip-scale atomic clock and fixed ultrashort baseline array of acoustic receivers. One-way travel-time from synchronized clocks and time-delays between signals received by each array element allow any number of vehicles within receive distance to determine range, angle, and thus determine their relative position to the beacon. The operator can command different vehicle behaviors by selecting between broadcast signals from a predetermined set, while coordination between AUVs is achieved without intervehicle communication by defining individual vehicle behaviors within the context of the group. Vehicle behaviors are designed within a beacon-centric moving frame of reference, allowing the operator to control the absolute position of the AUV group by repositioning the navigation beacon to survey the area of interest. Multiple deployments with a fleet of three miniature, low-cost SandShark AUVs performing closed-loop acoustic navigation in real-time provide experimental results validated against a secondary long-baseline positioning system, demonstrating the capabilities and robustness of our approach with real-world data.

A precise underwater positioning method by considering the location difference of transmitting and receiving sound waves

To improve the underwater positioning precision of the traditional underwater positioning method that only uses one-way sound propagation, the paper proposes a new underwater positioning method by considering the location difference between transmission and reception of sound waves in circle-sailing positioning. In the method, firstly a fast calculation of the incidence angles was given under the depth constraint. And then, a precise positioning method was put forward by correcting the one-way travel time and considering the process of transmitting and receiving sound waves to double the observations to improve the underwater positioning precision. Two data sets observing the identical transponder were used to test the validity. The experiments verified the proposed method and the results showed that the precision of underwater positioning was improved considerably, especially in the vertical direction. The proposed method achieved the more uniform horizontal locations than the traditional method.

Design and experimental results of passive iUSBL for small AUV navigation

This paper presents a passive inverted Ultra-Short Baseline (piUSBL) positioning system which provides accurate and instantaneous positioning for small Autonomous Underwater Vehicles (AUVs) at low cost and power consumption. Conventional underwater positioning systems tend to be expensive and bulky, limiting the application of small AUVs. This system is based on an iUSBL positioning system, which places a small circular receiver array on an AUV rather than on a deployment ship. The One-Way Travel-Time (OWTT) range and Direction of Arrival (DOA) between the vehicle and a single acoustic beacon enable AUV navigation relative to the beacon. Deconvolved conventional beamforming (dCv) provides high-resolution azimuth estimation. This paper describes the system design in detail and presents experimental results in an anechoic tank and some field lakes. The piUSBL system shows great potential for small AUVs after several successful AUV applications.

UKF-Based Inverted Ultra-Short Baseline SLAM With Current Compensation

This paper presents an inverted ultra-short baseline (iUSBL) simultaneous localization and mapping (SLAM) based on Unscented Kalman filter (UKF) with current compensation. The complexity of the underwater environment prevents the use of Global Positioning System (GPS) or visible-light cameras, thereby we rely on an acoustic positioning system to achieve autonomous underwater vehicle (AUV) navigation relative to the beacons. Our system considers using an AUV equipped with a time-synchronized iUSBL array to measure the range and angle between vehicle and acoustic beacons via one-way travel-time. Then, we propose UKF-based online SLAM to filter these acoustic measurements, meanwhile, add current compensation which is inherent underwater. In contrast, traditional SLAM applications usually contain a large number of landmarks, this iUSBL acoustic system only needs sparse beacons to estimate the vehicle pose. Consequently, it does not cause UKF to have an excessive computational burden. The validity of the proposed method is confirmed by numerical results. In particular, the proposed algorithm prevents cumulative errors from growing quickly quite well when using double beacons.

Continuously sensing of water temperature in a lake using acoustic tomography method

ABSTRACT Continuously sensing of water temperature is of critical importance to water environment, fluid dynamic and water resources researches. Coastal acoustic tomography (CAT) is a remote sensing technique in spatial temperature distribution estimating and has been widely used in many coastal regions. Continuous observations of water temperature in small-scale waters with distance less than 1 km are seldom conducted, as it is difficult to get high-resolution observation results. Here, a horizontal temperature field within 300 m distance was mapped in a sound transmission experiment with three 50 kHz CAT systems. The maximum inversion error temperature for the horizontal temperature field was 0.09°C. The root-mean-square error between the CAT-observed and range-averaged temperature that were calculated from one-way travel time data along three transmission paths were 0.03°C, 0.028°C and 0.043°C, respectively. The obtained results confirmed that CAT can be used in recovering the horizontal distributions of water temperature fields in lake.

Abstract 67: Quantifying Transportation Barriers in Rwandan Patients Seeking Treatment for Breast Cancer

Abstract Purpose: Comprehensive cancer care in many sub-Saharan African countries is concentrated within a few centers. With only two comprehensive treatment facilities in Rwanda, travel distance, travel time, and travel cost may represent underappreciated barriers to accessing cancer treatment. Here we describe travel and transportation experiences of patients receiving curative breast cancer treatment at Butaro Cancer Center of Excellence (BCCOE). Methods: A cross-sectional telephone survey assessing contributors of care-continuum delays was administered to female patients receiving curative breast cancer treatment. Between July and November 2020, 89 (75%) of eligible patients were reached by phone, all of whom provided verbal consent and voluntarily participation. Patient demographic information and transportation experience were descriptively summarized. Results Participants had a median age of 48 years, and they represented all five Rwandan provinces. Twenty-one patients (24%) belonged to the lowest of the four socioeconomic “ubudehe” strata, as defined by the local government, while none were in the highest stratum. Few patients' households owned transportation vehicles with only one owning a private car, 4 (4%) owning a motorbike, and 23 (26%) owning a bicycle. Most patients, 84 (94%) utilized public transport buses for a portion of their travel, while 48 (54%) utilized motorbikes. Median one-way travel time from patients' home to BCCOE was 7 hours (interquartile range: 6-8 hours). The median cost of transportation for each round-trip was RWF12000, approximately $12 USD, which equates to 75% of a Rwandan adult's total monthly consumption. Transportation costs were noted as a significant barrier by 43 patients (46%), and 35 (39%) received financial support from outside their household to pay for transportation. Conclusion Transportation time and cost are significant burdens on patients receiving breast cancer treatment in Rwanda. Studies are needed to evaluate strategies for alleviating these burdens, such as comprehensive transportation financial support and innovative care delivery with telemedicine. Citation Format: Temidayo Fadelu, Cam Nguyen, Nicaise Nsabimana, Evariste Bigirimana, Vestine Mukandayisenga, Hubert Tuyishime, Lawrence Shulman, Timothy Rebbeck. Quantifying Transportation Barriers in Rwandan Patients Seeking Treatment for Breast Cancer [abstract]. In: Proceedings of the 9th Annual Symposium on Global Cancer Research; Global Cancer Research and Control: Looking Back and Charting a Path Forward; 2021 Mar 10-11. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2021;30(7 Suppl):Abstract nr 67.

Tele-TB: Using TeleMedicine to Increase Access to Directly Observed Therapy for Latent Tuberculosis Infection.

Treatment of latent tuberculosis infection (LTBI) decreases risk of progression to active tuberculosis. Traditional treatment regimens required either daily isoniazid for 9 months, with historically poor compliance, or 12-week directly observed therapy (DOT) with isoniazid and rifapentine, with improved compliance but additional challenges of coordinating weekly clinic visits, further complicated if patients must travel a great distance for care. Our referral area is complicated by congested traffic often resulting in one-way commutes, which can exceed 2 hours. These travel times would be prohibitive for conducting weekly in-clinic DOT. In an effort to improve access to DOT, we implemented TeleMedicine LTBI DOT (vDOT) within a military pediatric infectious diseases clinic. Patients aged 24 months or older diagnosed with LTBI were referred for possible enrollment into our vDOT clinic. All patients without contraindications for receiving isoniazid and/or rifapentine were offered LTBI treatment via weekly vDOT or daily treatment with isoniazid or rifampin. The first visit for vDOT patients was performed in person to discuss treatment options, demonstrate use of TeleMedicine software, and ensure the patient was able to take the medications. Baseline information about patients and travel time to our facility was determined. To date, 16 patients have completed LTBI therapy using vDOT. Average one-way travel time to our facility for patients was 51 minutes. Actual time spent in most vDOT encounters was less than 10 minutes. Appointments were arranged to take place outside usual school and work hours so patients could complete vDOT with minimal interruptions to daily life, resulting in 100% treatment compliance and completion. Conducting LTBI DOT using TeleMedicine is a viable and time-saving measure that still allows for high levels of patient compliance and treatment completion while minimizing interruptions to academic and work schedules.

Identifying Food Deserts and People with Low Food Access, and Disparities in Dietary Habits and Health in Korea

This study aims to identify the regions and people with low food access (LFA) for Korea at the national level and to examine disparities in food consumption, dietary behavior, and health outcome for those regions and people. Based on the distance to the nearest grocery store from residence, the regions and people with LFA are identified through geographical information system (GIS) analysis. To examine disparities between the regions and people with LFA and without LFA, a consumer survey is conducted and data from National Health and Nutrition Examination Survey and Community Health Survey are analyzed. This study found that there exists a serious access to food issue in Korea, especially for the aged. Moreover, there also exist significant disparities between the regions and people with and without LFA in the distance and one-way travel time to the grocery store that is mainly visited, frequency of offline/online grocery shopping, availability of various foods, dietary habits such as eating regularly, eating nutritionally balanced foods, and eating sufficient fruit/vegetable/whole grains, the acquisition and utilization of food-related information, and health outcomes. This study suggests that, to resolve such a serious food access problem, assistance policies, such as mobile grocery stores and lunch-box delivery, need to be activated in countries similar to Korea since this problem could potentially deteriorate the national medical finances as well as the regional and individual disparities.