Alexander Lassnig

Simulation model for cost estimation of integrated care concepts of heart failure patients

BackgroundAs a direct result of the population growing older the total number of chronic illnesses increases. The future expenditure for care of chronically ill patients is an ever-present challenge for the health care system. New solutions based on integrated care or the inclusion of telemedical systems in the treatment procedure can be essential for reducing the future financial burden. Therefore a detailed economic model was developed, which enables the comparison of health and cost outcomes for conventional medical care and different integrated care concepts in heart failure treatment.MethodsFor modelling, the discrete event technique was used. The model takes outpatient care as well as inpatient care into account to estimate the total occurring costs. It enables the treatment of patients by a physician, a specialist or a clinical ambulance for the simulation of the outpatient care. For inpatient care the model considers the total-costs of the hospitalization and rate of re-admission and furthermore the costs which occur because of special medical treatments or necessary stay at intensive care units. To rate the severity of symptoms patients can be classified using NYHA groups. To outline some of the potential model results, two scenarios have been simulated to compare both methods of care regarding overall costs.ResultsThe developed simulation model allows comparing health and cost outcomes of different integrated care concepts for the treatment of heart failure patients. Additionally to the simulation of standard outpatient and inpatient care procedures in Austria the approach of a telemedical monitoring system for heart failure patients was implemented in this economic model. With the simulated scenarios it could be shown that under the given simulation parameters the telemedical system can lead to cost savings of up to 8% within the first three years.ConclusionsThe developed model represents a comprehensive tool, which opens a wide field of possible simulation scenarios for the treatment of heart failure patients with special focus on overall cost estimations and reimbursement strategies. The simulated scenarios show that telemedical care has the potential of improved health outcomes and economic benefits.

Temperature-induced modulation of voltage-gated ion channels in human lung cancer cell line A549 using automated patch clamp technology

In cancer cells specific ion channels exhibit altered channel expression, which can drive malignant and metastatic cell behavior. Hence, therapeutic strategies modulating ion channels prove to be promising in cancer therapeutics. Alterations in temperature, even small deviations from normothermia, may cause changes in electrophysiological processes, since activation and conductivity of various ion channels are temperature-dependent. In this pilot study, we focused on a basic understanding of the effects of temperature-alterations on voltage-gated ion channels of A549 cells using an automated patch-clamp system. The measurements were carried out in whole-cell voltage-clamped configuration applying test pulses between −60 and +60 mV. For positive voltages the ion-current curves showed an instantaneously increased conductance, followed by a slow current increase provoked by later activating voltage-gated ion channels, indicating the time-delayed response of additional channels. To investigate the temperature-dependent electrophysiological behavior, six cells (passages 7–10, n = 34) were examined at room temperature and normal body temperature. Compared to normal body temperature, reduced temperatures revealed a higher whole-cell current at negative voltages (63.4% (±18.5%), −60 mV) and lower currents (52.6% (±27.3%), +60 mV) at positive voltages, indicating a hypothermia-induced modulation of voltage-gated channels in the lung cancer cell line A549.

Estimating Cardiac Intensive Care Patients’ Responsiveness to Late Conservative Fluid Management Using Systems Analysis

Fluid overload is a common problem in critically ill patients who underwent surgery and is accompanied by a range of risks for severe organ damage. Therefore, in stable patients excess water should be removed using fluid-restricting treatment strategies in order to reach a neutral fluid balance as early as possible. Within this work, second order discrete-time transfer function models were identified for 10 selected cardiac patients staying at the intensive care unit for at least 5 days. For model estimation, the cumulative fluid intake and the cumulative fluid balance time series were used as model input and output parameters. Each individual model is capable of describing the respective patient’s cumulative fluid balance trajectory as response to the actually applied fluid therapy. In the context of decision support, systems analysis can therefore offer valuable tools not only for describing an individual patient’s reaction to a certain fluid therapy, but also for identifying patients with rebalancing issues at an early stage of recovery. In daily clinical practice, patient-specific transfer function models can be used for predicting the responsiveness to planned medical interventions, improving the fluid intake regime by focusing on the avoidance of a further increasing fluid overload and returning patients’ fluid balances to an acceptable level before release from the intensive care unit.

Usability evaluation of a locomotor therapy device considering different strategies

Abstract Usability of medical devices is one of the main determining factors in preventing use errors in treatment and strongly correlates to patient safety and quality of treatment. This thesis demonstrates the usability testing and evaluation of a prototype for locomotor therapy of infants. Therefore, based on the normative requirements of the EN 62366, a concept combined of evaluation procedures and assessing methods was created to enable extensive testing and analysis of the different aspects of usability. On the basis of gathered information weak points were identified and appropriate measures were presented to increase the usability and operating safety of the locomotor prototype. The overall outcome showed an usability value of 77.4% and an evaluation score of 6.99, which can be interpreted as “satisfactory”.

COMPARISON OF TELEMEDICAL AND CONVENTIONAL TREATMENT OF HEART FAILURE PATIENTS CONSIDERING DIFFERENT APPROACHES TO IN-HOSPITAL STAY

The double aging effect with its ensuing in- crease of chronic illnesses causes new challenges for public health care systems. New strategies and methods of care are essential to overcome the future financial bur- dens. The telemedical treatment of heart failure patients with the potential of improved medical and financial outcome has to be evaluated and analyzed. Therefore detailed discrete event models have been developed. For the first time clinical data for lengths of stay could be implemented as probability distribution functions in order to compare both systems. Results show that the median length of stay is not viable to compare the methods of treatment and that telemedical applications can be sus- tainable health care solutions with potential cost reduc- tions.