Conrad Kobel

Diagnosis related groups in Europe : moving towards transparency, efficiency, and quality in hospitals?

Hospitals in most European countries are paid on the basis of diagnosis related groups. Reinhard Busse and colleagues find much variation within and between systems and argue that they could be improved if countries learnt from each other

How Well Do Diagnosis‐Related Groups Explain Variations In Costs Or Length Of Stay Among Patients And Across Hospitals? Methods For Analysing Routine Patient Data

We set out an analytical strategy to examine variations in resource use, whether cost or length of stay, of patients hospitalised with different conditions. The methods are designed to evaluate (i) how well diagnosis-related groups (DRGs) capture variation in resource use relative to other patient characteristics and (ii) what influence the hospital has on their resource use. In a first step, we examine the influence of variables that describe each individual patient, including the DRG to which the patients are assigned and a range of personal and treatment-related characteristics. In a second step, we explore the influence that hospitals have on the average cost or length of stay of their patients, purged of the influence of the variables accounted for in the first stage. We provide a rationale for the variables used in both stages of the analysis and detail how each is defined. The analytical strategy allows us (i) to identify those factors that explain variation in resource use across patients, (ii) to assess the explanatory power of DRGs relative to other patient and treatment characteristics and (iii) to assess relative hospital performance in managing resources and the characteristics of hospitals that explain this performance.

Comparison of Real-Time Elastography and Multiparametric MRI for Prostate Cancer Detection: A Whole-Mount Step-Section Analysis

OBJECTIVE The purpose of this study was to compare prostate cancer detection rate of real-time elastography (RTE) with that of multiparametric MRI to evaluate the advantages and disadvantages of the two methods. SUBJECTS AND METHODS Thirty-nine patients with biopsy-proven prostate cancer underwent both RTE and multiparametric MRI to localize prostate cancer before radical prostatectomy. RTE was performed to assess prostate tissue elasticity, and hard lesions were considered suspicious for prostate cancer. Multiparametric MRI included T2-weighted MRI, diffusion-weighted MRI (DWI), and contrast-enhanced MRI (CE-MRI) with an endorectal coil at 1.5 T. After radical prostatectomy, whole-mount step sections of the prostate were generated, and the prostate cancer detection rates with both modalities were analyzed for cancer lesions measuring 0.2 cm3 or larger. RESULTS Histopathologic examination revealed 61 cancer lesions. RTE depicted 39 of 50 cancer lesions (78.0%) in the peripheral zone and 2 of 11 (18.2%) in the transitional zone. Multiparametric MRI depicted 45 of 50 cancer lesions (90.0%) in the peripheral zone and 8 of 11 (72.7%) in the transitional zone. Significant differences between the two modalities were found for the transitional zone and anterior part in prostates with volumes greater than 40 cm3 (p<0.05). Detection rates for high-risk prostate cancer (Gleason score≥4 and 3) and cancer lesions with volumes greater than 0.5 cm3 were high for both methods (93.8% and 80.5% for RTE, 87.5% and 92.7% for multiparametric MRI). Volumetric measurements of prostate cancer were more reliable with T2-weighted MRI than with RTE (Spearman rank correlation, 0.72 and 0.46). CONCLUSION RTE and multiparametric MRI depicted high-risk prostate cancer with high sensitivity. However, multiparametric MRI seems to have advantages in tumor volume assessment and for the detection of prostate cancer in the transitional zone and anterior part within prostates larger than 40 cm3.

Different metabolic responses during incremental exercise assessed by localized 31P MRS in sprint and endurance athletes and untrained individuals.

Until recently, assessment of muscle metabolism was only possible by invasive sampling. 31P magnetic resonance spectroscopy (31P MRS) offers a way to study muscle metabolism non-invasively. The aim of the present study was to use spatially-resolved 31P MRS to assess the metabolism of the quadriceps muscle in sprint-trained, endurance-trained and untrained individuals during exercise and recovery. 5 sprint-trained (STA), 5 endurance-trained (ETA) and 7 untrained individuals (UTI) completed one unlocalized 31P MRS session to measure phosphocreatine (PCr) recovery, and a second session in which spatially-resolved 31P MR spectra were obtained. PCr recovery time constant (τ) was significantly longer in STA (50±17 s) and UTI (41±9 s) than in ETA (30±4 s), (P<0.05). PCr changes during exercise differed between the groups, but were uniform across the different components of the quadriceps within each group. pH during recovery was higher for the ETA than for the UTI (P<0.05) and also higher than for the STA (P<0.01). Muscle volume was greater in STA than in UTI (P<0.05) but not different from ETA. Dynamic 31P MRS revealed considerable differences among endurance and sprint athletes and untrained people. This non-invasive method offers a way to quantify differences between individual muscles and muscle components in athletes compared to untrained individuals.

WHY DO PATIENTS HAVING CORONARY ARTERY BYPASS GRAFTS HAVE DIFFERENT COSTS OR LENGTH OF STAY? AN ANALYSIS ACROSS 10 EUROPEAN COUNTRIES

We analyse variations in cost or length of stay (LoS) for 66,587 patients from 10 European countries receiving a coronary artery bypass graft (CABG) procedure. In five of these countries, variations in cost are analysed using log-linear models. In the other five countries, negative binomial regression models are used to explore variations in LoS. We compare how well each countrys diagnosis-related group (DRG) system and a set of patient-level characteristics explain these variations. The most important explanatory factors are the total number of diagnoses and procedures, although no clear effects are evident for our CABG-specific diagnostic and procedural variables. Wound infections significantly increase LoS and costs in most countries. There is no evidence that countries using larger numbers of DRGs to group CABG patients are better at explaining variations in cost or LoS. However, refinements to the construction of DRGs to group CABG patients might recognise first and subsequent CABGs or other specific surgical procedures, such as multiple valve repair.

Regression tree construction by bootstrap: Model search for DRG-systems applied to Austrian health-data

BackgroundDRG-systems are used to allocate resources fairly to hospitals based on their performance. Statistically, this allocation is based on simple rules that can be modeled with regression trees. However, the resulting models often have to be adjusted manually to be medically reasonable and ethical.MethodsDespite the possibility of manual, performance degenerating adaptations of the original model, alternative trees are systematically searched. The bootstrap-based method bumping is used to build diverse and accurate regression tree models for DRG-systems. A two-step model selection approach is proposed. First, a reasonable model complexity is chosen, based on statistical, medical and economical considerations. Second, a medically meaningful and accurate model is selected. An analysis of 8 data-sets from Austrian DRG-data is conducted and evaluated based on the possibility to produce diverse and accurate models for predefined tree complexities.ResultsThe best bootstrap-based trees offer increased predictive accuracy compared to the trees built by the CART algorithm. The analysis demonstrates that even for very small tree sizes, diverse models can be constructed being equally or even more accurate than the single model built by the standard CART algorithm.ConclusionsBumping is a powerful tool to construct diverse and accurate regression trees, to be used as candidate models for DRG-systems. Furthermore, Bumping and the proposed model selection approach are also applicable to other medical decision and prognosis tasks.

Coronary artery bypass grafts and diagnosis related groups: patient classification and hospital reimbursement in 10 European countries

BackgroundThe prospective reimbursement of hospitals through the grouping of patients into a finite number of categories (Diagnosis Related Groups, DRGs), is common to many European countries. However, the specific categories used vary greatly across countries, using different characteristics to define group boundaries and thus those characteristics which result in different payments for treatment. In order to assist in the construction and modification of national DRG systems, this study analyses the DRG systems of 10 European countries.AimsTo compare the characteristics used to categorise patients receiving a coronary artery bypass graft (CABG) surgery into DRGs. Further, to compare the structure into which DRGs are placed and the relative price paid for patients across Europe.MethodPatients with a procedure of CABG surgery are analysed from Austria, England, Estonia, Finland, France, Germany, Ireland, Poland, Spain and Sweden. Diagrammatic algorithms of DRG structures are presented for each country. The price in Euros of seven typical case vignettes, each made up of a set of a hypothetical patient’s characteristics, is also analysed for each country. In order to enable comparisons across countries the simplest case (index vignette) is taken as baseline and relative price levels are calculated for the other six vignettes, each representing patients with different combinations of procedures and comorbidities.ResultsEuropean DRG payment structures for CABG surgery vary in terms of the number of different DRGs used and the types of distinctions which define patient categorisation. Based on the payments given to hospitals in different countries, the most resource intensive patient, relative to the index vignette, ranges in magnitude from 1.37 in Poland to 2.82 in Ireland. There is also considerable variation in how much different systems pay for particular circumstances, such as the occurrence of catheterisation or presence of comorbidity.ConclusionPast experience of the construction of DRG systems for CABG patients demonstrates the variety of options available. It also highlights the importance of updating systems as frequently as possible, to incentivise best practice.