Diagnosis-related Groups Statistics Research Articles

Deprivation and stroke incidence, treatment and mortality in Germany

Abstract Background Previous research suggests that regional deprivation significantly influences the risk of stroke. However, little is known about regional differences in stroke incidence and mortality within Germany. Methods We utilized data from the Diagnosis Related Groups statistics (2016-2019) and the German Federal Register of Physicians (2019). We used negative binomial regression analysis to investigate the relationship between the German Index of Multiple Deprivation 2015, covering 401 districts and district-free cities in Germany, and stroke incidence, treatment, and mortality. Results The adjusted rate ratios of stroke incidence and mortality with the highest deprivation level compared with the least deprived area were 1.16 (95% CI [1.14, 1.17]) and 1.19 (95% CI [1.14, 1.23]), respectively. Furthermore, this study showed that the density of physicians was higher in district-free cities than in districts. Conclusions The findings document a relationship between regional deprivation and stroke incidence and mortality, and call for a more targeted approach to stroke prevention in deprived regions. Key messages • Regional deprivation in Germany linked to increased stroke incidence and mortality rates. • Policy action needed for effective prevention measures.

Impact of early death recording on international comparison of acute myocardial infarction mortality – administrative hospital data study using the example of Germany and the United States

BackgroundIn-hospital mortality from acute myocardial infarction (AMI) is widely used in international comparisons as an indicator of health system performance. Because of the high risk of early death after AMI, international comparisons may be biased by differences in the recording of early death cases in hospital inpatient data. This study examined whether differences in the recording of early deaths affect international comparisons of AMI in-hospital mortality by using the example of Germany and the United States, and explored approaches to address this issue.MethodsThe German Diagnosis-Related Groups Statistics (DRG Statistics), the U.S. National Inpatient Sample (NIS) and the U.S. Nationwide Emergency Department Sample (NEDS) were analysed from 2014 to 2019. Cases with treatment for AMI were identified in German and U.S. inpatient data. AMI deaths occurring in the emergency department (ED) without inpatient admission were extracted from NEDS data. 30-day in-hospital mortality figures were calculated according to the OECD indicator definition (unlinked data) and modified by including ED deaths, or excluding all same-day cases.ResultsGerman age-and-sex standardized 30-day in-hospital mortality was substantially higher compared to the U.S. (in 2019, 7.3% vs. 4.6%). The ratio of German vs. U.S. mortality was 1.6. After inclusion of ED deaths in U.S. data this ratio declined to 1.4. Exclusion of same-day cases in German and U.S. data led to a similar ratio.ConclusionsWhile short-duration treatments due to early death are generally recorded in German inpatient data, in U.S. inpatient data those cases are partially missing. Excluding cases with short-duration treatment from the calculation of mortality indicators could be a feasible approach to account for differences in the recording of early deaths, that might be existent in other countries as well.

Hospital Incidence and Treatment Outcomes of Patients with Aneurysms and Dissections of the Iliac Artery in Switzerland-A Secondary Analysis of Swiss DRG Statistics Data.

Background/Objectives: Aneurysms and dissections of the iliac artery (ADIAs) are significant vascular conditions often associated with aortic pathologies. Despite their importance, reports on isolated iliac artery pathologies are rare. This study aimed to investigate the epidemiology of ADIA in Switzerland including treatment incidence and hospital outcomes. Methods: A retrospective analysis of diagnosis-related group (DRG) statistics from 2011 to 2018 in Switzerland was conducted, identifying all cases of ADIA while excluding those with concomitant treatment of aortic pathologies. Age-standardized incidence rates and treatment outcomes were assessed, with multivariable logistic regression performed to identify factors associated with hospital mortality. Results: From 2011 to 2018, 1037 ADIA cases were hospitalized in Switzerland. Incidence rates for elective treatment were significantly higher in men than women, increasing in men from 1.5 to 2.4 cases per 100,000 men (p = 0.007), while remaining stable in women at around 0.2 cases per 100,000 women. Acute treatment incidence rates were lower but still higher in men, at 0.9 cases per 100,000 men and 0.2 cases per 100,000 women. Crude hospital mortality rates were lower for endovascular repair than open surgical repair in both elective (0.8% vs. 3.1%, p = 0.023) and emergency treatment (6.7% vs. 18.4%, p = 0.045). Multivariable analysis showed that endovascular repair was associated with significantly reduced hospital mortality compared to open repair (OR 0.27, 95%-CI: 0.10 to 0.66, p = 0.006). Conclusions: This nationwide study of iliac artery pathologies shows that the treatment incidence was about 10 times higher in men than in women for elective procedures, but only about five times higher for emergency treatment. Endovascular procedures were associated with significantly lower hospital mortality than open procedures, while hospital mortality rates were comparable for men and women.

Diabetes-related amputations in Germany: analysis of time trend from 2015 to 2022 and differences by area-level socioeconomic deprivation.

Diabetes-related amputations reduce health-related quality of life and are an indicator of the quality of care of diabetes. Population-based age-standardized rates for diabetes-related cases of major and minor amputation were calculated and reported for the years 2015 - 2022 using the Diagnosis-related groups statistics. For 2022 these rates were also reported according to area-level socioeconomic deprivation. Diabetes-related major amputations decreased from 6.8 to 5.2 per 100,000 residents in women and from 18.6 to 17.5 per 100,000 residents in men between 2015 and 2022. In 2021 and 2022, there was no further decrease in men compared to the previous year. Diabetes-related minor amputations decreased in women between 2015 and 2022, but increased in men. Amputation rates were higher in regions with high deprivation than in regions with low deprivation. Diabetes care should consider socioeconomic differences into account. The monitoring of the trends in amputations needs to be continued.

Editor's Choice – Temporal fluctuations of hospital incidence and mortality of ruptured abdominal aortic aneurysms in Germany: A secondary data analysis of German hospital episode statistics 2009 – 2018

Rupture of abdominal aortic aneurysms (rAAA) is still associated with high mortality. Recent studies have shown higher incidences in autumn and winter, and worse outcomes after rAAA treatment on weekends in some countries. This study aimed to analyse for seasonal, weekday, and daytime fluctuations of the hospital incidence, treatment modalities, and outcomes of rAAA, based on most recent nationwide German real world data. A secondary data analysis of diagnosis related group statistics (2009 - 2018), obtained from the German Federal Statistical Office, was conducted. Cases encoded by a diagnosis of rAAA in conjunction with procedural codes for endovascular aortic repair (EVAR) or open aortic repair were included. Patient and procedural characteristics, comorbidities, and outcomes were analysed for seasonal (spring, summer, autumn, and winter), weekday (Monday - Sunday) and daytime (0:00 - 8:00, 8:00 -16:00, 16:00 -20:00, and 20:00 - 24:00) fluctuations by descriptive statistics and multivariable regression analyses. Thirteen thousand and seventy patients (85% male, median age 75 years) were treated for rAAA. Endovascular aortic repair was associated with lower mortality (adjusted OR 0.40, 95% CI 0.37 - 0.44). While no significant seasonal fluctuations were found, on a weekday basis lower hospital incidences were found on Mondays (12%) and Sundays (11%) compared with other weekdays (15 - 16%). Similarly, EVAR rates were lower on Mondays and Sundays (25% and 24%, respectively) compared with other weekdays (30 - 33%). Furthermore, multivariable analyses revealed higher mortalities on Mondays and Sundays. On a daytime basis, lower EVAR rates and higher mortalities were found during the 16:00 - 8:00 period. In German hospitals, incidences and EVAR rates to treat rAAA were lowest on Mondays and Sundays. The associated overall mortalities were highest on the respective days. Further structuration and centralisation of AAA treatment in Germany could potentially mitigate this weekday effect.

The impact of regional deprivation on stroke incidence, treatment, and mortality in Germany

BackgroundRegional deprivation has been shown to be an influential factor in stroke incidence risk. However, there is a paucity of knowledge on regional differences in stroke incidence and mortality in Germany.MethodsWe assessed data from the Diagnosis Related Groups statistics (2016–2019) and the German Federal Registry of Physicians (2019). Negative binomial regression analysis was used to examine the association between the German Index of Multiple Deprivation 2015 covering 401 districts and district-free cities in Germany and stroke incidence, treatment, and mortality.ResultsThe adjusted rate ratios of stroke incidence and mortality with the highest deprivation level compared with the least deprived area were 1.161 (95% CI [1.143, 1.179]) and 1.193 (95% CI [1.148, 1.239]), respectively. Moreover, this study revealed that physician density was higher in district-free cities compared to districts.ConclusionsOur results indicate that regional deprivation is associated with incident and mortality cases of stroke, necessitating a more targeted approach to stroke prevention in deprived regions.

Utilization and Regional Differences of In-Patient Services for Peripheral Arterial Disease and Acute Limb Ischemia in Germany: Secondary Analysis of Nationwide DRG Data.

Background: Peripheral arterial disease (PAD) and acute limb ischemia (ALI) pose an increasing strain on health care systems. The objective of this study was to describe the German health care landscape and to assess hospital utilization with respect to PAD and ALI. Methods: Secondary data analysis of diagnosis-related group statistics data (2009–2018) provided by the German Federal Statistical Office. Inclusion of cases encoded by the International Classification of Diseases (ICD-10) codes for PAD and arterial embolism or thrombosis. Construction of line diagrams and choropleth maps to assess temporal trends and regional distributions. Results: A total of 2,589,511 cases (median age 72 years, 63% male) were included, of which 2,110,925 underwent surgical or interventional therapy. Overall amputation rate was 17%, with the highest rates of minor (28%) and major amputations (15%) in patients with tissue loss. In-hospital mortality (overall 4.1%) increased in accordance to Fontaine stages and was the highest in patients suffering arterial embolism or thrombosis (10%). Between 2009 and 2018, the annual number of PAD cases with tissue loss (Fontaine stage IV) increased from 97,092 to 111,268, whereby associated hospital utilization decreased from 2.2 million to 2.0 million hospital days. Hospital incidence and hospital utilization showed a clustering with the highest numbers in eastern Germany, while major amputation rate and mortality were highest in northern parts of Germany. Conclusions: Increased use of endovascular techniques was observed, while hospital utilization to treat PAD with tissue loss has decreased. This is despite an increased hospital incidence. Addressing socioeconomic inequalities and a more homogeneous distribution of dedicated vascular units might be advantageous in reducing the burden of disease associated with PAD and ALI.

Recording Trauma Care in German Hospital Discharge Data: Services Provided by Hospitals Owned by Workers' Compensation Funds and Financed through Statutory Accidental Insurance

In Germany, the Diagnosis-Related Group Statistics (DRG Statistics) represent an almost complete discharge data-based registry of inpatient services in acute care hospitals. However, services of hospitals owned by workers' compensation funds and financed through the statutory insurance for occupational accidents are excluded from the obligation of submitting hospital discharge data. Hence, the DRG statistics might be incomplete regarding inpatient services for trauma care. In order to illustrate trauma and post-trauma care in acute care hospitals, groups of specific inpatient services were defined. Numbers of cases according to these groups were identified in the microdata of the DRG statistics, as well as in the inpatient data of all nine workers' compensation funds hospitals in Germany. By dividing cases financed through the statutory insurance for occupational accidents from cases financed through other payers, the overlap of both databases as well as the share of cases not recorded in the DRG statistics were quantified. The analysis comprised data of 2016-2018. Depending on the type of service, the share of cases not recorded in the DRG statistics varied between 0.1% and more than 60% (accumulated 2016 to 2018). There was under-recording of early-stage rehabilitation for traumatic brain injury (61%), treatment for traumatic paraplegia (14% for initial treatment and 23% for subsequent treatment), treatment for amputation injury (13%) and treatment for severe hand injury (5%). Regarding inpatient services that are not covered by the statutory insurance for occupational accidents, the microdata of the DRG statistics can be considered as virtually complete. However, inpatient services for trauma care are not completely recorded because discharge data are not submitted by hospitals run by workers' compensation funds when services are financed through the statutory insurance for occupational accidents. Analyses of trauma care can only be complete if data of hospitals financed by workers' compensation funds are included.

Trends in radiotherapy inpatient admissions in Germany: a\xa0population-based study over a\xa010-year period

ObjectiveWith the increasing complexity of oncological therapy, the number of inpatient admissions to radiotherapy and non-radiotherapy departments might have changed. In this study, we aim to quantify the number of inpatient cases and the number of radiotherapy fractions delivered under inpatient conditions in radiotherapy and non-radiotherapy departments.MethodsThe analysis is founded on data of all hospitalized cases in Germany based on Diagnosis-Related Group Statistics (G-DRG Statistics, delivered by the Research Data Centers of the Federal Statistical Office). The dataset includes information on the main diagnosis of cases (rather than patients) and the performed procedures during hospitalization based on claims of reimbursement. We used linear regression models to analyze temporal trends. The considered data encompass the period from 2008 to 2017.ResultsOverall, the number of patients treated with radiotherapy as inpatients remained constant between 2008 (N = 90,952) and 2017 (N = 88,998). Starting in January 2008, 48.9% of 4000 monthly cases received their treatment solely in a radiation oncology department. This figure decreased to 43.7% of 2971 monthly cases in October 2017. We found a stepwise decrease between December 2011 and January 2012 amounting to 4.3%. Fractions received in radiotherapy departments decreased slightly by 29.3 (95% CI: 14.0–44.5) fractions per month. The number of days hospitalized in radiotherapy departments decreased by 83.4 (95% CI: 59.7, 107.0) days per month, starting from a total of 64,842 days in January 2008 to 41,254 days in 2017. Days per case decreased from 16.2 in January 2008 to 13.9 days in October 2017.ConclusionOur data give evidence to the notion that radiotherapy remains a discipline with an important inpatient component. Respecting reimbursement measures and despite older patients with more comorbidities, radiotherapy institutions could sustain a constant number of cases with limited temporal shifts.

Factitious disorders in Germany\u2013a detailed insight

Factitious disorders (FDs) are well known to a majority of physicians; however, the corresponding ICD-10 diagnosis F68.1 remains severely under assigned and often misdiagnosed. Based on a previously conducted nationwide survey in Germany, we extended the analyzed variables to further understand FD characteristics.The assignments regarding the following variables in the German diagnosis-related group statistics were analyzed: residence of the patient and location of the diagnosing institution, primary referral to the diagnosing institution, reason for admission and discharge, specialty department, total length of stay, length of stay in the longest treating department, surgery performed, case mix revenue, regional type of the treating institution, and patients’ region of origin.A very distinct difference was observed in the assignment rates based on the homeland of the diagnosed patient and diagnosing institution. The assignment rate showed no significant difference across German regions. Based on our findings, a patient with FD in Germany might exhibit the following “typical” traits: A woman in her late thirties from a rural area is referred by a physician or another hospital wherein she was previously treated for more than a day to an institution for fully inpatient hospital treatment wherein she completes her treatment regularly. Dermatology, neurology, emergency, and internal medicine departments tend to be confronted with patients with FDs more often than other departments; however, surgery is performed in every fifth case. Patients are primarily treated in only one department for ~ 25 days. The case mix revenue will most probably not exceed €5000.

Editor's Choice – Distribution of Care and Hospital Incidence of Carotid Endarterectomy and Carotid Artery Stenting: A Secondary Analysis of German Hospital Episode Data

This is a description of the German healthcare landscape regarding carotid artery disease, assessment of hospital incidence time courses for carotid endarterectomy (CEA) and carotid artery stenting (CAS), and simulation of potential effects of minimum hospital caseload requirements for CEA and CAS. The study is a secondary data analysis of diagnosis related group statistics data (2005-2016), provided by the German Federal Statistical Office. Cases encoded by German operation procedure codes for CEA or CAS and by International Classification of Diseases (ICD-10) codes for carotid artery disease were included. Hospitals were categorised into quartiles according to annual caseloads. Linear distances to the closest hospital fulfilling hypothetical caseload requirements were calculated. A total of 132 411 and 33 709 patients treated with CEA and CAS from 2012 to 2016 were included. CEA patients had lower rates of myocardial infarction (1.4% vs. 1.8%) and death (1.2% vs. 4.0%), and CAS patients were more often treated after emergency admission (38.1% vs. 27.1%). Age standardised annual hospital incidences were 67.2 per 100 000 inhabitants for CEA and 16.3 per 100 000 inhabitants for CAS. The incidence for CEA declined from 2005 to 2016, with CAS rising again until 2016 after having declined from 2010 to 2013. Regarding distance from home to hospital, centres offering CEA are distributed more homogeneously across Germany, compared with those performing CAS. Hypothetical introduction of minimum annual caseloads (> 20 for CEA; > 10 for CAS) imply that 75% of the population would reach their hospital after travelling 45 km for CEA and 70 km for CAS. Differences in spatial distribution mean that statutory minimum annual caseloads would have a greater impact on CAS accessibility than CEA in Germany. Presumably because of a decline in carotid artery disease and a transition towards individualised therapy for asymptomatic patients, hospital incidence for CEA has been declining.

Crohn\u2019s disease: a population-based study of surgery in the age of biological therapy

PurposeDespite primary conservative therapy for Crohn’s disease, a considerable proportion of patients ultimately needs to undergo surgery. Presumably, due to the increased use of biologics, the number of surgeries might have decreased. This study aimed to delineate current case numbers and trends in surgery in the era of biological therapy for Crohn’s disease.MethodsNationwide standardized hospital discharge data (diagnosis-related groups statistics) from 2010 to 2017 were used. All patients who were admitted as inpatient Crohn’s disease cases in Germany were included. Time-related development of admission numbers, rate of surgery, morbidity, and mortality of inpatient Crohn’s disease cases were analyzed.ResultsA total number of 201,165 Crohn’s disease cases were included. Within the analyzed time period, the total number of hospital admissions increased by 10.6% (n = 23,301 vs. 26,069). While gender and age distribution remained comparable, patients with comorbidities such as stenosis formation (2010: 10.1%, 2017: 13.4%) or malnutrition (2010: 0.8%, 2017: 3.2%) were increasingly admitted. The total number of all analyzed operations for Crohn’s disease increased by 7.5% (2010: n = 1567; 2017: n = 1694). On average, 6.8 ± 0.2% of all inpatient patients received ileocolonic resections. Procedures have increasingly been performed minimally invasive (2010: n = 353; 2017: n = 687). The number of postoperative complications remained low.ConclusionDespite the development of novel immunotherapeutics, the number of patients requiring surgery for Crohn’s disease remains stable. Interestingly, patients have been increasingly hospitalized with stenosis and malnutrition. The trend towards more minimally invasive operations has not relevantly changed the rate of overall complications.

Acute Appendicitis: Trends in Surgical Treatment—A Population-Based Study of Over 800 000 Patients.

Appendectomy is the gold standard for treatment of acute appendicitis. However, recent studies favor primary antibiotic therapy. The aim of this observational study was to explore changes in the numbers of operations for acute appendicitis in the period 2010-2017, paying special attention to disease severity. Data from diagnosis-related group statistics were used to analyze the trends, mortality, and complication rates in the surgical treatment of appendicitis in Germany between 2010 and 2017. All cases of appendectomy after a diagnosis of appendicitis were included. Altogether, 865 688 inpatient cases were analyzed. The number of appendectomies went down by 9,8%, from 113 614 in 2010 to 102 464 in 2017, while the incidence fell from 139/100 000 in 2010 to 123/100 000 in 2017 (standardized by age group). This decrease is due to the lower number of operations for uncomplicated appendicitis (79 906 in 2017 versus 93 135 in 2010). Hospital mortality decreased both in patients who underwent surgical treatment of complicated appendicitis (0.62% in 2010 versus 0.42% in 2017) and in those with a complicated clinical course (5.4% in 2010 versus 3.4% in 2017). Decisions on the treatment of acute appendicitis in German hospitals follow the current trend towards non-surgical management in selected patients. At the same time, the care of acute appendicitis has improved with regard to overall hospital morbidity and hospital mortality.

Epidemiology of Sepsis Among Children and Neonates in Germany: Results From an Observational Study Based on Nationwide Diagnosis-Related Groups Data Between 2010 and 2016.

Worldwide, more than half of all sepsis cases occur in pediatric and adolescent patients, particularly in neonates. Previous population-based studies in these age groups often were limited to either neonatal or pediatric patients admitted to ICUs. We aimed to investigate the overall and age-specific incidence and case fatality of sepsis in children in Germany, a high-income country with a total population of 82 million. Retrospective observational study based on the German Diagnosis-related Groups statistics of the years 2010-2016. All acute care hospitals in Germany except for prison and psychiatric hospitals. Pediatric patients less than or equal to 19 years with International Classification of Diseases, 10th Revision-coded sepsis, neonates with International Classification of Diseases, 10th Revision-coded neonatal sepsis. None. We analyzed pediatric sepsis incidence in patients aged birth to less than or equal to 19 years old, case fatality, and underlying comorbidities, and neonatal sepsis incidence and case fatality within the neonatal period. We identified 14,635 pediatric sepsis cases among 15.4 million pediatric hospitalizations between 2010 and 2016 (= 0.1% of pediatric hospitalizations). The incidence of pediatric sepsis was 14 cases per 100,000 children between 0 and 19 years. Case fatality was 16.6% and decreased from 17.8% (2010) to 15.0% (2016). A total of 11.5% of hospital deaths in the age group 0-19 years were associated with pediatric sepsis. Sepsis incidence and case fatality were highest in children less than 1 year old and declined in older children and adolescents. Admissions with pediatric sepsis were more common in children with preexisting comorbidities compared with those without (0.52% vs 0.03% of pediatric admissions). In neonates, the incidence of neonatal sepsis was 1,006 cases per 100,000 live births. Case fatality was 3.9%. While 17.7% of very low birth weight infants had neonatal sepsis, only 2.1% of low birth weight and 0.6% of normal birth weight neonates were affected, respectively. Sepsis is also in Germany a common and frequently fatal condition in pediatric patients, particularly among neonates and children with comorbidities.

The Effects of Minimum Caseload Requirements on Management and Outcome in Abdominal Aortic Aneurysm Repair.

The German quality assurance guideline on abdominal aortic aneurysm (AAA) was implemented by the Joint Federal Committee (Gemeinsamer Bundesausschuss, G-BA) in 2008. The aims of this study were to verify the association between hospital case volume and outcome and to assess the hypothetical effect of minimum caseload requirements. The German diagnosis-related groups statistics for the years 2012 to 2016 were scrutinized for AAA (ICD-10 GM I71.3/4) with procedure codes for endo - vascular or open surgical treatment. The primary endpoint was in-hospital mortality. Logistic regression models were used for risk adjustment, and odds ratios (OR) were calculated as a function of the annual hospital-level case volume of AAA. In a hypo - thetical approach, the linear distances for various minimum caseloads (MC) were evaluated to assess accessibility. The mortality of intact AAA (iAAA) was 2.7% (men [M] 2.4%, women [W] 4.2%); ruptured AAA (rAAA), 36.9% (M 36.9%, F 37.5%). An inverse relationship between annual hospital case volume of AAA and mortality was confirmed (iAAA/rAAA: from 3.9%/51% [<10 cases/year] through 3.3%/37% [30-39 cases/year] to 1.9%/28% [≥ 75 cases/year]). For a reference category of 30 AAA procedures/year, the following significant OR were found: 10 AAA cases/year, OR 1.21 (95% confidence interval [1.20; 1.21]); 20 cases, OR 1.09 [1.09; 1.09]; 50 cases, OR 0.89 [0.89; 0.89]; 75 cases, OR 0.82 [0.82; 0.82]. In a hypothetical centralization scenario with assumed MC of 30/year, 86% of the population would have to travel less than 100 km to the nearest hospital; with an MC of 40, this would apply to only 50% (without redistribution effects). In the observed period, a significant correlation was confirmed between high annual case volume and low in-hospital mortality. A minimum caseload requirement of 30 AAA operations/year seems reasonable in view of the accessibility of hospitals. Cite this.

Outcome Quality Beyond the Mean - An Analysis of 43,231 Pancreatic Surgical Procedures Related to Hospital Volume.

The aim of this study was to examine whether elevated in-hospital mortality rates in lower volume hospitals are only valid on average or also apply for individual hospitals. Various studies demonstrated a volume-outcome relationship in pancreatic surgery with increased mortality in low volume hospitals. However, almost all studies assessed quality indicators only for groups of hospitals by averaged measures, neglecting variability of hospital performance. The German nationwide hospital discharge data (diagnosis-related groups-statistics) was used to determine risk-adjusted in-hospital mortality for all distal pancreatectomies (DP), pancreatoduodenectomies (Whipple-proce-dure, PD), and pylorus-preserving pancreatoduodenectomies (PPD) performed between 2011 and 2015. Hospitals were stratified according to annual and 5-year total procedure volume and examined in relation to average in-hospital mortality of the highest volume quintile. Lowest adjusted mortality rates were observed in highest volume quintiles for each pancreatic resection procedure, with 6.2% for DP, 8.3% for PD, and 5.7% for PPD in the 5-year observation period. With these mortality rates as reference values the analysis revealed that a non-negligible proportion of hospitals performed equal or better (DP: 430/784, 54.5%; PD: 269/611, 44.0%; PPD: 255/565, 45.1%) than the hospitals of the highest volume quintile. High quality of care, with in-hospital mortality rates less or equal to high-volume hospitals, is also achieved in hospitals with lesser procedure volume. Therefore, mere volume seems not suitable as proximal measure for assessing individual hospital quality. instead, more sophisticated certification systems, that allow accurate quality assessment and better reflect clinical variability, should preferred to fixed minimum volume thresholds.

Comparability of different data sources on stroke care in Germany

This article reviews different methodological approaches for determining treatment reality of ischemic stroke patients in acute care hospitals. Considering specific advantages and disadvantages of two different epidemiologic approaches, aspecific comparison was carried out of cases from a structured analysis of the nationwide German diagnosis-related groups (DRG) statistics and data from the acute stroke treatment in Hesse (SA_HE) for 2018 collated by the office for quality management. According to the DRG statistics and the SA_HE data, 16,267 and 15,643 acute ischemic stroke patients (ICD code I63) were treated in Hesse in 2018, with 53.7% and 54.5% males, respectively. The overall age distribution did not show significant differences between the two data sources; however, stroke patients over the age of 70years were registered significantly more often in the DRG statistics. The rates of systemic thrombolysis were 16.5% in both data sources and the rates of mechanical thrombectomy were 5.6% and 5.9%, respectively. The analysis shows that after a rational limitation of the included cases and based on the place of treatment, there were no statistically significant differences concerning the number of hospitalized patients with ischemic stroke, distribution of gender and age as well as the documented rates of systemic thrombolysis and mechanical thrombectomy. It can therefore be concluded that the well-controlled stroke quality register examined is able to capture asufficient number of hospitalized acute ischemic stroke cases and treatment rates. Therefore, it appears to be recommendable to adopt the strict Hessian guidelines for data acquisition and control nationwide. In this way anationwide combined analysis of data from the working group of German stroke registers and the DRG statistics would be possible.

Ranking of the most relevant hospital inpatient diagnoses by age and diagnostic group based on DRG statistics in Germany

Inpatient healthcare demand is influenced by demographic changes; however, existing research mainly focuses on age-related conditions among older age groups and lacks empirical evidence. We aimed to identify important indicator diagnoses by group, which best characterise age-specific conditions and their demand of inpatient services in Germany. Data stem from the general hospital diagnosis-related group (DRG) statistics in Germany from 2005 to 2010. To identify the indicator diagnosis groups, we used frequency analyses of individual diagnoses and combined them into common diagnosis groups, stratified by age and gender. We identified indicator diagnoses by the highest number of cases of inpatient hospital treatments in 2010 or the largest change in cases between 2005 and 2010. The most common diagnosis groups were then ranked using different weights. Changes were quantified using linear regression. Across all ages, 13 diagnosis groups were identified as frequently reported hospitalisations such as injuries to the head (S00-S09) among patients aged 0 to 17 years, and ischemic heart diseases (I20-I25) among patients aged 18 to 64 years. As the number of hospitals decreased, the demand in inpatient services increased. From 75 years and above, males were more frequently inpatients than females, and overall length of stay in hospitals appeared to decrease. We empirically identified 13 diagnosis groups, which best describe the inpatient services utilised among various age groups in a ranked order. Findings from this study can provide a platform for determining future demand of inpatient services as well as the demographic-specific diagnoses that need attention.

Definition of Variables in Hospital Discharge Data: Pitfalls and Proposed Solutions

In Germany, the Diagnosis-Related Group Statistics (DRG Statistics) supply full coverage of inpatient episodes in acute care hospitals. The Research Data Centres of the Federal Statistical Office and the Statistical Offices of the Federal States provide the microdata of the DRG Statistics, namely hospital discharge files of each inpatient case, for scientific research. Hospital discharge data are generated for administrative purposes. As well as other data sources, they have specific features and characteristics, which should be considered in planning and designing research studies. A key challenge is the appropriate and sophisticated operationalization of units of analysis, targets variables, and other study variables. The methodological approach should consider, among other factors, differing coding behaviour between hospitals in order to minimize the risk of bias. This contribution shows by practical examples what should be incorporated in variable definition to ensure that the risk of bias by coding behaviour or other factors is minimized to the greatest possible degree. First of all, the features and characteristics of the German hospital discharge data are outlined. Based on the authors' experiences, basic steps and challenges in observational health services research studies are described. Examples are illustrated by our own calculations, derived from previous studies based on the microdata of the DRG Statistics. The reliability and validity of analyses based on hospital discharge data are crucially dependent on the appropriateness of variable definition. To minimize the risk of bias and misinterpretation, extensive preliminary considerations are required which involve clinical aspects, as well as the context of data collection and technical classification opportunities. Hopefully, there will be greater acceptance of research based on hospital discharge data, so that these valuable data will be used more frequently for research purposes in the future.

Adjusting selection bias in German health insurance records for regional prevalence estimation

BackgroundRegional prevalence estimation requires epidemiologic data with substantial local detail. National health surveys may lack in sufficient local observations due to limited resources. Therefore, corresponding prevalence estimates may not capture regional morbidity patterns with the necessary accuracy. Health insurance records represent alternative data sources for this purpose. Fund-specific member populations have more local observations than surveys, which benefits regional prevalence estimation. However, due to national insurance market regulations, insurance membership can be informative for morbidity. Regional fund-specific prevalence proportions are selective in the sense that the morbidity structure of a fund’s member population cannot be extrapolated to the national population. This implies a selection bias that marks a major obstacle for statistical inference. We provide a methodology to adjust fund-specific selectivity and perform regional prevalence estimation from health insurance records. The methodology is applied to estimate regional cohort-referenced diabetes mellitus type 2 prevalence in Germany.MethodsRecords of the German Public Health Insurance Company from 2014 and Diagnosis-Related Group Statistics data are combined within a benchmarked multi-level model. The fund-specific selectivity is adjusted in a two-step procedure. Firstly, the conditional expectation of the insurance company’s regional prevalence given related inpatient diagnosis frequencies of its members is quantified. Secondly, the regional prevalence is estimated by extrapolating the conditional expectation using corresponding inpatient diagnosis frequencies of the Diagnosis-Related Group Statistics as benchmarks. Model assumptions are validated via Monte Carlo simulation. Variable selection is performed via multivariate methods. The optimal model fit is determined by analysis of variance. 95% confidence intervals for the estimates are constructed via semiparametric bootstrapping.ResultsThe national diabetes mellitus type 2 prevalence is estimated at 8.70% with a 95% confidence interval of [8.48%, 9.35%]. This indicates an adjustment of the original fund-specific prevalence from − 32.79 to − 25.93%. The estimated disease distribution shows significant morbidity differences between regions, especially between eastern and western Germany. However, the cohort-referenced estimates suggest that these differences can be partially explained by regional demography.ConclusionsThe proposed methodology allows regional prevalence estimation in remarkable detail despite fund-specific selectivity. This enhances and encourages the use of health insurance records for future epidemiologic studies.