Role of patient factors, preferences, and distrust in health care and access to liver transplantation and organ donation.

Despite major improvements in access to liver transplantation (LT), disparities remain. Little is known about how distrust in medical care, patient preferences, and the origins shaping those preferences contribute to differences surrounding access. We performed a single-center, cross-sectional survey of adults with end-stage liver disease and compared responses between LT listed and nonlisted patients as well as by race. Questionnaires were administered to 109 patients (72 nonlisted; 37 listed) to assess demographics, health care system distrust (HCSD), religiosity, and factors influencing LT and organ donation (OD). We found that neither HCSD nor religiosity explained differences in access to LT in our population. Listed patients attained higher education levels and were more likely to be insured privately. This was also the case for white versus black patients. All patients reported wanting LT if recommended. However, nonlisted patients were significantly less likely to have discussed LT with their physician or to be referred to a transplant center. They were also much less likely to understand the process of LT. Fewer blacks were referred (44.4% versus 69.7%; P = 0.03) or went to the transplant center if referred (44.4% versus 71.1%; P = 0.02). Fewer black patients felt that minorities had as equal access to LT as whites (29.6% versus 57.3%; P < 0.001). For OD, there were more significant differences in preferences by race than listing status. More whites indicated OD status on their driver's license, and more blacks were likely to become an organ donor if approached by someone of the same cultural or ethnic background (P < 0.01). In conclusion, our analysis demonstrates persistent barriers to LT and OD. With improved patient and provider education and communication, many of these disparities could be successfully overcome. Liver Transplantation 22 895-905 2016 AASLD.

Adaptive Brain-Computer Interface Systems For Communication in People with Severe Neuromuscular Disabilities

Brain-computer interfaces (BCI) have the potential to restore communication or control abilities in individuals with severe neuromuscular limitations, such as those with amyotrophic lateral sclerosis (ALS). The role of a BCI is to extract and decode relevant information that conveys a user's intent directly from brain electro-physiological signals and translate this information into executable commands to control external devices. However, the BCI decision-making process is error-prone due to noisy electro-physiological data, representing the classic problem of efficiently transmitting and receiving information via a noisy communication channel.

This research focuses on P300-based BCIs which rely predominantly on event-related potentials (ERP) that are elicited as a function of a user's uncertainty regarding stimulus events, in either an acoustic or a visual oddball recognition task. The P300-based BCI system enables users to communicate messages from a set of choices by selecting a target character or icon that conveys a desired intent or action. P300-based BCIs have been widely researched as a communication alternative, especially in individuals with ALS who represent a target BCI user population. For the P300-based BCI, repeated data measurements are required to enhance the low signal-to-noise ratio of the elicited ERPs embedded in electroencephalography (EEG) data, in order to improve the accuracy of the target character estimation process. As a result, BCIs have relatively slower speeds when compared to other commercial assistive communication devices, and this limits BCI adoption by their target user population. The goal of this research is to develop algorithms that take into account the physical limitations of the target BCI population to improve the efficiency of ERP-based spellers for real-world communication.

In this work, it is hypothesised that building adaptive capabilities into the BCI framework can potentially give the BCI system the flexibility to improve performance by adjusting system parameters in response to changing user inputs. The research in this work addresses three potential areas for improvement within the P300 speller framework: information optimisation, target character estimation and error correction. The visual interface and its operation control the method by which the ERPs are elicited through the presentation of stimulus events. The parameters of the stimulus presentation paradigm can be modified to modulate and enhance the elicited ERPs. A new stimulus presentation paradigm is developed in order to maximise the information content that is presented to the user by tuning stimulus paradigm parameters to positively affect performance. Internally, the BCI system determines the amount of data to collect and the method by which these data are processed to estimate the user's target character. Algorithms that exploit language information are developed to enhance the target character estimation process and to correct erroneous BCI selections. In addition, a new model-based method to predict BCI performance is developed, an approach which is independent of stimulus presentation paradigm and accounts for dynamic data collection. The studies presented in this work provide evidence that the proposed methods for incorporating adaptive strategies in the three areas have the potential to significantly improve BCI communication rates, and the proposed method for predicting BCI performance provides a reliable means to pre-assess BCI performance without extensive online testing.

Factors Impacting Grandparent and Grand Child Communication Across Sex- Related Topics in Kenya

Background: Although many studies have investigated sexual communication between parents and children in Kenya, none have focused singularly on grandparent and grandchild communication when grandparents are primary caregivers. Further, few studies have asked about specific topics related to sex, instead asking generally about “sex related topics” or focusing on HIV/AIDS. This research aims to investigate communication on ten specific sex- related topics between grandparents who are primary caregivers and their grandchildren. The primary research aim was to identify facilitators and barriers to grandparent-grandchild communication associated with frequency of communication. A secondary exploratory question was whether frequency of communication and youth satisfaction with communication were associated with youth’s desire for more communication in the future. Methods: The study was conducted in urban and peri-urban central Kenya. A convenience sample of 193 grandparents and 166 twelve to fifteen year old grandchildren were identified by community health workers. A cross sectional survey assessed nine potential barriers or facilitators to communication (e.g., frequency of communication, perceived grandparent knowledge, grandparent sense of responsibility to communication on a given topic) on ten specified sex- related topics (e.g., peer pressure on sex topics, romantic relationships, condoms). Bivariate and multivariable analyses identified significant associations between communication variables and the outcomes of interest. Results: Bivariate regression showed that higher grandchild age, grandchild gender, higher perceived grandparent knowledge, higher perceived grandparent comfort, higher grandparent-reported sense of responsibility, higher grandparent-reported belief that child should be aware of a given topic before initiating in sex, and higher youth’s own comfort during communication, were significantly associated with higher levels of communication frequency. In the multivariable model, higher grandchild age, gender, higher comfort during communication, and higher perceived grandparent knowledge remained significantly associated with higher levels communication frequency. For the secondary research question, higher communication frequency and higher levels of youth satisfaction were both significantly associated with higher levels of youth desire for more communication in bivariate regression, and higher levels of youth’s satisfaction with communication remained significantly associated with higher levels of youth’s desire for more in the adjusted analysis. Conclusions: This study found that several potential barriers and facilitators of communication are associated with both frequency of and youth’s desire for more communication. The association between grandchild age, gender and perceived grandparent knowledge and frequency of communication is similar to findings from other studies that have examined sex-related communication between parent primary caregivers and children. This finding has important implications for understanding grandparent and grandchild communication, and communication on specific topics in a population from Kenya. The positive association between youth satisfaction of and desire for more communication has important education policy and intervention implications, suggesting that if youth are satisfied with the communication with their caregivers, they may want to learn more.

Health Knowledge, Attitudes, and Practices among Street Children in LMICs

Background: Worldwide, it is estimated that there are up to 150 million street children. Street children are an understudied, vulnerable population. While many studies have characterized street children’s physical health, few have addressed the circumstances and barriers to their utilization of health services.

Methods: A systematic literature review was conducted to understand the barriers and facilitators that street children face when accessing healthcare in low and middle income countries. Six databases were used to search for peer review literature and one database and Google Search engine were used to find grey literature (theses, dissertations, reports, etc.). There were no exclusions based on study design. Studies were eligible for inclusion if the study population included street children, the study location was a low and middle income country defined by the World Bank, AND whose subject pertained to healthcare.

In addition, a cross-sectional study was conducted between May 2015 and August 2015 with the goal of understanding knowledge, attitudes, and health seeking practices of street children residing in Battambang, Cambodia. Time location and purposive sampling were used to recruit community (control) and street children. Both boys and girls between the ages of 10 and 18 were recruited. Data was collected through a verbally administered survey. The knowledge, attitudes and health seeking practices of community and street children were compared to determine potential differences in healthcare utilization.

Results: Of the 2933 abstracts screened for inclusion in the systematic literature review, eleven articles met all the inclusion criteria and were found to be relevant. Cost and perceived stigma appeared to be the largest barriers street children faced when attempting to seek care. Street children preferred to receive care from a hospital. However, negative experiences and mistreatment by health providers deterred children from going there. Instead, street children would often self treat and/or purchase medicine from a pharmacy or drug vendor. Family and peer support were found to be important for facilitating treatment.

The survey found similar results to the systematic review. Forty one community and thirty four street children were included in the analysis. Both community and street children reported the hospital as their top choice for care. When asked if someone went with them to seek care, both community and street children reported that family members, usually mothers, accompanied them. Community and street children both reported perceived stigma. All children had good knowledge of preventative care.

Conclusions: While most current services lack the proper accommodations for street children, there is a great potential to adapt them to better address street children’s needs. Street children need health services that are sensitive to their situation. Subsidies in health service costs or provision of credit may be ways to reduce constraints street children face when deciding to seek healthcare. Health worker education and interventions to reduce stigma are needed to create a positive environment in which street children are admitted and treated for health concerns.

Using Coding to Improve Localization and Backscatter Communication Performance in Low-Power Sensor Networks

Backscatter communication is an emerging wireless technology that recently has gained an increase in attention from both academic and industry circles. The key innovation of the technology is the ability of ultra-low power devices to utilize nearby existing radio signals to communicate. As there is no need to generate their own energetic radio signal, the devices can benefit from a simple design, are very inexpensive and are extremely energy efficient compared with traditional wireless communication. These benefits have made backscatter communication a desirable candidate for distributed wireless sensor network applications with energy constraints.

The backscatter channel presents a unique set of challenges. Unlike a conventional one-way communication (in which the information source is also the energy source), the backscatter channel experiences strong self-interference and spread Doppler clutter that mask the information-bearing (modulated) signal scattered from the device. Both of these sources of interference arise from the scattering of the transmitted signal off of objects, both stationary and moving, in the environment. Additionally, the measurement of the location of the backscatter device is negatively affected by both the clutter and the modulation of the signal return.

This work proposes a channel coding framework for the backscatter channel consisting of a bi-static transmitter/receiver pair and a quasi-cooperative transponder. It proposes to use run-length limited coding to mitigate the background self-interference and spread-Doppler clutter with only a small decrease in communication rate. The proposed method applies to both binary phase-shift keying (BPSK) and quadrature-amplitude modulation (QAM) scheme and provides an increase in rate by up to a factor of two compared with previous methods.

Additionally, this work analyzes the use of frequency modulation and bi-phase waveform coding for the transmitted (interrogating) waveform for high precision range estimation of the transponder location. Compared to previous methods, optimal lower range sidelobes are achieved. Moreover, since both the transmitted (interrogating) waveform coding and transponder communication coding result in instantaneous phase modulation of the signal, cross-interference between localization and communication tasks exists. Phase discriminating algorithm is proposed to make it possible to separate the waveform coding from the communication coding, upon reception, and achieve localization with increased signal energy by up to 3 dB compared with previous reported results.

The joint communication-localization framework also enables a low-complexity receiver design because the same radio is used both for localization and communication.

Simulations comparing the performance of different codes corroborate the theoretical results and offer possible trade-off between information rate and clutter mitigation as well as a trade-off between choice of waveform-channel coding pairs. Experimental results from a brass-board microwave system in an indoor environment are also presented and discussed.

The Perspectives of Gay, Bisexual, and Queer Adolescent Males with Parent-Child Sex Communication

Problem: Gay, bisexual, and queer (GBQ) adolescent males are disproportionately affected by negative sexual health outcomes compared to their heterosexual counterparts. Their sex education needs are not sufficiently addressed in the home and the larger ecological systems. The omission of their sex education needs at a time when they are forming a sexual identity during adolescence compels GBQ males to seek information in unsupervised settings. Evidence-based interventions aimed at ensuring positive sexual health outcomes through sex communication cannot be carried out with these youth as research on how parents and GBQ males discuss sex in the home has been largely uninvestigated.

Methods: This naturalistic qualitative study focused on the interpretive reports of 15- to 20-year-old GBQ males’ discussions about sex-related topics with their parents. From a purposive sample of 30 male adolescents who self-identified as GBQ, participants who could recall at least one conversation about sex with their parents were recruited for one-time interviews and card sorts. This strategy revealed, using Bronfenbrenners’ Bioecological Theory, their perceptions about sex communication in the context of their reciprocal relationship and the ecological systems that GBQ males and their parents navigate.

Results: Parents received poor ratings as sex educators, were generally viewed as not confident in their communication approach, and lacked knowledge about issues pertinent to GBQ sons. Nevertheless, participants viewed parents as their preferred source of sex information and recognized multiple functions of sex communication. The value placed by GBQ youth on sex communication underscores their desire to ensure an uninterrupted parent-child relationship in spite of their GBQ sexual orientation. For GBQ children, inclusive sex communication is a proxy for parental acceptance.

Results show that the timing, prompts, teaching aids, and setting of sex communication for this population are similar to what has been reported with heterosexual samples. However, most GBQ sons rarely had inclusive guidance about sex and sexuality that matched their attraction, behavior, and identities. Furthermore, the assumption of heterosexuality resulted in the early awareness of being different from their peers which led them to covertly search for sex information. The combination of assumed heterosexuality and their early reliance on themselves for applicable information is a missed parental opportunity to positively impact the health of GBQ sons. More importantly, due to the powerful reach of new media, there is a critical period of maximum receptiveness that has been identified which makes inclusive sex communication paramount in the pre-sexual stage for this population. Our findings also indicate that there are plenty of opportunities for systemic improvements to meet this population’s sexual education needs.