Association of joint replacement surgery with incident dementia diagnosis in German claims data

An exploratory research report on brain mineralization in postoperative delirium and cognitive decline

Delirium is a severe postoperative complication associated with poor overall and especially neurocognitive prognosis. Altered brain mineralization is found in neurodegenerative disorders but has not been studied in postoperative delirium and postoperative cognitive decline. We hypothesized that mineralization-related hypointensity in susceptibility-weighted magnetic resonance imaging (SWI) is associated with postoperative delirium and cognitive decline. In an exploratory, hypothesis-generating study, we analysed a subsample of cognitively healthy patients ≥65 years who underwent SWI before (N = 65) and 3 months after surgery (N = 33). We measured relative SWI intensities in the basal ganglia, hippocampus and posterior basal forebrain cholinergic system (pBFCS). A post hoc analysis of two pBFCS subregions (Ch4, Ch4p) was conducted. Patients were screened for delirium until the seventh postoperative day. Cognitive testing was performed before and 3 months after surgery. Fourteen patients developed delirium. After adjustment for age, sex, preoperative cognition and region volume, only pBFCS hypointensity was associated with delirium (regression coefficient [90% CI]: B = -15.3 [-31.6; -0.8]). After adjustments for surgery duration, age, sex and region volume, perioperative change in relative SWI intensities of the pBFCS was associated with cognitive decline 3 months after surgery at a trend level (B = 6.8 [-0.9; 14.1]), which was probably driven by a stronger association in subregion Ch4p (B = 9.3 [2.3; 16.2]). Brain mineralization, particularly in the cerebral cholinergic system, could be a pathomechanism in postoperative delirium and cognitive decline. Evidence from our studies is limited because of the small sample and a SWI dataset unfit for iron quantification, and the analyses presented here should be considered exploratory.

Dementia Development during Long-Term Follow-Up after Surgical Aortic Valve Replacement with a Biological Prosthesis in a Geriatric Population

Surgical aortic valve replacement (SAVR) with a biological heart valve prosthesis (BHV) is often used as a treatment in elderly patients with symptomatic aortic valve disease. This age group is also at risk for the development of dementia in the years following SAVR. The research question is "what are the predictors for the development of dementia?". In 1500 patients undergoing SAVR with or without an associated procedure, preoperative (demographic, cardiac and non-cardiac comorbid conditions), perioperative (associated procedures, cross-clamp and cardiopulmonary bypass time) and postoperative 30-day adverse events (bleeding, thromboembolism, heart failure, conduction defects, arrhythmias, delirium, renal and pulmonary complications) were investigated for their effect on the occurrence of dementia by univariate analyses. Significant factors were entered in a multivariate analysis. The sum of the individual follow-up of the patients was 10,182 patient-years, with a mean follow-up of 6.8 years. Data for the development of dementia could be obtained in 1233 of the 1406 patients who left the hospital alive. Dementia during long-term follow-up developed in 216/1233 (17.2%) of the patients at 70 ± 37 months. Development of dementia reduced the mean survival from 123 (119-128) to 109 (102-116) months (p < 0.001). Postoperative delirium was the dominant predictor (OR = 3.55 with a 95%CI of 2.41-4.93; p < 0.00), followed by age > 80 years (2.38; 1.78-3.18; p < 0.001); preoperative atrial fibrillation (1.47; 1.07-2.01; p = 0.018); cardiopulmonary bypass time > 120 min (1.34; 1.02-1.78; p = 0.039) and postoperative thromboembolism (1.94; 1.02-3.70; p = 0.044). Postoperative delirium, as a marker for poor condition, and an age of 80 or more were the dominant predictors.

Dementia risk predictions from German claims data using methods of machine learning

INTRODUCTION

We examined whether German claims data are suitable for dementia risk prediction, how machine learning (ML) compares to classical regression, and what the important predictors for dementia risk are.

METHODS

We analyzed data from the largest German health insurance company, including 117,895 dementia-free people age 65+. Follow-up was 10 years. Predictors were: 23 age-related diseases, 212 medical prescriptions, 87 surgery codes, as well as age and sex. Statistical methods included logistic regression (LR), gradient boosting (GBM), and random forests (RFs).

RESULTS

Discriminatory power was moderate for LR (C-statistic = 0.714; 95% confidence interval [CI] = 0.708-0.720) and GBM (C-statistic = 0.707; 95% CI  = 0.700-0.713) and lower for RF (C-statistic = 0.636; 95% CI  = 0.628-0.643). GBM had the best model calibration. We identified antipsychotic medications and cerebrovascular disease but also a less-established specific antibacterial medical prescription as important predictors.

DISCUSSION

Our models from German claims data have acceptable accuracy and may provide cost-effective decision support for early dementia screening.

[Planning revision hip arthroplasty : What are the structural requirements?]

The results of many studies and register reports show that the frequency of primary hip arthroplasty per hospital, but also per surgeon, influence the outcome. In the large spectrum of revision hip arthroplasty volume-outcome effects have also partially been proven. It is obvious that with the increasing complexity of revision surgery and comorbidities, higher demands exist concerning collaborating disciplines as well as training and intervention frequency of the surgical team. Further aspects regarding organisation and structure such as the availability of specific revision implants and instruments must be ensured. In order to provide sustainable resources for revision surgery in an arthroplasty centre, organization of education and training for staff members in different disciplines and working levels must be ensured without quality impairment.

Postoperative Delirium Following Joint Replacement in Patients With Dementia in New South Wales, Australia: A State-Wide Retrospective Cohort Study

The objective of the current study was to investigate the variation in postoperative delirium in patients with dementia undergoing joint replacement in New South Wales (NSW) Australia public hospitals, identify factors related to its occurrence, and explore the volume-outcome relationship. The NSW Admitted Patient Data (July 2001 to June 2014) were used in this study and included patients with dementia undergoing joint replacement who were 65 or older with minor to severe comorbidities. Mixed-effect logistic models were applied to investigate hospital-level variation and factors associated with postoperative delirium. The between-hospital variability of postoperative delirium was 0.19% prior to 2008-2009 and 8.32% after 2008-2009. Hospital volume was not inversely associated with postoperative delirium rate. During 2001-2014, the incidence of postoperative delirium increased by 13% per annum (95% confidence interval [CI] 10% to 16%), while it increased by 15% per annum (95% CI 8% to 22%) after 2008-2009. An integrated approach addressing complex needs of patients with dementia may reduce the observed unwarranted variation and improve surgical outcomes. [Research in Gerontological Nursing, 13(5), 243-253.].

Relationship between Surgery under General Anesthesia and the Development of Dementia: A Systematic Review and Meta-Analysis

Objective

To investigate the association between exposure to general anesthesia and the development of Alzheimer's disease (AD) and dementia by reviewing and integrating the evidence from epidemiological studies published to date.

Methods

We searched MEDLINE, EMBASE, and Google Scholar to identify all relevant articles up to April 2018 reporting the risk of AD/dementia following exposure to general anesthesia and finally updated in February 2020. We included patients older than 60 or 65 years who had not been diagnosed with dementia or AD before the study period. The overall pooled effect size (ES) was evaluated with a random-effect model. Subgroup analyses were conducted and possibility of publication bias was assessed.

Results

A total of 23 studies with 412253 patients were included in our analysis. A statistically significant positive association between exposure to general anesthesia and the occurrence of AD was detected in the overall analysis (pooled ES = 1.11, 95%confidence interval = 1.07–1.15), but with substantial heterogeneity (p_χ² < 0.001, I² = 79.4). Although the overall analysis revealed a significant association, the results of the subgroup analyses were inconsistent, and the possibility of publication bias was detected.

Conclusion

s. This meta-analysis demonstrated a significant positive association between general anesthesia and AD. However, considering other results, our meta-analysis must be interpreted with caution. Particularly, it should be considered that it was nearly impossible to discriminate the influence of general anesthesia from the effect of surgery itself on the development of AD. Further, large-scale studies devised to reduce the risk of bias are needed to elucidate the evidence of association between general anesthesia and AD. Trial registration. PROSPERO International prospective register of systematic reviews CRD42017073790.