Effect Modification of Sex and Age for the Hospital Volume-Outcome Relationship in Abdominal Aortic Aneurysm Treatment: Secondary Data Analysis of the Nationwide German Diagnosis Related Groups Statistics From 2005 to 2014

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

OBJECTIVE

Abdominal aortic aneurysm rupture (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 seasonal, weekday, and daytime fluctuations of the hospital incidence, treatment modalities, and outcomes of rAAA, based on the most recent nationwide German real world data.

METHODS

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.

RESULTS

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%). Multivariable analyses revealed higher mortality rates on Mondays and Sundays. On a daytime basis, lower EVAR rates and higher mortality rates were found during the 16:00 - 8:00 period.

CONCLUSION

In German hospitals, incidences and EVAR rates to treat rAAA were lowest on Mondays and Sundays. The associated overall mortality rates were highest on the respective days. Further restructuring and centralisation of AAA treatment in Germany could potentially mitigate this weekday effect.

A Bibliometric Analysis of Diagnosis Related Groups from 2013 to 2022

Purpose

As an important management method of the global healthcare system, diagnosis related groups (DRGs) classify patients into different cost groups and pay more attention to the equitable distribution of medical resources and the quality of medical services. At present, most countries have used DRGs to help medical institutions and doctors to treat patients more accurately, avoid the waste of medical resources, and improve treatment efficiency.

Methods

The Web of Science database was searched to collect all relevant literature on DRGs from 2013 to 2022. The literature information was imported into CiteSpace, Vosviewer, and Histcite for data analysis and visualization of the results. Analyze the cooperative relationship among the countries, institutions, journals, and authors. The usage trend of keywords; Highlight the content of the cited articles.

Results

The number of articles published in this decade was stable, and the number of citations in 2014 was the highest. The United States and Germany, as the first countries to use the DRGs system, are ahead of other countries in terms of the number and quality of articles. We have carried out content research on the articles with high citations, and summarized the application range of DRGs; classification method; advantages and disadvantages of the application. In general, the development trend of DRGs in foreign countries is to continuously optimize the classification method, expand the scope of application, and improve the application effect. These provide support and reference for the improvement of medical services and the perfection of the medical insurance system.

Conclusion

The application of DRGs can improve the quality and efficiency of medical services, and reduce the waste of medical expenses. It can also promote the rational allocation of medical resources and the equity of medical services. In the future, DRGs will pay more attention to the personalized diagnosis and treatment and fine management of patients, and the sharing and standardization of medical data, to promote the development of medical informatization.

Translating mouse models of abdominal aortic aneurysm to the translational needs of vascular surgery

Introduction

Abdominal aortic aneurysm (AAA) is a condition that has considerable socioeconomic impact and an eventual rupture is associated with high mortality and morbidity. Despite decades of research, surgical repair remains the treatment of choice and no medical therapy is currently available. Animal models and, in particular, murine models, of AAA are a vital tool for experimental in vivo research. However, each of the different models has individual limitations and provide only partial mimicry of human disease. This narrative review addresses the translational potential of the available mouse models, highlighting unanswered questions from a clinical perspective. It is based on a thorough presentation of the available literature and more than a decade of personal experience, with most of the available models in experimental and translational AAA research.

Results

From all the models published, only the four inducible models, namely the angiotensin II model (AngII), the porcine pancreatic elastase perfusion model (PPE), the external periadventitial elastase application (ePPE), and the CaCl₂ model have been widely used by different independent research groups. Although the angiotensin II model provides features of dissection and aneurysm formation, the PPE model shows reliable features of human AAA, especially beyond day 7 after induction, but remains technically challenging. The translational value of ePPE as a model and the combination with β-aminopropionitrile to induce rupture and intraluminal thrombus formation is promising, but warrants further mechanistic insights. Finally, the external CaCl₂ application is known to produce inflammatory vascular wall thickening. Unmet translational research questions include the origin of AAA development, monitoring aneurysm growth, gender issues, and novel surgical therapies as well as novel nonsurgical therapies.

Conclusion

New imaging techniques, experimental therapeutic alternatives, and endovascular treatment options provide a plethora of research topics to strengthen the individual features of currently available mouse models, creating the possibility of shedding new light on translational research questions.

A systematic review and meta-analysis on early mortality after abdominal aortic aneurysm repair in females in urgent and elective setting

OBJECTIVE

Females represent a group of patients with higher mortality after abdominal aortic aneurysm (AAA), endovascular (EVAR) or open (OSR), repair. This systematic review aimed to evaluate the 30-day mortality after AAA repair in females, comparing both EVAR and OSR, in elective and urgent settings.

METHODS

The protocol of the review was registered to the PROSPERO (CRD42021242686). A search of the English literature was conducted, using PubMed, EMBASE and CENTRAL databases, from inception to March 5, 2021, using the Systematic Reviews and Meta-Analysis guidelines (PRISMA). Only studies reporting on 30-day mortality of AAA repair, in urgent and elective setting, comparing EVAR and OSR, in female population were eligible. Patients were stratified according to the need for elective or urgent repair. Symptomatic and ruptured cases were included into the urgent group. Individual studies were assessed for risk of bias using the ROBINS-I tool. The GRADE approach was used to evaluate the quality of evidence. The primary outcome was 30-day mortality after AAA repair in the female population, comparing EVAR and OSR. The outcomes were summarized as odds ratio along with their 95% confidence intervals (CI), through a paired meta-analysis.

RESULTS

Eight studies reported data on 30-day mortality following AAA repair. A total of 56,982 females (22,995 EVAR vs. 33,987 OSR) were included. A significantly reduced total 30-day mortality rate was recorded among females that underwent EVAR compared to OSR (OR, 0.25; 95% CI, 0.23-0.27; P<.001, Ι²=86%). Also a reduced 30-day mortality was found in females that underwent elective EVAR compared to OSR (OR, 0.37; 95% CI, 0.33-0.41; P< .001, Ι²=48%). Despite that OSR was more frequently offered in the urgent setting (OR, 0.21; 95% CI, 0.19-0.23; P< .001, Ι²=84%), EVAR was associated with a reduced 30-day mortality (OR, 0.48; 95% CI, 0.40-0.57; P<.001, Ι²=0%).

CONCLUSIONS

In females, EVAR is associated with lower 30-day mortality in both elective and urgent AAA repair, although it appears as less likely to be offered in the setting of urgent AAA repair.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Effect Modification of Sex and Age for the Hospital Volume-Outcome Relationship in Abdominal Aortic Aneurysm Treatment: Secondary Data Analysis of the Nationwide German Diagnosis Related Groups Statistics From 2005 to 2014

Background Trials and registries associated female sex and high age with unfavorable outcomes in abdominal aortic aneurysm treatment. Many studies showed an inverse correlation between annual hospital volume and in-hospital mortality. The volume-outcome relationship has not been investigated separately for women and men or across the age range. The aim was to analyze whether sex and age are effect modifiers or confounders of the volume-outcome association. Methods and Results In a nationwide setting, all in-hospital cases from 2005 to 2014 with a diagnosis of intact abdominal aortic aneurysm and procedure codes for endovascular or open aortic repair were included. Primary outcome was in-hospital mortality. Using a multilevel multivariable regression model, hospital volume was modeled as a continuous variable. Separate analyses were performed for women and men and for predefined age groups. A total of 94 966 cases were included (12% women; median age, 72 years). Mortality was 4.9% in women and 3.0% in men (3.2% overall). Mortality increased with age. Although there was no significant volume-outcome association in women (P=0.57), there was in men (P=0.02). The strongest volume-outcome association was found in younger men. The younger female subpopulation was found to show a trend for an inverse volume-outcome relationship, whereas an opposite association was found for the women aged >79 years. Conclusions Women have a higher mortality risk after elective abdominal aortic aneurysm treatment. Sex and age are modifiers of the volume-outcome relationship. Unlike in male patients, in women there is no consistent effect of hospital volume on outcome.