Hardness of Computing and Approximating Predicates and Functions with Leaderless Population Protocols

Population protocols are a distributed computing model appropriate for describing massive numbers of agents with very limited computational power (finite automata in this paper), such as sensor networks or programmable chemical reaction networks in synthetic biology. A population protocol is said to require a leader if every valid initial configuration contains a single agent in a special "leader" state that helps to coordinate the computation. Although the class of predicates and functions computable with probability 1 (stable computation) is the same whether a leader is required or not (semilinear functions and predicates), it is not known whether a leader is necessary for fast computation. Due to the large number of agents n (synthetic molecular systems routinely have trillions of molecules), efficient population protocols are generally defined as those computing in polylogarithmic in n (parallel) time. We consider population protocols that start in leaderless initial configurations, and the computation is regarded finished when the population protocol reaches a configuration from which a different output is no longer reachable. In this setting we show that a wide class of functions and predicates computable by population protocols are not efficiently computable (they require at least linear time), nor are some linear functions even efficiently approximable. It requires at least linear time for a population protocol even to approximate division by a constant or subtraction (or any linear function with a coefficient outside of N), in the sense that for sufficiently small gamma > 0, the output of a sublinear time protocol can stabilize outside the interval f(m) (1 +/- gamma) on infinitely many inputs m. In a complementary positive result, we show that with a sufficiently large value of gamma, a population protocol can approximate any linear f with nonnegative rational coefficients, within approximation factor gamma, in O(log n) time. We also show that it requires linear time to exactly compute a wide range of semilinear functions (e.g., f(m)=m if m is even and 2m if m is odd) and predicates (e.g., parity, equality)

Efficient size estimation and impossibility of termination in uniform dense population protocols

We study uniform population protocols: networks of anonymous agents whose pairwise interactions are chosen at random, where each agent uses an identical transition algorithm that does not depend on the population size $n$. Many existing polylog$(n)$ time protocols for leader election and majority computation are nonuniform: to operate correctly, they require all agents to be initialized with an approximate estimate of $n$ (specifically, the exact value $\lfloor \log n \rfloor$). Our first main result is a uniform protocol for calculating $\log(n) \pm O(1)$ with high probability in $O(\log^2 n)$ time and $O(\log^4 n)$ states ($O(\log \log n)$ bits of memory). The protocol is converging but not terminating: it does not signal when the estimate is close to the true value of $\log n$. If it could be made terminating, this would allow composition with protocols, such as those for leader election or majority, that require a size estimate initially, to make them uniform (though with a small probability of failure). We do show how our main protocol can be indirectly composed with others in a simple and elegant way, based on the leaderless phase clock, demonstrating that those protocols can in fact be made uniform. However, our second main result implies that the protocol cannot be made terminating, a consequence of a much stronger result: a uniform protocol for any task requiring more than constant time cannot be terminating even with probability bounded above 0, if infinitely many initial configurations are dense: any state present initially occupies $\Omega(n)$ agents. (In particular, no leader is allowed.) Crucially, the result holds no matter the memory or time permitted. Finally, we show that with an initial leader, our size-estimation protocol can be made terminating with high probability, with the same asymptotic time and space bounds.Comment: Using leaderless phase cloc

Patient experience and challenges in group concept mapping for clinical research.

BACKGROUND AND OBJECTIVE: Group concept mapping (GCM) is a research method that engages stakeholders in generating, structuring and representing ideas around a specific topic or question. GCM has been used with patients to answer questions related to health and disease but little is known about the patient experience as a participant in the process. This paper explores the patient experience participating in GCM as assessed with direct observation and surveys of participants. METHODS: This is a secondary analysis performed within a larger study in which 3 GCM iterations were performed to engage patients in identifying patient-important outcomes for diabetes care. Researchers tracked the frequency and type of assistance required by each participant to complete the sorting and rating steps of GCM. In addition, a 17-question patient experience survey was administered over the telephone to the participants after they had completed the GCM process. Survey questions asked about the personal impact of participating in GCM and the ease of various steps of the GCM process. RESULTS: Researchers helped patients 92 times during the 3 GCM iterations, most commonly to address software and computer literacy issues, but also with the sorting phase itself. Of the 52 GCM participants, 40 completed the post-GCM survey. Respondents averaged 56 years of age, were 50% female and had an average hemoglobin A1c of 9.1%. Ninety-two percent (n = 37) of respondents felt that they had contributed something important to this research project and 90% (n = 36) agreed or strongly agreed that their efforts would help others with diabetes. Respondents reported that the brainstorming session was less difficult when compared with sorting and rating of statements. DISCUSSION: Our results suggest that patients find value in participating in GCM. Patients reported less comfort with the sorting step of GCM when compared with brainstorming, an observation that correlates with our observations from the GCM sessions. Researchers should consider using paper sorting methods and objective measures of sorting quality when using GCM in patient-engaged research to improve the patient experience and concept map quality

Examining the Role of Diagnosis in the Emergency Department Experience

Study Objective: To explore the social, functional, and emotional needs that patients want addressed when seeking a diagnosis at their ED visit.https://jdc.jefferson.edu/cwicposters/1037/thumbnail.jp

Once I Take that One Bite : the Consideration of Harm Reduction as a Strategy to Support Dietary Change for Patients with Diabetes

BACKGROUND: Despite well-established guidelines to treat diabetes, many people with diabetes struggle to manage their disease. For many, this struggle is related to challenges achieving nutrition-related lifestyle changes. We examined how people with diabetes describe barriers to maintaining a healthy diet and considered the benefits of using a harm reduction approach to assist patients to achieve nutrition-related goals. METHODS: This is a secondary analysis of 89 interviews conducted with adults who had type 1 or type 2 diabetes. Interviews were analyzed using a content analysis approach. Themes regarding food or diet were initially captured in a food node. Data in the food node were then sub-coded for this analysis, again using a content analysis approach. RESULTS: Participants frequently used addiction language to talk about their relationship with food, at times referring to themselves as an addict and describing food as their drug. Participants perceived their unhealthy food choices either as a sign of weakness or as cheating. They also identified food\u27s ability to comfort them and an unwillingness to change as particular challenges to sustaining a healthier diet. CONCLUSION: Participants often described their relationship with food through an addiction lens. A harm reduction approach has been associated with positive outcomes among those with substance abuse disorder. Patient-centered communication incorporating the harm reduction model may improve the patient-clinician relationship and thus improve patient outcomes and quality-of-life while reducing health-related stigma in diabetes care. Future work should explore the effectiveness of this approach in patients with diabetes. TRIAL REGISTRATION: Registered on ClinicalTrials.gov, NCT02792777. Registration information submitted 02/06/2016, with the registration first posted on the ClinicalTrials.gov website 08/06/2016. Data collection began on 29/04/2016

Developing standardized patient-based cases for communication training: lessons learned from training residents to communicate diagnostic uncertainty.

Health professions education has benefitted from standardized patient (SP) programs to develop and refine communication and interpersonal skills in trainees. Effective case design is essential to ensure an SP encounter successfully meets learning objectives that are focused on communication skills. Creative, well-designed case scenarios offer learners the opportunity to engage in complex patient encounters, while challenging them to address the personal and emotional contexts in which their patients are situated. Therefore, prior to considering the practical execution of the patient encounter, educators will first need a clear and structured strategy for writing, organizing, and developing cases. The authors reflect on lessons learned in developing standardized patient-based cases to train learners to communicate to patients during times of diagnostic uncertainty, and provide suggestions to develop a set of simulation cases that are both standardized and diverse. Key steps and workflow processes that can assist educators with case design are introduced. The authors review the need to increase awareness of and mitigate existing norms and implicit biases, while maximizing variation in patient diversity. Opportunities to leverage the breadth of emotional dispositions of the SP and the affective domain of a clinical encounter are also discussed as a means to guide future case development and maximize the value of a case for its respective learning outcomes

I had no other choice but to catch it too : the roles of family history and experiences with diabetes in illness representations.

BACKGROUND: A family history of diabetes and family members\u27 experiences with diabetes may influence individuals\u27 beliefs and expectations about their own diabetes. No qualitative studies have explored the relationship between family history and experiences and individuals\u27 diabetes illness representations. METHODS: Secondary data analysis of 89 exploratory, semi-structured interviews with adults with type 1 or type 2 diabetes seeking care in an urban health system. Participants had a recent diabetes-related ED visit/hospitalization or hemoglobin A1c \u3e 7.5%. Interviews were conducted until thematic saturation was achieved. Demographic data were collected via self-report and electronic medical record review. Interviews were audio-recorded, transcribed, and coded using a conventional content analysis approach. References to family history and family members\u27 experiences with diabetes were analyzed using selected domains of Leventhal\u27s Common Sense Model of Self-Regulation. RESULTS: Participants cited both genetic and behavioral family history as a major cause of their diabetes. Stories of relatives\u27 diabetes complications and death figured prominently in their discussion of consequences; however, participants felt controllability over diabetes through diet, physical activity, and other self-care behaviors. CONCLUSIONS: Findings supported an important role of family diabetes history and experience in development of diabetes illness representations. Further research is needed to expand our understanding of the relationships between these perceptions, self-management behaviors, and outcomes. Family practice providers, diabetes educators and other team members should consider expanding assessment of current family structure and support to also include an exploration of family history with diabetes, including which family members had diabetes, their self-care behaviors, and their outcomes, and how this history fits into the patient\u27s illness representations

Emergency Medicine Clinician Experiences Addressing Uncertainty in First-Trimester Bleeding.

The purpose of this work is to understand Emergency Department (ED) clinicians\u27 experiences in communicating uncertainty about first-trimester bleeding (FTB) and their need for training on this topic. This cross-sectional study surveyed a national sample of attending physicians and advanced practice providers (APPs). The survey included quantitative and qualitative questions about communicating with patients presenting with FTB. These questions assessed clinicians\u27 frequency encountering challenges, comfort, training, prior experience, and interest in training on the topic. Of 402 respondents, 54% reported that they encountered challenges at least sometimes when discussing FTB with patients where the pregnancy outcome is uncertain. While the majority (84%) were at least somewhat prepared for these conversations from their training, which commonly addressed the diagnostic approach to this scenario, 39% strongly or moderately agreed that they could benefit from training on the topic. Because the majority of ED clinicians identified at least sometimes encountering challenges communicating with pregnant patients about FTB, our study indicates a need exists for more training in this skill

Development of the Uncertainty Communication Checklist: A Patient-Centered Approach to Patient Discharge From the Emergency Department

Clear communication with patients upon emergency department (ED) discharge is important for patient safety during the transition to outpatient care. Over one-third of patients are discharged from the ED with diagnostic uncertainty, yet there is no established approach for effective discharge communication in this scenario. From 2017 to 2019, the authors developed the Uncertainty Communication Checklist for use in simulation-based training and assessment of emergency physician communication skills when discharging patients with diagnostic uncertainty. This development process followed the established 12-step Checklist Development Checklist framework and integrated patient feedback into 6 of the 12 steps. Patient input was included as it has potential to improve patient-centeredness of checklists related to assessment of clinical performance. Focus group patient participants from 2 clinical sites were included: Thomas Jefferson University Hospital, Philadelphia, PA, and Northwestern University Hospital, Chicago, Illinois. The authors developed a preliminary instrument based on existing checklists, clinical experience, literature review, and input from an expert panel comprising health care professionals and patient advocates. They then refined the instrument based on feedback from 2 waves of patient focus groups, resulting in a final 21-item checklist. The checklist items assess if uncertainty was addressed in each step of the discharge communication, including the following major categories: introduction, test results/ED summary, no/uncertain diagnosis, next steps/follow-up, home care, reasons to return, and general communication skills. Patient input influenced both what items were included and the wording of items in the final checklist. This patient-centered, systematic approach to checklist development is built upon the rigor of the Checklist Development Checklist and provides an illustration of how to integrate patient feedback into the design of assessment tools when appropriate

I Don\u27t Have a Diagnosis for You: Preparing Medical Students to Communicate Diagnostic Uncertainty in the Emergency Department

Introduction: Diagnostic uncertainty abounds in medicine, and communication of that uncertainty is critical to the delivery of high-quality patient care. While there has been training in communicating diagnostic uncertainty directed towards residents, a gap remains in preparing medical students to understand and communicate diagnostic uncertainty. We developed a session to introduce medical students to diagnostic uncertainty and to practice communicating uncertainty using a checklist during role-play patient conversations. Methods: This virtual session was conducted for third-year medical students at the conclusion of their core clerkships. It consisted of prework, didactic lecture, peer role-play, and debriefing. The prework included reflection prompts and an interactive online module. The role-play featured a patient complaining of abdominal pain being discharged from the emergency department without a confirmed diagnosis. Students participated in the role of patient, provider, or observer. Results: Data from an anonymous postsession survey (76% response rate; 202 of 265 students) indicated that most students (82%; 152 of 185) felt more comfortable communicating diagnostic uncertainty after the session. A majority (83%; 166 of 201) indicated the session was useful, and most (81%; 149 of 184) indicated it should be included in the curriculum. Discussion: This virtual session requires few facilitators; has peer role-play, eliminating the need for standardized patients; and is adaptable for in-person teaching. As its goal was to introduce an approach to communicating diagnostic uncertainty, not achieve mastery, students were not individually assessed for proficiency using the Uncertainty Communication Checklist. Students felt the session intervention was valuable