Leren van toezicht

Toezicht staat onder immer toenemende belangstelling, of het nu gaat om het toezicht op financiële instellingen, de veiligheid van het vliegverkeer of de gezondheidszorg. De oorzaken hiervan zijn divers maar kunnen deels gevonden worden in het terugtreden van de overheid als uitvoerder van publieke diensten. Om controle te kunnen houden op die diensten zijn de afgelopen decennia grote toezichthoudende organen opgericht, die inmiddels een flink deel van de economie beslaan; volgens sommige berekeningen werken momenteel ongeveer een miljoen mensen in de ‘toezichtsindustrie’ (van Waarden 2006). Daarnaast dringt steeds meer het besef door dat we leven in een ‘risicomaatschappij’ (Beck 1992) die, hoe paradoxaal ook, aanleiding heeft gegeven tot een ‘veiligheidsutopie’ (Boutelier 2002). Risico’s worden steeds minder geaccepteerd en overheden en toezichthouders worden daar in toenemende mate op aangesproken. Deze trend brengt met zich mee dat onderzoek naar het functioneren van toezichthouders sterk in maatschappelijk belang heeft gewonnen. De afgelopen jaren is dan ook internationaal te constateren dat dit onderzoek een hoge vlucht heeft genomen. Ook de inspecties zelf hebben inmiddels onderzoeksprogramma’s opgezet. Dit geldt ook voor de Inspectie voor de Gezondheidszorg (IGZ). Het voorliggende rapport is een verslag van onderzoek naar de effectiviteit van een van de belangrijke toezichtsinstrumenten van de IGZ, het zogeheten Thematisch Toezicht. Middels casestudie onderzoek beoogt dit rapport de vraag te beantwoorden op welke manier het thematisch toezicht effectief kan zijn en voor welk type risicoproblemen deze vorm van toezicht het meest geschikt is. Hiermee probeert het rapport een zowel conceptuele als empirische bijdrage te leveren aan de discussie over het toezicht in algemene zin, en in het bijzonder over het toezicht op en in de gezondheidszorg

Improvement of Cardiac Function After Roux-en-Y Gastric Bypass in Morbidly Obese Patients Without Cardiac History Measured by Cardiac MRI

Purpose: Metabolic syndrome in patients with morbid obesity causes a higher cardiovascular morbidity, eventually leading to left ventricular hypertrophy and decreased left ventricular ejection fraction (LVEF). Roux-en-Y gastric bypass (RYGB) is considered the gold standard modality for treatment of morbid obesity and might even lead to improved cardiac function. Our objective is to investigate whether cardiac function in patients with morbid obesity improves after RYGB. Materials and Methods: In this single center pilot study, 15 patients with an uneventful cardiac history who underwent RYGB were included from May 2015 to March 2016. Cardiac function was measured by cardiac magnetic resonance imaging (CMRI), performed preoperatively and 3, 6, and 12 months postoperative. LVEF and myocardial mass and cardiac output were measured. Results: A total of 13 patients without decreased LVEF preoperative completed follow-up (mean age 37, 48.0 ± 8.8). There was a significant decrease of cardiac output 12 months postoperative (8.3 ± 1.8 preoperative vs. 6.8 ± 1.8 after 12 months, P = 0.001). Average myocardial mass declined by 15.2% (P < 0.001). After correction for body surface area (BSA), this appeared to be non-significant (P = 0.36). There was a significant improvement of LVEF/BSA at 6 and 12 months postoperative (26.2 ± 4.1 preoperative vs. 28.4 ± 3.4 and 29.2 ± 3.6 respectively, both P = 0.002). Additionally, there was a significant improvement of stroke volume/BSA 12 months after surgery (45.8 ± 8.0 vs. 51.9 ± 10.7, P = 0.033). Conclusion: RYGB in patients with morbid obesity with uneventful history of cardiac disease leads to improvement of cardiac function

Reducing the influence of geometry-induced gradient deformation in liquid chromatographic retention modelling

Rapid optimization of gradient liquid chromatographic (LC) separations often utilizes analyte retention modelling to predict retention times as function of eluent composition. However, due to the dwell volume and technical imperfections, the actual gradient may deviate from the set gradient in a fashion unique to the employed instrument. This makes accurate retention modelling for gradient LC challenging, in particular when very fast separations are pursued. Although gradient deformation has been addressed in method-transfer situations, it is rarely taken into account when reporting analyte retention parameters obtained from gradient LC data, hampering the comparison of data from various sources. In this study, a response-function-based algorithm was developed to determine analyte retention parameters corrected for geometry-induced deformations by specific LC instruments. Out of a number of mathematical distributions investigated as response-functions, the so-called “stable function” was found to describe the formed gradient most accurately. The four parameters describing the model resemble the statistical moments of the distribution and are related to chromatographic parameters, such as dwell volume and flow rate. The instrument-specific response function can then be used to predict the actual shape of any other gradient programmed on that instrument. To incorporate the predicted gradient in the retention modelling of the analytes, the model was extended to facilitate an unlimited number of linear gradient steps to solve the equations numerically. The significance and impact of distinct gradient deformation for fast gradients was demonstrated using three different LC instruments. As a proof of principle, the algorithm and retention parameters obtained on a specific instrument were used to predict the retention times on different instruments. The relative error in the predicted retention times went down from an average of 9.8% and 12.2% on the two other instruments when using only a dwell-volume correction to 2.1% and 6.5%, respectively, when using the proposed algorithm. The corrected retention parameters are less dependent on geometry-induced instrument effects

External quality assurance programme for enzymatic analysis of lysosomal storage diseases: A pilot study.

Item does not contain fulltextInborn errors of metabolism are rare and laboratories performing diagnostic tests in this field must participate in external quality assurance (EQA) schemes to demonstrate their competence and also to maintain sufficient experience with patient material. EQA schemes for metabolite analyses are available (ERNDIM), but corresponding EQA schemes for enzyme analyses are nonexistent. In this paper we describe a pilot study on lysosomal enzyme testing by four centres in The Netherlands. Quantitative aspects of EQA were studied by interlaboratory comparison of activities of six lysosomal enzymes in a series of buffy coat samples. Interlaboratory variance was enormous. To reduce variance caused by methodological differences, participants reported enzyme activities relative to mean normal values. beta-D: -Galactosidase activities compared well between the participating laboratories (average interlaboratory CV 13%), but for other enzymes large differences were observed, e.g. sphingomyelinase (average CV 38%). Diagnostic proficiency was tested with cultured fibroblasts. In 45 out of a total of 48 tests (12 cell lines, 4 participants) the correct diagnosis was accomplished on the basis of merely biochemical investigations, i.e. without clinical data of the patients. In a survey using blood of a late-onset Pompe disease patient, less conclusive results were obtained. A stable enzyme source was developed for easy distribution. Most lysosomal enzymes were stable upon lyophilization of leukocyte homogenates and during subsequent storage of the freeze-dried material at room temperature, in particular when cryolyoprotectant was added. Shipment of such lyophilized samples is simple and cheap and ideal for an EQA scheme. Our study shows that an EQA programme for enzymatic testing of lysosomal storage diseases is necessary to accomplish reliable diagnostic procedures for lysosomal storage diseases. We recommend that EQA for lysosomal enzymes be implemented through ERNDIM

Correction to: Age-Related Effects of Bariatric Surgery on Early Atherosclerosis and Cardiovascular Risk Reduction

Frederik H. W. Jonker and Vera A. A. van Houten contributed equally to this work

Chemometric Strategies for Fully Automated Interpretive Method Development in Liquid Chromatography

The majority of liquid chromatography (LC) methods are still developed in a conventional manner, that is, by analysts who rely on their knowledge and experience to make method development decisions. In this work, a novel, open-source algorithm was developed for automated and interpretive method development of LC(-mass spectrometry) separations ("AutoLC"). A closed-loop workflow was constructed that interacted directly with the LC system and ran unsupervised in an automated fashion. To achieve this, several challenges related to peak tracking, retention modeling, the automated design of candidate gradient profiles, and the simulation of chromatograms were investigated. The algorithm was tested using two newly designed method development strategies. The first utilized retention modeling, whereas the second used a Bayesian-optimization machine learning approach. In both cases, the algorithm could arrive within 4-10 iterations (i.e., sets of method parameters) at an optimum of the objective function, which included resolution and analysis time as measures of performance. Retention modeling was found to be more efficient while depending on peak tracking, whereas Bayesian optimization was more flexible but limited in scalability. We have deliberately designed the algorithm to be modular to facilitate compatibility with previous and future work (e.g., previously published data handling algorithms)