NHash: Randomized N-Gram Hashing for Distributed Generation of Validatable Unique Study Identifiers in Multicenter Research

BACKGROUND: A unique study identifier serves as a key for linking research data about a study subject without revealing protected health information in the identifier. While sufficient for single-site and limited-scale studies, the use of common unique study identifiers has several drawbacks for large multicenter studies, where thousands of research participants may be recruited from multiple sites. An important property of study identifiers is error tolerance (or validatable), in that inadvertent editing mistakes during their transmission and use will most likely result in invalid study identifiers. OBJECTIVE: This paper introduces a novel method called Randomized N-gram Hashing (NHash), for generating unique study identifiers in a distributed and validatable fashion, in multicenter research. NHash has a unique set of properties: (1) it is a pseudonym serving the purpose of linking research data about a study participant for research purposes; (2) it can be generated automatically in a completely distributed fashion with virtually no risk for identifier collision; (3) it incorporates a set of cryptographic hash functions based on N-grams, with a combination of additional encryption techniques such as a shift cipher; (d) it is validatable (error tolerant) in the sense that inadvertent edit errors will mostly result in invalid identifiers. METHODS: NHash consists of 2 phases. First, an intermediate string using randomized N-gram hashing is generated. This string consists of a collection of N-gram hashes f1, f2, ..., fk. The input for each function fi has 3 components: a random number r, an integer n, and input data m. The result, fi(r, n, m), is an n-gram of m with a starting position s, which is computed as (r mod |m|), where |m| represents the length of m. The output for Step 1 is the concatenation of the sequence f1(r1, n1, m1), f2(r2, n2, m2), ..., fk(rk, nk, mk). In the second phase, the intermediate string generated in Phase 1 is encrypted using techniques such as shift cipher. The result of the encryption, concatenated with the random number r, is the final NHash study identifier. RESULTS: We performed experiments using a large synthesized dataset comparing NHash with random strings, and demonstrated neglegible probability for collision. We implemented NHash for the Center for SUDEP Research (CSR), a National Institute for Neurological Disorders and Stroke-funded Center Without Walls for Collaborative Research in the Epilepsies. This multicenter collaboration involves 14 institutions across the United States and Europe, bringing together extensive and diverse expertise to understand sudden unexpected death in epilepsy patients (SUDEP). CONCLUSIONS: The CSR Data Repository has successfully used NHash to link deidentified multimodal clinical data collected in participating CSR institutions, meeting all desired objectives of NHash

Selective digestive or oropharyngeal decontamination and topical oropharyngeal chlorhexidine for prevention of death in general intensive care : systematic review and network meta-analysis

Peer reviewedPublisher PD

Addressing the Health Needs of an Aging America: New Opportunities for Evidence-Based Policy Solutions

This report systematically maps research findings to policy proposals intended to improve the health of the elderly. The study identified promising evidence-based policies, like those supporting prevention and care coordination, as well as areas where the research evidence is strong but policy activity is low, such as patient self-management and palliative care. Future work of the Stern Center will focus on these topics as well as long-term care financing, the health care workforce, and the role of family caregivers

Optimizing patient care and outcomes through the congenital heart center of the 21st century

Pediatric cardiovascular services are responding to the dynamic changes in the medical environment, including the business of medicine. The opportunity to advance our pediatric cardiology field through collaboration is now realized, permitting us to define meaningful quality metrics and establish national benchmarks through multicenter efforts. In March 2016, the American College of Cardiology hosted the first Adult Congenital/Pediatric Cardiology Section Congenital Heart Community Day. This was an open participation meeting for clinicians, administrators, patients/parents to propose metrics that optimize patient care and outcomes for a stateâ ofâ theâ art congenital heart center of the 21st century. Care center collaboration helps overcome the barrier of relative small volumes at any given program. Patients and families have become active collaborative partners with care centers in the definition of acute and longitudinal outcomes and our quality metrics. Understanding programmatic metrics that create an environment to provide outstanding congenital heart care will allow centers to improve their structure, processes and ultimately outcomes, leading to an increasing number of centers that provide excellent care. This manuscript provides background, as well listing of proposed specialty domain quality metrics for centers, and thus serves as an updated baseline for the ongoing dynamic process of optimizing care and realizing patient value.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143653/1/chd12575_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143653/2/chd12575.pd

Development and validation of a hospital indicator of resource use intensity for injury admissions

Introduction : Les blessures représentent la 5ème cause d’hospitalisation au Canada. En 2010, leur soins ont couté 16 milliards de dollars. Selon des études Américaines, l’utilisation des ressources en traumatologie n’est pas strictement dictée par l’état des patients. Toutefois, le manque d’outil de mesure et de surveillance de l’intensité d’utilisation des ressources a jusque là empêché le développement d’interventions visant à améliorer l’efficience des soins en traumatologie. Objectifs : Notre objectif général était de développer et valider un indicateur de l’intensité d’utilisation des ressources pour les soins aigus en traumatologie. Nos objectifs spécifiques étaient de (1) faire une synthèse des méthodes d’évaluation des coûts des soins aigus en traumatologie ; (2) estimer l’utilisation des ressources pour les soins aigus en traumatologie, identifier les déterminants de cette utilisation et en évaluer la variation inter-hospitalière et (3) développer un indicateur de l’intensité d’utilisation des ressources pour les soins aigus en traumatologie et en évaluer les validités interne et temporelle. Méthodes : Pour le premier objectif, nous avons effectué une revue systématique de la littérature. Pour les second et troisième objectifs, nous avons mené des études de cohortes ur les personnes de ≥ 16 ans hospitalisées dans les centres de traumatologie pour adultes au Québec, de 2014 à 2016. Nous avons extrait les données du registre des traumatismes et des rapports financiers des hôpitaux et estimé l’utilisation des ressources avec des coûts par centre d’activité hospitalière. Pour le second objectif, nous avons identifié les déterminants avec un modèle linéaire multi-niveau, déterminé leur importance relative avec le coefficient f² de Cohen et évalué la variation avec le coefficient de corrélation intra-classe (CCI) et son intervalle de confiance à 95%. Pour le troisième objectif, nous avons effectué les analyses par niveau de désignation des centres de traumatologie (I/II et III/IV). Nous avons développé des modèles d’ajustement pour tous les patients et pour des groupes diagnostics spécifiques puis évalué les validités interne et temporelle avec respectivement le coefficient de détermination (r²) et le r²) annuel. Résultats : Pour la revue systématique, 10 études étaient éligibles. L’évaluation des hôpitaux était ajustée selon l’état des patients à l’arrivée dans seulement cinq études (50%). Dans la seconde étude (n = 32,411), les plus importantes composantes de l’utilisation des ressources étaient les soins réguliers (57%), le bloc opératoire (23%) et les soins intensifs(13%). Le plus important déterminant était la destination à la sortie de l’hôpital (f² = 7%). La plus grande utilisation des ressources était observée pour les blessures médullaires :11193$(7115-17606) par admission. Alors que l’utilisation des ressources augmentait avec l’âge pour les soins réguliers, elle diminuait avec l’âge pour le bloc opératoire. L’utilisation des ressources était 19$ (Quartiles 1 et 3 : 3045-8762). Nous avons identifié des centres où l’utilisation des ressources était plus grande ou plus petite que la moyenne géométrique provinciale, globalement et pour les blessures cranio-cérébrales, orthopédiques isolées et thoraco-abdominales isolées. Conclusions : Nos données suggèrent que 70% à 90% de l’utilisation des ressources en traumatologie au Québec est dictée par des facteurs autres que le statut clinique des patients. Nous avons développé un indicateur pour identifier les variations de l’utilisation des ressources dans un même centre/système de traumatologie, au fil du temps, ou entre centres/systèmes de traumatologie dans un(e) même province/pays. Cet indicateur ainsi que les déterminants de l’utilisation des ressources que nous avons identifiés peuvent servir de données probantes pour l’allocation des ressources et l’élaboration d’interventions visant à améliorer l’efficience des soins en traumatologie. Présentement, des études examinent l’association entre l’intensité d’utilisation des ressources et les résultats cliniques des patients à partir des méthodes développées dans ce projet. Les études futures devraient identifier les déterminants des variations inter-hospitalières de l’utilisation des ressources.Background: Injuries are the 5th leading cause of hospitalization in Canada and their care cost 16 billion dollars in 2010. Studies in the United States suggest that resource use fo racute injury care may be driven by factors other than the clinical status of patients. However, the lack of tools to measure and monitor resource use intensity has hampered the development of interventions aiming to improve the efficiency of injury care. Objectives: Our goal was to develop and validate a hospital indicator of resource use intensity for injury admissions. Our objectives were to (1) review how data on costs have been used to evaluate injury care; (2) estimate patient-level resource use for injury admissions, identify determinants of resource use intensity, and evaluate inter-hospital variations in resource use; and (3) develop a hospital indicator of resource use intensity fo rinjury admissions, and evaluate its internal and temporal validity. Methods: For the first objective, we conducted a systematic review of the literature. For the second and third objectives, we conducted retrospective, multicenter cohort studies based on ≥ 16-year-olds admitted to adult trauma centers in Quebec from 2014 to 2016. We extracted data from the Quebec trauma registry and hospital financial reports and estimated resource use with activity-based costs. For the second objective, we identified determinants using a multilevel linear model and assessed their relative importance with Cohen’s f² , and evaluated variations with intraclass correlation coefficients (ICC) and 95% confidence intervals. For the third objective, we conducted analyses by trauma center designation level (I/II and III/IV). We developed risk-adjustment models using a competing risks framework for the whole sample and for specific diagnostic groups. We assessed model internal validity with the optimism-corrected coefficient of determination (r² ), and temporal validity with yearly r² . We performed benchmarking by comparing the adjusted geometric mean cost of each center, obtained using shrinkage estimates, to the provincial geometric mean. Results: In our systematic review, we identified 10 eligible studies, of which nine were conducted in the United States. Hospital comparisons were adjusted according to patient case mix in only five studies (50%). In our second study (n = 32,411), activity centers associated with the greatest resource use were the regular ward (57%), followed by the operating room (23%) and the intensive care unit (13%). The strongest determinant of resource use was discharge destination (f² = 7%). Among injury types, the highest resource use was observed for spinal cord injuries: $11,193 (7115-17,606) per admission. While resource use increased with increasing age for the regular ward, it decreased with increasing age for the operating room. Resource use was 19$5014 (Quartiles 1 and 3: 3045-8762). In the whole sample and among patients with traumatic brain, isolated orthopedic and isolated thoracoabdominal injuries, we identified centers with higher or lower than expected resource use. Conclusions: Our review highlighted the need for more data on trauma center resource use, particularly in single-payer healthcare systems. Results from our second and third studies suggest that between 70% and 90% of the variation in resource use for injury care in Quebec is dictated by factors other than the clinical status of patients on arrival. We developed an indicator to identify variations in resource use intensity within a single trauma center or system over time, or across provinces or countries. This indicator and the determinants of resource use intensity we identified can be used to establish evidence-based resource allocations and design high-impact interventions to improve the efficiency of acute injury care. Research is underway to examine the association between hospital resource use intensity and clinical outcomes for trauma patients based on the methods we developed. Future research should identify determinants of inter-hospital variations inresource use intensity and aspects of resource use that drive optimal patient outcomes