Meta-Analysis of Diagnostic Accuracy Studies With Multiple Thresholds: Comparison of Approaches in a Simulation Study.

The development of methods for the meta-analysis of diagnostic test accuracy (DTA) studies is still an active area of research. While methods for the standard case where each study reports a single pair of sensitivity and specificity are nearly routinely applied nowadays, methods to meta-analyze receiver operating characteristic (ROC) curves are not widely used. This situation is more complex, as each primary DTA study may report on several pairs of sensitivity and specificity, each corresponding to a different threshold. In a case study published earlier, we applied a number of methods for meta-analyzing DTA studies with multiple thresholds to a real-world data example (Zapf et al., Biometrical Journal. 2021; 63(4): 699-711). To date, no simulation study exists that systematically compares different approaches with respect to their performance in various scenarios when the truth is known. In this article, we aim to fill this gap and present the results of a simulation study that compares three frequentist approaches for the meta-analysis of ROC curves. We performed a systematic simulation study, motivated by an example from medical research. In the simulations, all three approaches worked partially well. The approach by Hoyer and colleagues was slightly superior in most scenarios and is recommended in practice.

A discrete time-to-event model for the meta-analysis of full ROC curves.

The development of new statistical models for the meta-analysis of diagnostic test accuracy studies is still an ongoing field of research, especially with respect to summary receiver operating characteristic (ROC) curves. In the recently published updated version of the "Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy", the authors point to the challenges of this kind of meta-analysis and propose two approaches. However, both of them come with some disadvantages, such as the nonstraightforward choice of priors in Bayesian models or the requirement of a two-step approach where parameters are estimated for the individual studies, followed by summarizing the results. As an alternative, we propose a novel model by applying methods from time-to-event analysis. To this task we use the discrete proportional hazard approach to treat the different diagnostic thresholds, that provide means to estimate sensitivity and specificity and are reported by the single studies, as categorical variables in a generalized linear mixed model, using both the logit- and the asymmetric cloglog-link. This leads to a model specification with threshold-specific discrete hazards, avoiding a linear dependency between thresholds, discrete hazard, and sensitivity/specificity and thus increasing model flexibility. We compare the resulting models to approaches from the literature in a simulation study. While the estimated area under the summary ROC curve is estimated comparably well in most approaches, the results depict substantial differences in the estimated sensitivities and specificities. We also show the practical applicability of the models to data from a meta-analysis for the screening of type 2 diabetes.

Association of plasma proteomics with mortality in individuals with and without type 2 diabetes: Results from two population-based KORA cohort studies.

BACKGROUND: Protein biomarkers may contribute to the identification of vulnerable subgroups for premature mortality. This study aimed to investigate the association of plasma proteins with all-cause and cause-specific mortality among individuals with and without baseline type 2 diabetes (T2D) and evaluate their impact on the prediction of all-cause mortality in two prospective Cooperative Health Research in the Region of Augsburg (KORA) studies. METHODS: The discovery cohort comprised 1545 participants (median follow-up 15.6 years; 244 with T2D: 116 total, 62 cardiovascular, 31 cancer-related and 23 other-cause deaths; 1301 without T2D: 321 total, 114 cardiovascular, 120 cancer-related and 87 other-cause deaths). The validation cohort comprised 1031 participants (median follow-up 6.9 years; 203 with T2D: 76 total, 45 cardiovascular, 19 cancer-related and 12 other-cause deaths; 828 without T2D: 169 total, 74 cardiovascular, 39 cancer-related and 56 other-cause deaths). We used Cox regression to examine associations of 233 plasma proteins with all-cause and cause-specific mortality and Lasso regression to construct prediction models for all-cause mortality stratifying by baseline T2D. C-index, category-free net reclassification index (cfNRI), and integrated discrimination improvement (IDI) were conducted to evaluate the predictive performance of built prediction models. RESULTS: Thirty-five and 62 proteins, with 29 overlapping, were positively associated with all-cause mortality in the group with and without T2D, respectively. Out of these, in the group with T2D, 35, eight, and 26 were positively associated with cardiovascular, cancer-related, and other-cause mortality, while in the group without T2D, 55, 41, and 47 were positively associated with respective cause-specific outcomes in the pooled analysis of both cohorts. Regulation of insulin-like growth factor (IGF) transport and uptake by IGF-binding proteins emerged as a unique pathway enriched for all-cause and cardiovascular mortality in individuals with T2D. The combined model containing the selected proteins (five and 12 proteins, with four overlapping, in the group with and without T2D, respectively) and clinical risk factors improved the prediction of all-cause mortality by C-index, cfNRI, and IDI. CONCLUSIONS: This study uncovered shared and unique mortality-related proteins in persons with and without T2D and emphasized the role of proteins in improving the prediction of mortality in different T2D subgroups.

[Prehospital analgesia with nalbuphine and paracetamol compared to piritramide by paramedics-A multicenter observational study]. / Prähospitale Analgesie mit Nalbuphin und Paracetamol im Vergleich zu Piritramid durch Notfallsanitäter*innen ­ eine multizentrische Observationsstudie.

OBJECTIVE: Following recent changes to the German Narcotics Act, this article examines prehospital analgesia by paramedics using piritramide vs. nalbuphine + paracetamol. MATERIAL AND METHODS: Prehospital analgesia administered by paramedics from the Fulda (piritramide) and Gütersloh (nalbuphine + paracetamol) emergency services was compared regarding pain intensity at the beginning and end of the mission, measured using the numeric rating scale (NRS). Additionally, an analysis of the resulting complications was carried out. RESULTS: In this study 2429 administrations of analgesia were evaluated (nalbuphine + paracetamol: 1635, 67.3%, initial NRS: 8.0 ± 1.4, end of NRS: 3.7 ± 2.0; piritramide: 794, 32.7%, initial NRS: 8.5 ± 1.1, end of NRS: 4.5 ± 1.6). Factors influencing NRS change were initial NRS (regression coefficient, RC: 0.7075, 95% confidence interval, CI: 0.6503-0.7647, p < 0.001), treatment with nalbuphine + paracetamol (RC: 0.6048, 95% CI: 0.4396-0.7700, p < 0.001). Treatment with nalbuphine + paracetamol (n = 796 (48.7%)) compared to piritramide (n = 190 (23.9%)) increased the odds of achieving NRS < 4 (odds ratio, OR: 2.712, 95% CI: 2.227-3.303, p < 0.001). Complications occurred in n = 44 (5.5%) with piritramide and in n = 35 (2.1%) with nalbuphine + paracetamol. Risk factors for complications were analgesia with piritramide (OR: 2.699, 95% CI: 1.693-4.301, p < 0.001), female sex (OR: 2.372, 95% CI: 1.396-4.029, p = 0.0014), and age (OR: 1.013, 95% CI: 1.002-1.025, p = 0.0232). CONCLUSION: Compared with piritramide, prehospital analgesia with nalbuphine + paracetamol has favorable effects in terms of analgesic efficacy and complication rates and should therefore be considered in future recommendations for paramedics.

Using the illness-death model to estimate age- and sex-standardized incidence rates of diabetes in Mexico from 2003 to 2015.

BACKGROUND: We aimed to estimate the age-specific and age-standardized incidence rate of diabetes for men and women in Mexico between 2003 and 2015, and to assess the relative change in incidence of diabetes between 2003 and 2015. METHODS: We use a partial differential equation describing the illness-death model to estimate the incidence rate (IR) of diabetes for the years 2003, 2009 and 2015 based on prevalence data from National Health Surveys conducted in Mexico, the mortality rate of the Mexican general population and plausible input values for age-specific mortality rate ratios associated with diabetes. RESULTS: The age-standardized IR of diabetes per 1000 person years (pryr) was similar among men (IRm) and women (IRw) in the year 2003 (IRm 6.1 vs. IRw 6.5 1000/pryr), 2009 (IRm: 7.0 vs. IRw: 8.4 1000/pryr), and in 2015 (IRm 8.0 vs. IRw 10.6 1000/pryr). The highest incident rates were observed among men and women in the 60-69 age group. CONCLUSIONS: Overall, the incidence rate of diabetes in Mexico between the years 2003 and 2015 remained stable. However, rates were markedly higher among women in the age group 40-49 and 50-59 in the year 2015 compared with rates in 2003.

Projected number of people with multiple sclerosis in Germany between 2015 and 2040.

BACKGROUND: The global prevalence of multiple sclerosis has shown a marked rise in recent decades, with Germany reporting the highest prevalence among European countries. This study aims to project the future number of people with multiple sclerosis in Germany until 2040 which is necessary for effective resource allocation and health care planning. METHODS: Based on data from the German statutory health insurance, the age- and sex-specific prevalence of multiple sclerosis was estimated applying mathematical relations between prevalence, incidence rate, and mortality rate. Subsequently, the projected prevalence was applied to the age structure of the German population between 2015 and 2040 to calculate the future number of people with multiple sclerosis. Several temporal trend scenarios pertaining to the incidence and mortality rate were compared. RESULTS: Application of current age-specific prevalence estimates combined with the projected population structure in 2040, results in a decline of 8% in the number of people with multiple sclerosis. More realistic scenarios that reflect on trends in mortality and incidence rates, project between 453,000 (+75%) and 477,000 (+85%) multiple sclerosis cases in 2040. It is expected that females will be affected nearly 2.5 times more frequently than males in 2040. CONCLUSION: The findings indicate a substantial rise in the prevalence of multiple sclerosis, ranging from 75% to 85% in 2040 compared to 2015. Assuming a constant age-specific prevalence between 2015 and 2040 without any temporal trends in mortality and incidence rates may underestimate the actual number of cases and consequently, future requirements for healthcare resources.

Projecting the economic burden of type 1 and type 2 diabetes mellitus in Germany from 2010 until 2040.

BACKGROUND: The aim is to estimate age- and sex-specific direct medical costs related to diagnosed type 1 and type 2 diabetes in Germany between 2010 and 2040. METHODS: Based on nationwide representative epidemiological routine data from 2010 from the statutory health insurance in Germany (almost 80% of the population's insurance) we projected age- and sex-specific healthcare expenses for type 1 and 2 diabetes considering future demographic, disease-specific and cost trends. We combine per capita healthcare cost data (obtained from aggregated claims data from an almost 7% random sample of all German people with statutory health insurance) together with the demographic structure of the German population (obtained from the Federal Statictical Office), diabetes prevalence, incidence and mortality. Direct per capita costs, total annual costs, cost ratios for people with versus without diabetes and attributable costs were estimated. The source code for running the analysis is publicly available in the open-access repository Zenodo. RESULTS: In 2010, total healthcare costs amounted to more than €1 billion for type 1 and €28 billion for type 2 diabetes. Depending on the scenario, total annual expenses were projected to rise remarkably until 2040 compared to 2010, by 1-281% for type 1 (€1 to €4 billion) and by 8-364% for type 2 diabetes (€30 to €131 billion). In a relatively probable scenario total costs amount to about €2 and €79 billion for type 1 and type 2 diabetes in 2040, respectively. Depending on annual cost growth (1% p.a. as realistic scenario vs. 5% p.a. as very extreme setting), we estimated annual per capita costs of €6,581 to €12,057 for type 1 and €5,245 to €8,999 for type 2 diabetes in 2040. CONCLUSIONS: Diabetes imposes a large economic burden on Germany which is projected to increase substantially until 2040. Temporal trends in the incidence and cost growth are main drivers of this increase. This highlight the need for urgent action to prepare for the potential development and mitigate its consequences.

[Analysis of factors influencing outpatient paediatric antibiotic prescriptions in Bielefeld from 2015 to 2018]. / Analyse von Einflussfaktoren auf ambulante pädiatrische Antibiotikaverordnungen in Bielefeld 2015­2018.

BACKGROUND: There are significant regional differences in antibiotic prescribing behaviour. The reasons for this are still largely unknown. Beneath demographic and morbidity-related factors, doctor-specific or "cultural" factors may also play a role. A differentiated analysis including diagnostic data is needed to put these data into context. METHODS: A data analysis with secondary data available via the Westphalia-Lippe Association of Statutory Health Insurance Physicians (KVWL) was conducted on infection diagnoses and antibiotic prescriptions of outpatient paediatricians in the KV district of Bielefeld from 2015 to 2018. In addition, algorithmized 1:1 connections between diagnoses and prescriptions were performed. RESULTS: For 262,969 "medication patients" (AMP), 28,248 antibiotic prescriptions and 90,044 infection diagnoses were evaluated, from which 11,131 1:1 connections could be generated. Concerning the prescribing behaviour of individual paediatric GP offices, after adjusting for the denominator AMP and despite a comparable age and gender structure, there were some significant differences. This affected both the frequency of prescriptions and the qualitative composition of the substance groups prescribed. DISCUSSION: The differences in antibiotic prescribing behaviour, even at GP office level, cannot be adequately explained by the demographic composition or different morbidities of the respective clientele. Individual attitudes and local prescribing cultures are likely to play a relevant role. To address these offers an important approach for antibiotic stewardship (ABS). In addition to the area of outpatient paediatrics presented here, the methodology described can also be used as a model for more detailed analysis in other outpatient speciality groups.

Injection of Autologous Adipose Stromal Vascular Fraction in Combination with Autologous Conditioned Plasma for the Treatment of Advanced Knee Osteoarthritis Significantly Improves Clinical Symptoms.

(1) Background: Osteoarthritis (OA) is the most common joint disease in the world. It is chronic, systemic, progressive and disabling. Orthobiologics have the potential to positively alter the course of this disease. Therefore, the aim of this study is to evaluate the efficacy of SVF/ACP in the treatment of advanced osteoarthritis of the knee in an unfiltered patient population. We hypothesize that this therapy can improve the symptoms associated with osteoarthritis of the knee. We also hypothesize that there are patient-related factors that influence the efficacy of therapy. (2) Methods: Two hundred and thirteen patients with moderate to severe OA of the knee and SVF/ACP injection were recruited for this study. Patients were excluded if they did not provide informed consent or were not receiving SVF/ACP therapy. Pain, function, symptoms and quality of life were assessed using standardized scores (KOOS, WOMAC) before and after treatment. (3) Results: The VAS pain score was significantly reduced by at least 30% (p < 0.001). Knee function, as measured by the KOOS daily activity and sport scores, showed significant increases of 21% and 45%, respectively, at 6 months (p < 0.04). (4) Conclusions: Treatment of knee OA with SVF/ACP injection positively modifies the disease by significantly reducing pain and improving function.

Safety of magnetic resonance imaging in patients with cardiac implantable electronic devices and abandoned or epicardial leads: a systematic review and meta-analysis.

AIMS: Persistent reluctance to perform magnetic resonance imaging (MRI) in patients with abandoned and/or epicardial leads of cardiac implantable electronic devices is related to in vitro studies reporting tip heating. While there is a plethora of data on the safety of MRI in conditional and non-conditional implantable devices, there is a clear lack of safety data in patients with abandoned and/or epicardial leads. METHODS AND RESULTS: Relevant literature was identified in Medline and CINAHL using the key terms 'magnetic resonance imaging' AND 'abandoned leads' OR 'epicardial leads'. Secondary literature and cross-references were supplemented. For reporting guidance, the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 was used. International Prospective Register of Systematic Reviews (PROSPERO) registration number 465530. Twenty-one publications with a total of 656 patients with 854 abandoned and/or epicardial leads and 929 MRI scans of different anatomical regions were included. No scan-related major adverse cardiac event was documented, although the possibility of under-reporting of critical events in the literature should be considered. Furthermore, no severe device dysfunction or severe arrhythmia was reported. Mainly transient lead parameter changes were observed in 2.8% in the subgroup of patients with functional epicardial leads. As a possible correlate of myocardial affection, subjective sensations occurred mainly in the subgroup with abandoned epicardial leads (4.0%), but no change in myocardial biomarkers was observed. CONCLUSION: Existing publications did not report any relevant adverse events for MRI in patients with abandoned and/or epicardial leads if performed according to strict safety guidelines. However, a more rigorous risk-benefit calculation should be made for patients with epicardial leads.

Trends in incidence and mortality of early-onset cancer in Germany between 1999 and 2019.

Evidence on the recent temporal trend in the incidence and mortality of early-onset cancer, i.e., cancer diagnosed at ages of < 50 years, in Germany is scarce. To estimate the temporal trend in the incidence and mortality of early-onset cancer in Germany between 1999 and 2019. Input data were obtained from the Centre for Cancer Registry Data (Zentrum für Krebsregisterdaten, ZfKD). The analysis comprised all ages until 50 years and all types of cancer classified by the International Classification of Diseases (ICD-10)-codes C00-C97 (excl. C44). Temporal trends were estimated using negative binomial regression, differentiated by sex and cancer type. Between 1999 and 2019 in Germany, we observed stable or slightly increasing trends (0% and 1%) in the incidence of all early-onset cancers combined (C00-C97) for men and women, respectively, and strict declines in the mortality for both, men and women (-2% and - 3%). However, the trends differ largely with respect to sex and the individual cancer types. Early-onset cancer should be closely monitored to see whether stable and decreasing trends in the incidence and mortality continue. Knowing that despite decreasing incidence, the prevalence of a disease can rise due to their interplay with mortality, we recommend to maintain precise surveillance, efforts in prevention and early detection, as well as appropriate investments into healthcare resources, research and development.

Effectiveness and safety of prehospital analgesia with nalbuphine and paracetamol versus morphine by paramedics - an observational study.

BACKGROUND: Despite the development of various analgesic concepts, prehospital oligoanalgesia remains very common. The present work examines prehospital analgesia by paramedics using morphine vs. nalbuphine + paracetamol. METHODS: Patients with out-of-hospital-analgesia performed by paramedics from the emergency medical services of the districts of Fulda (morphine) and Gütersloh (nalbuphine + paracetamol) were evaluated with regards to pain intensity at the beginning and the end of prehospital treatment using the Numeric-Rating-Scale for pain (NRS), sex, age, and complications. The primary endpoint was achievement of adequate analgesia, defined as NRS < 4 at hospital handover, depending on the analgesics administered (nalbuphine + paracetamol vs. morphine). Pain intensity before and after receiving analgesia using the NRS, sex, age and complications were also monitored. RESULTS: A total of 1,808 patients who received out-of-hospital-analgesia were evaluated (nalbuphine + paracetamol: 1,635 (90.4%), NRS-initial: 8.0 ± 1.4, NRS-at-handover: 3.7 ± 2.0; morphine: 173(9.6%), NRS-initial: 8.5 ± 1.1, NRS-at-handover: 5.1 ± 2.0). Factors influencing the difference in NRS were: initial pain intensity on the NRS (regression coefficient (RK): 0.7276, 95%CI: 0.6602-0.7950, p < 0.001), therapy with morphine vs. nalbuphine + paracetamol (RK: -1.2594, 95%CI: -1.5770 - -0.9418, p < 0.001) and traumatic vs. non-traumatic causes of pain (RK: -0.2952, 95%CI: -0.4879 - -0.1024, p = 0.002). Therapy with morphine (n = 34 (19.6%)) compared to nalbuphine + paracetamol (n = 796 (48.7%)) (odds ratio (OR): 0.274, 95%CI: 0.185-0.405, p < 0.001) and the initial NRS score (OR:0.827, 95%CI: 0.771-0.887, p < 0.001) reduced the odds of having an NRS < 4 at hospital handover. Complications occurred with morphine in n = 10 (5.8%) and with nalbuphine + paracetamol in n = 35 (2.1%) cases. Risk factors for complications were analgesia with morphine (OR: 2.690, 95%CI: 1.287-5.621, p = 0.008), female sex (OR: 2.024, 95%CI: 1.040-3.937, p = 0.0379), as well as age (OR: 1.018, 95%CI: 1.003-1.034, p = 0.02). CONCLUSIONS: Compared to morphine, prehospital analgesia with nalbuphine + paracetamol yields favourable effects in terms of analgesic effectiveness and a lower rate of complications and should therefore be considered in future recommendations for prehospital analgesia.

A nonparametric proportional risk model to assess a treatment effect in time-to-event data.

Time-to-event analysis often relies on prior parametric assumptions, or, if a semiparametric approach is chosen, Cox's model. This is inherently tied to the assumption of proportional hazards, with the analysis potentially invalidated if this assumption is not fulfilled. In addition, most interpretations focus on the hazard ratio, that is often misinterpreted as the relative risk (RR), the ratio of the cumulative distribution functions. In this paper, we introduce an alternative to current methodology for assessing a treatment effect in a two-group situation, not relying on the proportional hazards assumption but assuming proportional risks. Precisely, we propose a new nonparametric model to directly estimate the RR of two groups to experience an event under the assumption that the risk ratio is constant over time. In addition to this relative measure, our model allows for calculating the number needed to treat as an absolute measure, providing the possibility of an easy and holistic interpretation of the data. We demonstrate the validity of the approach by means of a simulation study and present an application to data from a large randomized controlled trial investigating the effect of dapagliflozin on all-cause mortality.

Prehospital anesthesia in postcardiac arrest patients: a multicenter retrospective cohort study.

BACKGROUND: Currently, the data regarding the impact of prehospital postcardiac arrest anesthesia on target hemodynamic and ventilatory parameters of early postresuscitation care and recommendations on its implementation are rare. The present study examines the incidence and impact of prehospital postcardiac arrest anesthesia on hemodynamic and ventilatory target parameters of postresuscitation care. METHODS: In this multicentre observational study between 2019 and 2021 unconscious adult patients after out-of-hospital-cardiac arrest with the presence of a return-of-spontaneous circulation until hospital admission were included. Primary endpoint was the application of postarrest anesthesia. Secondary endpoints included the medication group used, predisposing factors to its implementation, and its influence on achieving target parameters of postresuscitation care (systolic blood pressure: ≥ 100 mmHg, etCO2:35-45 mmHg, SpO2: 94-98%) at hospital handover. RESULTS: During the study period 2,335 out-of-hospital resuscitations out of 391,305 prehospital emergency operations (incidence: 0.58%; 95% CI 0.54-0.63) were observed with a return of spontaneous circulation to hospital admission in 706 patients (30.7%; 95% CI 28.8-32.6; female: 34.3%; age:68.3 ± 14.2 years). Postcardiac arrest anesthesia was performed in 482 patients (68.3%; 95% CI 64.7-71.7) with application of hypnotics in 93.4% (n = 451), analgesics in 53.7% (n = 259) and relaxants in 45.6% (n = 220). Factors influencing postcardiac arrest sedation were emergency care by an anesthetist (odds ratio: 2.10; 95% CI 1.34-3.30; P < 0.001) and treatment-free interval ≤ 5 min (odds ratio: 1.59; 95% CI 1.01-2.49; P = 0.04). Although there was no evidence of the impact of performing postcardiac arrest anesthesia on achieving a systolic blood pressure ≥ 100 mmHg at the end of operation (odds ratio: 1.14; 95% CI 0.78-1.68; P = 0.48), patients with postcardiac arrest anesthesia were significantly more likely to achieve the recommended ventilation (odds ratio: 1.59; 95% CI 1.06-2.40; P = 0.02) and oxygenation (odds ratio:1.56; 95% CI 1.04-2.35; P = 0.03) targets. Comparing the substance groups, the use of hypnotics significantly more often enabled the target values for etCO2 to be reached alone (odds ratio:2.79; 95% CI 1.04-7.50; P = 0.04) as well as in combination with a systolic blood pressure ≥ 100 mmHg (odds ratio:4.42; 95% CI 1.03-19.01; P = 0.04). CONCLUSIONS: Postcardiac arrest anesthesia in out-of-hospital cardiac arrest is associated with early achievement of respiratory target parameters in prehospital postresuscitation care without evidence of more frequent hemodynamic complications.

Effects of COVID-19 on a mature citizen first responder system in the German district of Gütersloh: an observational study.

BACKGROUND: The aim of this study was to examine the impact of COVID-19 on the response rate of community-first-responders (CFR) and other out-of-hospital-cardiac-arrest (OHCA) outcomes using the smartphone-first-responder-system (SFRS) "Mobile Retter." METHODS: All adult non-traumatic OHCA in the district of Gütersloh between 01.01.2018-31.12.2021 were included. Periods of interest were 1) prior to the first COVID-19-lockdown; to 2) both lockdowns; and 3) the time in between, as well as after the COVID-19-lockdowns (pre-COVID-19, COVID-19-lockdown and COVID-19-pandemic respectively). The primary outcome was the CFR response rate defined as proportion of CFR alerts that were accepted by a CFR and in which at least one CFR arrived on scene of the emergency out of all CFR alerts. Secondary outcomes included the rate of CFR alerts, defined as proportion of OHCA to which CFR were summoned by the emergency medical dispatcher, as well as the rate of return-of-spontaneous-circulation (ROSC) and rate of survival until hospital discharge. We also examined the incidence COVID-19-infection of CFR in context of the SFRS. RESULTS: A total of 1064 OHCA-patients (mean age: 71.4±14.5 years; female: 33.8%) were included in the study (Pre-COVID-19: 539; COVID-19-lockdown: 109; COVID-19-pandemic: 416). The response rate was 64.0% (pre-COVID-19: 58.7%; COVID-19-lockdown: 63.5%; COVID-19-pandemic: 71.8%, P=0.002 vs. pre-COVID-19). The alert rate was 52.7% (pre-COVID-19: 56.2%; COVID-19-lockdown: 47.7%, P=0.04 vs. Pre-COVID-19; COVID-19-Pandemic: 49.5%, P=0.02 vs. pre-COVID-19). The ROSC-rate was 40.4% (pre-COVID-19: 41.0%; COVID-19-lockdown: 33.9%; COVID-19-pandemic: 41.4%) and hospital discharge rate 31.2% (Pre-COVID-19: 33.0%; COVID-19-lockdown: 36.8%; COVID-19-pandemic: 28.7%). The use of CFR was associated with favorable effects in terms of hospital admission (odds ratio [OR]: 0.654 (CI95: 0.444-0.963), P=0.03), hospital discharge (OR: 2.343 (CI95: 1.002-5.475), P=0.04). None of the CFR became infected with COVID-19. CONCLUSIONS: "Mobile-Retter" was associated with high response rates, improved outcome in OHCA patients and no COVID-19-infections of CFR during the COVID-19-pandemic and -lockdowns.

A parametric additive hazard model for time-to-event analysis.

BACKGROUND: In recent years, the use of non- and semi-parametric models which estimate hazard ratios for analysing time-to-event outcomes is continuously criticized in terms of interpretation, technical implementation, and flexibility. Hazard ratios in particular are critically discussed for their misleading interpretation as relative risks and their non-collapsibility. Additive hazard models do not have these drawbacks but are rarely used because they assume a non- or semi-parametric additive hazard which renders computation and interpretation complicated. METHODS: As a remedy, we propose a new parametric additive hazard model that allows results to be reported on the original time rather than on the hazard scale. Being an essentially parametric model, survival, hazard and probability density functions are directly available. Parameter estimation is straightforward by maximizing the log-likelihood function. RESULTS: Applying the model to different parametric distributions in a simulation study and in an exemplary application using data from a study investigating medical care to lung cancer patients, we show that the approach works well in practice. CONCLUSIONS: Our proposed parametric additive hazard model can serve as a powerful tool to analyze time-to-event outcomes due to its simple interpretation, flexibility and facilitated parameter estimation.

Association of plasma proteomics with incident coronary heart disease in individuals with and without type 2 diabetes: results from the population-based KORA study.

BACKGROUND: Coronary heart disease (CHD) is a major global health concern, especially among individuals with type 2 diabetes (T2D). Given the crucial role of proteins in various biological processes, this study aimed to elucidate the aetiological role and predictive performance of protein biomarkers on incident CHD in individuals with and without T2D. METHODS: The discovery cohort included 1492 participants from the Cooperative Health Research in the Region of Augsburg (KORA) S4 study with 147 incident CHD cases (45 vs. 102 cases in the group with T2D and without T2D, respectively) during 15.6 years of follow-up. The validation cohort included 888 participants from the KORA-Age1 study with 70 incident CHD cases (19 vs. 51 cases in the group with T2D and without T2D, respectively) during 6.9 years of follow-up. We measured 233 plasma proteins related to cardiovascular disease and inflammation using proximity extension assay technology. Associations of proteins with incident CHD were assessed using Cox regression and Mendelian randomization (MR) analysis. Predictive models were developed using priority-Lasso and were evaluated on top of Framingham risk score variables using the C-index, category-free net reclassification index (cfNRI), and relative integrated discrimination improvement (IDI). RESULTS: We identified two proteins associated with incident CHD in individuals with and 29 in those without baseline T2D, respectively. Six of these proteins are novel candidates for incident CHD. MR suggested a potential causal role for hepatocyte growth factor in CHD development. The developed four-protein-enriched model for individuals with baseline T2D (ΔC-index: 0.017; cfNRI: 0.253; IDI: 0.051) and the 12-protein-enriched model for individuals without baseline T2D (ΔC-index: 0.054; cfNRI: 0.462; IDI: 0.024) consistently improved CHD prediction in the discovery cohort, while in the validation cohort, significant improvements were only observed for selected performance measures (with T2D: cfNRI: 0.633; without T2D: ΔC-index: 0.038; cfNRI: 0.465). CONCLUSIONS: This study identified novel protein biomarkers associated with incident CHD in individuals with and without T2D and reaffirmed previously reported protein candidates. These findings enhance our understanding of CHD pathophysiology and provide potential targets for prevention and treatment.

Estimation of mortality rate ratios for chronic conditions with misclassification of disease status at death.

Estimation of mortality rates and mortality rate ratios (MRR) of diseased and non-diseased individuals is a core metric of disease impact used in chronic disease epidemiology. Estimation of mortality rates is often conducted through retrospective linkage of information from nationwide surveys such as the National Health Interview Survey (NHIS) and death registries. These surveys usually collect information on disease status during only one study visit. This infrequency leads to missing disease information (with right censored survival times) for deceased individuals who were disease-free at study participation, and a possibly biased estimation of the MRR because of possible undetected disease onset after study participation. This occurrence is called "misclassification of disease status at death (MicDaD)" and it is a potentially common source of bias in epidemiologic studies. In this study, we conducted a simulation analysis with a high and a low incidence setting to assess the extent of MicDaD-bias in the estimated mortality. For the simulated populations, MRR for diseased and non-diseased individuals with and without MicDaD were calculated and compared. Magnitude of MicDaD-bias depends on and is driven by the incidence of the chronic disease under consideration; our analysis revealed a noticeable shift towards underestimation for high incidences when MicDaD is present. Impact of MicDaD was smaller for lower incidence (but associated with greater uncertainty in the estimation of MRR in general). Further research can consider the amount of missing information and potential influencers such as duration and risk factors of the disease.