Data mining approach to estimate the duration of drug therapy from longitudinal electronic medical records

Background: Electronic Medical Records (EMRs) from primary/ ambulatory care systems present a new and promising source of information for conducting clinical and translational research. Objectives: To address the methodological and computational challenges in order to extract reliable medication information from raw data which is often complex, incomplete and erroneous. To assess whether the use of specific chaining fields of medication information may additionally improve the data quality. Methods: Guided by a range of challenges associated with missing and internally inconsistent data, we introduce two methods for the robust extraction of patient-level medication data. First method relies on chaining fields to estimate duration of treatment (“chaining”), while second disregards chaining fields and relies on the chronology of records (“continuous”). Centricity EMR database was used to estimate treatment duration with both methods for two widely prescribed drugs among type 2 diabetes patients: insulin and glucagon-like peptide-1 receptor agonists. Results: At individual patient level the “chaining” approach could identify the treatment alterations longitudinally and produced more robust estimates of treatment duration for individual drugs, while the “continuous” method was unable to capture that dynamics. At population level, both methods produced similar estimates of average treatment duration, however, notable differences were observed at individual-patient level. Conclusion: The proposed algorithms explicitly identify and handle longitudinal erroneous or missing entries and estimate treatment duration with specific drug(s) of interest, which makes them a valuable tool for future EMR based clinical and pharmaco-epidemiological studies. To improve accuracy of real-world based studies, implementing chaining fields of medication information is recommended.Publisher PDFPeer reviewe

Persistence to Treatment with Novel Antidiabetic Drugs (Dipeptidyl Peptidase-4 Inhibitors, Sodium-Glucose Co-Transporter-2 Inhibitors, and Glucagon-Like Peptide-1 Receptor Agonists) in People with Type 2 Diabetes

INTRODUCTION: Adequate persistence to antidiabetic treatment is highly important to achieve proper glycemic control. In this study we evaluate the persistence to treatment with dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter-2 inhibitors, and glucagon-like peptide-1 receptor agonists in a nationwide cohort of patients with type 2 diabetes. METHODS: Using a central database in Hungary, we analyzed the persistence to the treatment with dipeptidyl peptidase-4 inhibitors (n = 59,900), sodium-glucose co-transporter-2 inhibitors (n = 26,052), and glucagon-like peptide-1 receptor agonists (n = 17,332) at treatment intensification between 2014 and 2016. We also compared the persistence of dipeptidyl peptidase-4 inhibitors (n = 9163) and sodium-glucose co-transporter-2 inhibitors (n = 1257) in initial therapy to that of metformin (n = 79,305) or sulfonylureas (n = 29,057). The rates of persistence to treatment and risk of non-persistence are reported. RESULTS: The persistence rates of dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter-2 inhibitors, and glucagon-like peptide-1 receptor agonists at treatment intensification were 69.6%, 67.8%, and 66.3% at year 1 which decreased to 57.3%, 56.8%, and 52.1% by year 2, respectively. The risk of non-persistence was higher by 6.6% (95% CI 3.6-9.6) for sodium-glucose co-transporter-2 inhibitors and by 8.3% (95% CI 5.0-11.5) for glucagon-like peptide-1 receptor agonists as compared to dipeptidyl peptidase-4 inhibitors. Novel oral antidiabetic drugs in fixed versus free add-on combinations with metformin had higher persistence. The persistence to treatment with novel oral antidiabetic drugs in initial therapy was better (dipeptidyl peptidase-4 inhibitors, 59.6% and 47.6%; sodium-glucose co-transporter-2 inhibitors, 61.9% and 47.0%) than that of initial monotherapy with metformin (47.0% and 39.1%) or sulfonylureas (52.4% and 41.8%) at years 1 and 2, respectively. CONCLUSION: Analysis of persistence of treatment with novel glucose-lowering medications revealed differences between drug classes, favoring dipeptidyl peptidase-4 inhibitors vs. sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists. Persistence data of novel antihyperglycemic agents may be useful for guiding the decision at initiation of antidiabetic treatment. FUNDING: Hungarian Diabetes Association. Plain language summary available for this article

Performance evaluation of binary classifier using Relative Cost Curve

Maģistra darbs ir veltīts klasifikācijas algoritmu precizitātes novērtēšanas metodēm gadījumā, kad disklasifikācijas sekas atšķiras starp klasēm. Aprakstītas izmaksu līkņu un Brajera līkņu metodes. Galvenie rezultāti izstrādāti relatīvo izmaksu līkņu pieejai. Bināra klasifikatora precizitātes skalārai novertēšanai piedāvāts apskatīt laukumu virs līknes. Ir aprakstīts kā paplašināt metodi vairāku klašu problēmai, ar pieņēmumu, ka sagaidāmās izmaksas ir atkarīgas tikai no īstās klases disklasifikācijas. Atslēgas vārdi: klasifikācija, ROC līkne, izmaksu līkne, Brajera līkne, relatīvo izmaksu līkne.Master Thesis is devoted to methods of performance evaluation of classifier under unequal misclassification costs. Cost Curves and Brier Curves methods are described. Main results are developed for Relative Cost Curves technique. The concept of Area Above the Curve is introduced as scalar measure of classifier performance. Relative Cost Curves technique is extended to multicategory problems when misclassification costs depend only on the true class. Keywords: classification, ROC curve, Cost Curve, Brier Curve, Relative Costs Curve

An agregation approach for solving bilevel linear programming problems

Diplomdarbs ir veltīts divu līmeņu lineārās programmēšanas uzdevumam gadījumā, kad augšējā līmenī ir viena mērķa funkcija un apakšējā līmenī - vairākas. Par darba pamatu ir ņemts nestriktas matemātikas algoritms optimāla plāna noteikšanai, meklējot kompromisu starp augšējā un apakšējā līmeņa mērķa funkciju optimālām vērtībām. Uzdevuma risinājuma rezultāts ir atkarīgs no algoritmā izvēlētajiem parametriem. Diplomdarbā ir izstrādāta algoritma parametru analīzes metode, kura izmanto speciāli šim mērķim uzdotu faktoragregācijas operatoru. Darba praktiskā daļa satur optimālās izvietošanas problēmu, kuras risināšanas shēma ir ilustrēta ar skaitlisko piemēru. Atslēgas vārdi: Lineārā programmēšana, vairāku mērķa funkciju lineārās programmēšanas uzdevums, divu līmeņu lineārās programmēšanas uzdevums, agregācijas operators, visparinātais agregācijas operators.The thesis is devoted to bi-level linear programming problem with a single objective function on the upper level and multiple objective functions on the lower level. As initial point was taken fuzzy algorithm for finding optimal solutions by choosing compromises between upper and lower level functions' optimal values. The solution of the problem depends on the algorithm's parameters. Specially constructed quotient aggregation is applied in algorithm's parameters analysis method, which has been developed in the thesis. Practical part of the thesis contains optimal location problem, of which a solution scheme is illustrated by numerical example. Keywords: Linear programming, multi-objective linear programming problem, bilevel linear programming problem, aggregation operator, general aggregation operator

Evaluation of cardio-metabolic effects of treatment with incretin-based therapies in patients with type 2 diabetes

This dissertation provides a detailed exploration and valuable insights of type 2 diabetes management in the real-world setting. Incretin-based therapies and thiazolidinedione were found to provide higher chances of sustainable glycaemic and cardiovascular risk factor control, compared to older anti-diabetic treatment options. The project highlights alarming rates of the existing cardio-metabolic burden at the population level. Proper control in terms of timely intensification with anti-hyperglycaemic, anti-hypertensive, and anti-dyslipidemic therapies when needed, remains a key aspect to improve long-term outcomes in patients with type 2 diabetes

Kochen mit Tim Mälzer : ein Vergleich zwischen öffentlich - rechtlichem und privatem Sender

Diese Bachelorarbeit befasst sich mit der Fragestellung, inwieweit sich öffentlich-rechtliche und private Fernsehsendungen gleicher Thematik in Bezug auf Anspruch und Konzeption unterscheiden. Es soll zudem verdeutlicht werden, warum sich der jeweilige Sender für dieses Format entschieden hat. Am Beispiel von „Schmeckt nicht, gibt’s nicht!“ (VOX) und „Tim Mälzer kocht!“ (Das Erste) werden diese Punkte praktisch untersucht