Linkage Process Research Articles

Centralized access to cancer registries

PurposeThe U.S. Food and Drug Administration and National Cancer Institute are seeking to improve methods to evaluate cancer as a clinical outcome in postapproval studies of drug and device safety. Challenges to monitoring cancer outcomes include years-long latency periods for many cancers, difficulty in tracking patients over long periods of time, missing outcomes of interest if relying on reporting by patients or health care providers, burden of collecting high-quality, detailed documentation of incident cancers, and low statistical power for rarer cancers. MethodsRegistration of incident cancers including patient identifiers occurs in every U.S. state. Yet, each state cancer registry is administered and must be accessed separately, which creates a nearly insurmountable burden of time, effort, and cost for postmarket surveillance in multiple or all states. A voluntary process is in development which would allow states to reduce these barriers and enhance the health and safety of their residents. Called the Virtual Pooled Registry–Cancer Linkage System, state cancer registries will continue to hold and control their registry data while having access to a more streamlined process for postmarket surveillance, providing better quality, complete, and more rapid discovery. ResultsA Web-based application and review process are in development with an additional effort devoted to highly automated linkage processes and federally compliant data file transmission security. ConclusionsThe Food and Drug Administration and National Cancer Institute will have enhanced abilities to perform high-quality postmarket surveillance and other research at lower cost and with faster speed. This system also seeks to reduce cost and burden by participating state cancer registries. This process also supports the current modifications proposed by the U.S. Department of Health and Human Services and 15 other Federal Departments and Agencies to modernize, strengthen, and make more effective the Federal Policy for the Protection of Human Subjects known as the Common Rule.

Effects of void band orientation and crystallographic anisotropy on void growth and coalescence

The effects of void band orientation and crystallographic anisotropy on void growth and linkage have been investigated. 2D model materials were fabricated by laser drilling a band of holes into the gage section of sheet tensile samples using various orientation angles with respect to the tensile axis normal. Both copper and magnesium sheets have been studied in order to examine the role of crystallographic anisotropy on the void growth and linkage processes. The samples were pulled in uniaxial tension inside the chamber of an SEM, enabling a quantitative assessment of the growth and linkage processes. The void band orientation angle has a significant impact on the growth and linkage of the holes in copper. As the void band orientation angle is increased from 0° to 45°, the processes of coalescence and linkage are delayed to higher strain values. Furthermore, the mechanism of linkage changes from internal necking to one dominated by shear localization. In contrast, the void band orientation does not have a significant impact on the void growth and linkage processes in magnesium. Void growth in these materials occurs non-uniformly due to interactions between the holes and the microstructure. The heterogeneous nature of deformation in magnesium makes it difficult to apply a coalescence criterion based on the void dimensions. Furthermore, the strain at failure does not show a relationship with the void band orientation angle. Failure associated with twin and grain boundaries interrupts the plastic growth of the holes and causes rapid fracture. Therefore, the impact of the local microstructure outweighs the effects of the void band orientation angle in this material.

On the Effect of Thread Turn Profile Angle of the Planetary Roller-Screw Mechanism Parts on Their Basic Parameters

One of the most important trends in mechanical engineering development is the constant improvement of load capacity of machines, mechanisms, units and parts without increasing their overall dimensions and weight. This is also true for today’s most prospective planetary rollerscrew mechanisms (PRSM) converting motion from rotary to linear type. The problem of PRSM load capacity improvement deserves more attention, because these mechanisms have very high performance characteristics, which leads to problems in the choice of support devices for these mechanisms. However, for many mechanical engineering industries it is important to decrease the PRSMs weight and dimensions, or to improve their reliability and durability. This has led to finding the reserves for improving the PRSM load capacity by decreasing the thread turn profile angle, α, of PRSM threaded parts, as compared to α = 90° in traditional mechanisms. When PRSM calculation methods were developed, it was decided to use α = 90° for transforming the mechanism parts into a physical model and a design pattern. It allowed us to reduce the PRSM designing to well-known roller bearing designing based on very extensive experimental data. Proposed PRSM designs do not contradict to accepted physical models and design patterns – they just have different basic characteristics of PRSM, i.e. static and dynamic load ratings. Proposed PRSM designs with a thread turn profile angle α=70° on their parts allow to increase the load capacity by 15%, as compared to traditional PRSMs, which have threaded parts with a thread turn profile angle α = 90°. There are two factors, which can improve the PRSM load capacity. The first one is the decrease of normal force between mating thread turns of a screw and a roller with the same operational axial force. The second one is the increase of the radius of the shaped profile of a roller thread turn resulting in the expansion of the contact area pattern between the mating thread turns of a screw and a roller. The first factor dominates here. For implementing the proposed PRSM designs into production, one has to explore additionally the effect of α-angle on linkage parameters, process requirements and specific features of the initial contact between the mating thread turns of a screw and a roller.

Effects of void fraction on void growth and linkage in commercially pure magnesium

Void growth and linkage in magnesium is strongly influenced by the local microstructure. An innovative approach is used which allows for a quantitative analysis of the microstructural features that play a significant role in the deformation and fracture processes. Several hole configurations were investigated in order to determine the effects of void fraction on the growth and linkage processes. The samples were pulled in uniaxial tension under both an optical microscope and SEM. The digital image correlation method was used to obtain strain distributions. Furthermore, the experimental results were compared to crystal plasticity finite element simulations in order to determine the role of the various deformation mechanisms on the fracture behavior. It was established that the void fraction did not have a significant impact on the growth and linkage behavior of the holes. Interactions between the holes and the microstructure were observed for all of the configurations analyzed. The strain distributions revealed that twin and grain boundaries produce strain concentrations an order of magnitude larger than the macroscopic strain. Furthermore, the results show that there is likely a critical strain required to initiate fracture in these boundaries.

Impact of microstructure on void growth and linkage in pure magnesium

The role of the microstructure on void growth and linkage in magnesium has been investigated. 2D model materials have been fabricated using pico-second laser technology whereby holes were drilled into the gage section of tensile samples composed of thin Mg sheet. These were pulled in uniaxial tension inside the chamber of an SEM which allowed for a quantitative assessment of the void growth and linkage processes. In contrast to the recent studies of void growth and linkage in fcc metals (copper and aluminum), the local microstructure plays a significant role on the deformation and fracture behavior of magnesium. Void growth was observed to occur non-uniformly due to interactions between the holes and microstructural features such as grain and twin boundaries. In addition, the main fracture mechanisms responsible for void linkage include failure associated with these boundaries. Twin and grain boundaries introduce microstructural features on a length scale comparable to the holes which are not present in models based on continuum mechanics. In order to model the deformation and fracture of magnesium, the initial microstructure as well as microstructural evolution must be taken into account.

Community-engaged strategies to promote hepatitis B testing and linkage to care in immigrants of Florida

To improve early identification and linkage to treatment and preventive services for hepatitis B virus (HBV) in persons born in countries with intermediate or high (>2%) HBV prevalence, the University of Florida Center for HIV/AIDS Research, Education, and Services (UF CARES) employed community-engaged strategies to implement the Hepatitis B Awareness and Service Linkage (HBASL) program. In this brief report, we present a summary of program components, challenges, and successes. Faith and community-based networks were established to improve HBV testing and screening and to increase foreign born nationals (FBNs) access to HBV care. A total of 1516 FBNs were tested and screened for hepatitis B. The majority were females (50.4%), Asians (62.8%), non-Hispanic (87.2%), and they also received post-test counseling (54.8%). Noted program advantages included the development of community networks and outreach to a large population of FBNs. The major challenges were institutional delays, pressures related to meeting program deliverables, and diversity within FBNs populations. Community health workers in the United States can replicate this program in their respective communities and ensure success by maintaining a strong community presence, establishing partnerships and linkage processes, developing a sustainability plan, and ensuring the presence of dedicated program staff.

Evaluation of a Binary Semi-supervised Classification Technique for Probabilistic Record Linkage.

The process of merging data of different data sources is referred to as record linkage. A medical environment with increased preconditions on privacy protection demands the transformation of clear-text attributes like first name or date of birth into one-way encrypted pseudonyms. When performing an automated or privacy preserving record linkage there might be the need of a binary classification deciding whether two records should be classified as the same entity. The classification is the final of the four main phases of the record linkage process: Preprocessing, indexing, matching and classification. The choice of binary classification techniques in dependence of project specifications in particular data quality has not extensively been studied yet. The aim of this work is the introduction and evaluation of an automatable semi-supervised binary classification system applied within the field of record linkage capable of competing or even surpassing advanced automated techniques of the domain of unsupervised classification. This work describes the rationale leading to the model and the final implementation of an automatable semi-supervised binary classification system and the comparison of its classification performance to an advanced active learning approach out of the domain of unsupervised learning. The performance of both systems has been measured on a broad variety of artificial test sets (n = 400), based on real patient data, with distinct and unique characteristics. While the classification performance for both methods measured as F-measure was relatively close on test sets with maximum defined data quality, 0.996 for semi-supervised classification, 0.993 for unsupervised classification, it incrementally diverged for test sets of worse data quality dropping to 0.964 for semi-supervised classification and 0.803 for unsupervised classification. Aside from supplying a viable model for semi-supervised classification for automated probabilistic record linkage, the tests conducted on a large amount of test sets suggest that semi-supervised techniques might generally be capable of outperforming unsupervised techniques especially on data with lower levels of data quality.

Are all metal-on-metal hip revision operations contributing to the National Joint Registry implant survival curves?

AimsThe National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records. MethodsWe analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included.ResultsWe were able to link 716 (77.1%) revision procedures on the NJR to the LIRC. This meant that 213 (22.9%) revision procedures at the LIRC could not be identified on the NJR. We found that 349 (37.6%) explants at the LIRC completed the full linkage process to both NJR primary and revision databases. Data completion was excellent (> 99.9%) for revision procedures reported to the NJR.DiscussionThis study has shown that only approximately one third of retrieved components at the LIRC, contributed to survival curves on the NJR. We recommend prospective registry-retrieval linkage as a tool to feedback missing and erroneous data to the NJR and improve data quality.Take home message: Prospective Registry – retrieval linkage is a simple tool to evaluate and improve data quality on the NJR.Cite this article: Bone Joint J 2016;98-B:33–9.

The acceptability of conducting data linkage research without obtaining consent: lay people's views and justifications.

BackgroundA key ethical issue arising in data linkage research relates to consent requirements. Patients’ consent preferences in the context of health research have been explored but their consent preferences regarding data linkage specifically have been under-explored. In addition, the views on data linkage are often those of patient groups. As a result, little is known about lay people’s views and their preferences about consent requirements in the context of data linkage. This study explores lay people’s views and justifications regarding the acceptability of conducting data linkage research without obtaining consent.MethodsA qualitative study explored lay people’s views regarding consent requirements in data linkage via four hypothetical data linkage scenarios of increasing complexity. Prior to considering the scenarios, participants were provided with information regarding best practice data linkage processes via discussion and a diagrammatic representation of the process.ResultsLay people were able to understand the intricate processes involved in data linkage and the key protections afforded within a short amount of time. They were supportive of data linkage research and, on the whole, believed it should be conducted without consent provided a data linkage organization de-identifies the data used so that researchers do not handle identifiable data. Many thought that de-identified data holds a different status to identifiable data and should be used without specific consent in research that aims to benefit society. In weighing up conflicting values and interests, participants shifted consent preferences before arriving at their final consent preference for each scenario and provided justifications for their choices. They considered the protection of people’s information, societal benefits, and the nature and constraints of research and recognized that these need to be balanced.ConclusionsWith some exposure to the features of data linkage, lay people have the capacity to understand the processes sufficiently in order to consider ethical issues associated with consent preferences. Shifts in views reveal the complexity of such decisions. While privacy protection remained an important consideration for most participants, adequate protection measures adopted in best practice data linkage were viewed by most as protection enough for data linkage to proceed without specific individual consent.

Setting up a regional health system database for seamless population health management in Singapore

Objective: Understanding the health and health service utilization of the population is critical for Regional Health System’s (RHS) population health management (PHM) initiatives in Singapore. The RHS database is a collaborative effort toward developing a national architecture for healthcare utilization data across diverse clinical systems with disparate data models. This manuscript describes the setup of an RHS database which would facilitate big data analytics for proactive population health management and health services research. Materials and methods: The RHS database is a conglomeration of four isolated databases from the three RHSs. It contains linked National Healthcare Group (NHG) polyclinic visit records, specialist outpatient clinic visit records, hospital discharge records from Tan Tock Seng Hospital (TTSH), National University Hospital (NUH) and Alexandra Hospital (AH), chronic disease management system (CDMS) records and mortality records from local registries. The data linkage process was conducted using the unique identification number (NRIC) as the linking variable. The final anonymized database has multiple interconnected tables that includes patient demographics, chronic disease and healthcare utilization information. Results: Over 2.8 million patients had contact with the three RHSs from 2008 to 2013. The database facilitated risk stratification of patients based on their past healthcare utilization and chronic disease information. This database aids in understanding the cross-utilization of healthcare services across the three RHSs and can help address the challenges of setting up a distinct geographical boundary for individual RHSs. Conclusions: The RHS database has been established with the intention to support the secondary use of administrative health data in health services research and proactive PHM in Singapore.

Integrating Brazilian health information systems in order to support the building of data warehouses

IntroductionThis paper's aim is to develop a data warehouse from the integration of the files of three Brazilian health information systems concerned with the production of ambulatory and hospital procedures for cancer care, and cancer mortality. These systems do not have a unique patient identification, which makes their integration difficult even within a single system.MethodsData from the Brazilian Public Hospital Information System (SIH-SUS), the Oncology Module for the Outpatient Information System (APAC-ONCO) and the Mortality Information System (SIM) for the State of Rio de Janeiro, in the period from January 2000 to December 2004 were used. Each of the systems has the monthly data production compiled in dbase files (dbf). All the files pertaining to the same system were then read into a corresponding table in a MySQL Server 5.1. The SIH-SUS and APAC-ONCO tables were linked internally and with one another through record linkage methods. The APAC-ONCO table was linked to the SIM table. Afterwards a data warehouse was built using Pentaho and the MySQL database management system.ResultsThe sensitivities and specificities of the linkage processes were above 95% and close to 100% respectively. The data warehouse provided several analytical views that are accessed through the Pentaho Schema Workbench.ConclusionThis study presented a proposal for the integration of Brazilian Health Systems to support the building of data warehouses and provide information beyond those currently available with the individual systems.

Accuracy of Probabilistic Linkage Using the Enhanced Matching System for Public Health and Epidemiological Studies.

BackgroundThe Enhanced Matching System (EMS) is a probabilistic record linkage program developed by the tuberculosis section at Public Health England to match data for individuals across two datasets. This paper outlines how EMS works and investigates its accuracy for linkage across public health datasets.MethodsEMS is a configurable Microsoft SQL Server database program. To examine the accuracy of EMS, two public health databases were matched using National Health Service (NHS) numbers as a gold standard unique identifier. Probabilistic linkage was then performed on the same two datasets without inclusion of NHS number. Sensitivity analyses were carried out to examine the effect of varying matching process parameters.ResultsExact matching using NHS number between two datasets (containing 5931 and 1759 records) identified 1071 matched pairs. EMS probabilistic linkage identified 1068 record pairs. The sensitivity of probabilistic linkage was calculated as 99.5% (95%CI: 98.9, 99.8), specificity 100.0% (95%CI: 99.9, 100.0), positive predictive value 99.8% (95%CI: 99.3, 100.0), and negative predictive value 99.9% (95%CI: 99.8, 100.0). Probabilistic matching was most accurate when including address variables and using the automatically generated threshold for determining links with manual review.ConclusionWith the establishment of national electronic datasets across health and social care, EMS enables previously unanswerable research questions to be tackled with confidence in the accuracy of the linkage process. In scenarios where a small sample is being matched into a very large database (such as national records of hospital attendance) then, compared to results presented in this analysis, the positive predictive value or sensitivity may drop according to the prevalence of matches between databases. Despite this possible limitation, probabilistic linkage has great potential to be used where exact matching using a common identifier is not possible, including in low-income settings, and for vulnerable groups such as homeless populations, where the absence of unique identifiers and lower data quality has historically hindered the ability to identify individuals across datasets.

Are Birth Certificate and Hospital Discharge Linkages Performed in 52 Jurisdictions in the United States?

The purpose of this study was to determine the number and characteristics of US State Registrars of Vital Statistics (Vital Registrars) and State Systems Development Initiative (SSDI) Coordinators that link birth certificate and hospital discharge data as well as using linkage processes. Vital Registrars and SSDI Coordinators in all 52 vital records jurisdictions (50 states, District of Columbia, and New York City) were asked to complete a 41-question survey. We examined frequency distributions among completed surveys using SAS 9.3. The response rate was 100% (N = 52) for Vital Registrars and 96% (N = 50) for SSDI Coordinators. Nearly half of Vital Registrars (n = 22) and SSDI Coordinators (n = 23) reported that their jurisdiction linked birth certificate and hospital discharge records at least once in the last 4 years. Among those who link, the majority of Vital Registrars (77.3%) and SSDI Coordinators (82.6) link both maternal and infant hospital discharge records to the birth certificate. Of those who do not link, 43% of the Vital Registrars and 55% of SSDI Coordinators reported an interest in linking birth certificate and hospital discharge data. Reasons for not linking included lack of staff time, inability to access raw data, high cost, and unavailability of personal identifiers to link the two sources. Results of our analysis provide a national perspective on data linkage practices in the US. Our findings can be used to promote further data linkages, facilitate sharing of data and linkage methodologies, and identify uses of the resulting linked data.

Framing niche-regime linkage as adaptation: An analysis of learning and innovation networks for sustainable agriculture across Europe

This paper draws on the transition literature to examine niche-regime interaction. Specifically it aims to reveal and contribute to an understanding of the processes that link sustainable agriculture innovation networks to the agricultural regime. It analyses findings from participatory workshops with actors in 17 Learning and Innovation Networks for Sustainable Agriculture (LINSA) across Europe. Framing linkage as an adaptive process, whereby regime actors and entities adapt to incorporate LINSA, and vice versa, reveals different patterns and processes of adaptation. Five adaptation modes are distinguished and described corresponding to different levels of adaptation between LINSA and the agricultural regime. Understanding adaptive linkage processes within and across these modes as reflexive, learning and networking processes enabled and facilitated by individuals and organisations provides more insights into linkage processes than a hierarchical approach. Analysis of results from 17 LINSA from a number of different contexts across Europe allows a broad empirical analysis and an overview of the interplay of processes contributing to the agricultural regime's adaptive capacity.

Smart Integrated Multiple Tracking System development for IOT based Target-oriented Logistics Location and Resource Service

With the rapid development of the IoT market many institutions are researching and developing various integrated IOT service platforms. Among them the development of IoT based tracking system requires a platform environment that can check in real time the target-oriented logistics movement status in industrial sites and social environments and manage resources. Previous related researches studied about particular single object tracking and about establishing a linkage process, but there were no studies about systems using Multiple Tracking System that target a variety of objects to establish a total task process such as for materials, personnel, and operations and process management. The study developed an efficient target-oriented smart integrated multiple tracking system that looks up object location based on real time and guarantees the accuracy and reliability of logistics location and resource management by combining the function of multiple tracking system.

REGRESSION ANALYSIS WITH LINKED DATA: PROBLEMS AND POSSIBLE SOLUTIONS.

In this paper we have described and extended some recent proposals on a general Bayesian methodology for performing record linkage and making inference using the resulting matched units. In particular, we have framed the record linkage process into a formal statistical model which comprises both the matching variables and the other variables included at the inferential stage. This way, the researcher is able to account for the matching process uncertainty in inferential procedures based on probabilistically linked data, and at the same time, he/she is also able to generate a feedback propagation of the information between the working statistical model and the record linkage stage. We have argued that this feedback effect is both essential to eliminate potential biases that otherwise would characterize the resulting linked data inference, and able to improve record linkage performances. The practical implementation of the procedure is based on the use of standard Bayesian computational techniques, such as Markov Chain Monte Carlo algorithms. Although the methodology is quite general, we have restricted our analysis to the popular and important case of multiple linear regression set-up for expository convenience.

Deterministic record linkage with indirect identifiers: data of the Berlin Myocardial Infarction Registry and the AOK Nordost for patients with myocardial infarction

How can 2 pseudonymised data sets be linked? Using the example of data from the Berlin Myocardial Infarction Registry and from a German sickness fund (AOK Nordost) we will demonstrate how record linkage can be achieved without personal identifiers. In different steps the method of deterministic record linkage with indirect identifiers: age, sex, hospital admission date and time, will be explained. We were able to show that 80.6% of the expected maximum number of patients were matched with our approach. As a result we had no duplicate matches in the linkage process, where one AOK patient was linked to 2 or more BMIR patients or vice versa. The matching variables produced enough uniqueness to be used as indirect patient identifiers. Deterministic record linkage with the following indirect indicators: age, sex, hospital admission date and time was possible in our study of patients with myocardial infarction in a circumscribed geographical region, which limited the number of cases and avoided mismatches.

Name segmentation using hidden Markov models and its application in record linkage.

This study aimed to evaluate the use of hidden Markov models (HMM) for the segmentation of person names and its influence on record linkage. A HMM was applied to the segmentation of patient's and mother's names in the databases of the Mortality Information System (SIM), Information Subsystem for High Complexity Procedures (APAC), and Hospital Information System (AIH). A sample of 200 patients from each database was segmented via HMM, and the results were compared to those from segmentation by the authors. The APAC-SIM and APAC-AIH databases were linked using three different segmentation strategies, one of which used HMM. Conformity of segmentation via HMM varied from 90.5% to 92.5%. The different segmentation strategies yielded similar results in the record linkage process. This study suggests that segmentation of Brazilian names via HMM is no more effective than traditional segmentation approaches in the linkage process.

Research on NC Machining and Accurate Modeling of Curve Bevel Gear

This paper first analyzes the NC simulation and NC machining process of curve bevel gear, and provides the basic equations and the formulae in detail based on the CNC 3 axis linkage machine tool cutting. Directly to takes the rotation angle of the work gear as machine tool motion parameters, the axes of other motion work piece express the gear angle function. Finally, according to the characteristics of curve bevel gear, we select reasonable processing technology, setting processing parameter of curve bevel gear, then test the tool path simulation and program processing, and finally the use of CNC milling machine with three linkage process curve bevel gear.

Population based surveillance in sickle cell disease: methods, findings and implications from the California registry and surveillance system in hemoglobinopathies project (RuSH).

There are no population-based surveillance systems to determine prevalence, impact or outcomes in sickle cell disease (SCD). Estimates of the SCD population in California range broadly from 4,500 to 7,000, and little is known about their health status, health care utilization or health outcomes. A surveillance strategy was implemented using diverse data sources to develop a multi-dimensional, state-based surveillance system for SCD that includes adults and children and describes utilization, treatment and outcomes. Data from California newborn screening, inpatient and emergency room records, Medi-Cal/Medicaid claims and two SCD special care centers were collected for 2004-2008. A multi-step, iterative linkage process was used to link and de-duplicate these data sources, and case definitions were used to categorize cases. After linking and de-duplicating, there were 1,975 confirmed cases of SCD, 3,159 probable cases as well as 8,024 possible cases. Among individual data sources, newborn screening and data from clinics contributed the greatest number of unique cases to the total. Select analyses of utilization and treatments for the population are described. Using linked existing data sources, an estimate of the statewide count of the SCD population is possible. The approach can be used to create an in-depth health status profile of the affected population by aggregating utilization, treatment, and outcomes data including mortality and morbidity information. This effort sets the stage for development of an on-going, state-based surveillance system.