Background Relationships between in-hospital mortality and case volume were investigated for various patient groups in many empirical studies with mixed results. Typically, those studies relied on (semi-)parametric statistical models like logistic regression. Those models impose strong assumptions on the functional form of the relationship between outcome and case volume. The aim of this study was to determine associations between in-hospital mortality and hospital case volume using random forest as a flexible, nonparametric machine learning method. Methods We analyzed a sample of 753,895 hospital cases with stroke, myocardial infarction, ventilation > 24 h, COPD, pneumonia, and colorectal cancer undergoing colorectal resection treated in 233 German hospitals over the period 2016–2018. We derived partial dependence functions from random forest estimates capturing the relationship between the patient-specific probability of in-hospital death and hospital case volume for each of the six considered patient groups. Results Across all patient groups, the smallest hospital volumes were consistently related to the highest predicted probabilities of in-hospital death. We found strong relationships between in-hospital mortality and hospital case volume for hospitals treating a (very) small number of cases. Slightly higher case volumes were associated with substantially lower mortality. The estimated relationships between in-hospital mortality and case volume were nonlinear and nonmonotonic. Conclusion Our analysis revealed strong relationships between in-hospital mortality and hospital case volume in hospitals treating a small number of cases. The nonlinearity and nonmonotonicity of the estimated relationships indicate that studies applying conventional statistical approaches like logistic regression should consider these relationships adequately.

L'objectiu d'aquest treball era avaluar la mortalitat hospitalària de la cirurgia coronaria en malalts de la sanitat pública operats en centres de gestió pública i privada de Catalunya, mitjançant l'ús de dues escales de risc (l'EuroSCORE i un model d'àmbit local). S'analitzà també la validesa dels mètodes d'avaluació i es comparà el resultat de la cirurgia sense circulació extracorpòria respecte de la cirurgia amb circulació extracorpòria. Es van incloure tots els malalts consecutius (1.605) sotmesos a una primera intervenció d'empelt coronari aïllat durant dos anys en cinc hospitals. Els resultats indiquen que a Catalunya: 1) La gestió privada del centre s'associa marginalment amb una millor supervivència. 2) L'efectivitat de la cirurgia coronària a millorat en els últims anys. 3) Ambdós instruments d'ajust del risc son útils per a l'avaluació d'aquests resultats. 4) La cirurgia sense circulació extracorpòria s'associa a millors resultats, sobre tot en els pacients amb risc preoperatori baix. / El objetivo de este trabajo era evaluar la mortalidad hospitalaria de la cirugía coronaria de los pacientes de la sanidad pública operados en centros de gestión pública y privada de Cataluña, mediante dos escalas de riesgo (el EuroSCORE y una de ámbito local). Se analizó también la validez de los métodos de evaluación y se comparó el resultado de la cirugía sin circulación extracorporea con el de la cirugía con circulación extracorporea.Se incluyeron los pacientes (1.605) sometidos a una primera intervención de implante aortocoronario aislado durante dos años en cinco centros.Los resultados indican que en Cataluña: La gestión privada se asocia marginalmente a mejor supervivencia. La efectividad de la cirugía coronaria ha mejorado en los últimos años. Ambos instrumentos de ajuste del riesgo resultan útiles para la evaluación de estos resultados. La cirugía sin circulación extracorporea se asocia a mejores resultados, sobre todo en pacientes de riesgo bajo. / The objective of the present study was to evaluate hospital mortality after coronary surgery in patients from the public health system operated on in public and private centers, using two risk scores (the EuroSCORE and a locally derived model). In addition, validity of such evaluating methods was assessed and the results of off-pump and on-pump coronary surgery were compared.All consecutive patients (1.605) undergoing a first isolated coronary by-pass procedure during two years were recruited in five hospitals.The results show that in Catalonia: 1) Private hospital management is associated to a maginal increase in hospital survival. 2) Effectiveness of coronary by-pass surgery has increased compared to previous evaluations. 3) Both risk scores showed complementary properties fort he evaluation of results. 4) Off-pump coronary surgery is associated to better results and the association is grater in low risk patients.

Made available in DSpace on 2011-05-04T12:36:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2009 / OBJETIVO: Avaliar a efetividade do tratamento hospitalar do Acidente Vascular Cerebral Agudo no Sistema Único de Saúde SUS, comparando a mortalidade hospitalar ajustada entre pacientes que realizaram ou não a tomografia computadorizada. MÉTODO: A fonte de informação utilizada foi o Sistema de Informação Hospitalar do SUS (SIH-SUS). Foram selecionadas 328.087 internações ocorridas no SUS em todo o território nacional entre abril de 2006 e dezembro de 2007. As internações foram reunidas e estudadas em 4 grupos: Acidente Isquêmico Transitório (CID-10: G459); Acidente Vascular Cerebral Hemorrágico (CID-10: I60; I61 e I62); Acidente Vascular Isquêmico (CID-10: I63) e Acidente Vascular Cerebral não especificado (CID-10: I64). Foram utilizadas as mortalidades hospitalares até o sétimo e até o trigésimo dias, como medidas de resultado para comparar pacientes que realizaram e não realizaram tomografia computadorizada. RESULTADOS: Em geral os pacientes que realizaram a tomografia computadorizada apresentaram menores taxas de mortalidade hospitalar em relação àqueles que não realizaram o exame, sendo essa diferença em favor da realização do exame observada principalmente até o segundo dia de internação em todos os 4 grupos. A diferença entre os que realizaram e os que não realizaram o exame foi acentuada no grupo do Acidente Vascular Isquêmico (OR: 0,325; p>0,000), sendo que no primeiro dia o odds ratio foi de 0,021(p>0,000), em favor dos que realizaram o exame. CONCLUSÕES: Os exames de tomografia computadorizada no SUS, em geral, são realizados mais tardiamente que o recomendado pela literatura. Apesar das limitações ainda existentes na qualidade da informação diagnóstica disponível no SIH-SUS que restringiram a estratégia de ajuste de risco empregada nesse estudo, sugere-se o uso da tomografia computadorizada, o mais cedo possível, como tecnologia auxiliar no diagnóstico e tratamento do AVC. Além disso, sugere-se o emprego mais amplo de medidas de desempenho, tais como a mortalidade hospitalar aqui empregada, para o monitoramento da qualidade do cuidado prestado no âmbito do SUS. / OBJECTIVE: To evaluate the effectiveness of hospital care of the Stroke in the Brazilian Health System by comparing adjusted hospital mortality rate between patients who had done or not CT scanning. METHOD: Brazilian hospital information systems was the data source used. Three hundred twenty eight thousand and eighty seven inpatients were included in this study, covering all the Brazilian territory between April of 2006 and December of 2007. The inpatients had been grouped in 4 groups: Transient cerebral ischaemic attack, unspecified (ICD-10: G45.9); Haemorrhage Stroke (ICD -10: I60; I61 and I62); Cerebral infaction (ICD -10: I63) and Stroke not specified as haemorrhage or infarction (ICD -10: I64). Hospital mortality until seventh and the thirtieth day was used as a result measure to compare patients who had been submitted or not to Computerized tomography (CT) scanning. RESULTS: In general the patients who submitted to TC scanning presented lower hospital mortality rates in relation to those who had not done CT scanning, being this difference for the accomplishment of the examination observed until the second day of in-hospital all stroke group. The group of the ischemic stroke presented the higher difference among those who were submitted or not to Computerized tomography (CT) scanning (OR: 0.325; p>0.000). In the first in-hospital day for the stroke group the odds ratio 0.021 (p>0.000) in favor of the group who had done the CT. CONCLUSIONS: The TC scans in the Brazilian health system, in general, are used with a greater delay than the recommended in literature. This leads to a reduction of the benefits of the examination. Although the limitations in the data quality of Brazilian hospital, the use of the TC scanning, as soon as possible, is suggested as auxiliary technology in the diagnosis and treatment of the stroke. Furthermore, it is also suggested a more frequent employment of performance indicator, such as hospital mortality rate, to monitoring quality of care in Brazil.

No / Hospitals are under pressure to reduce waiting times and costs. One strategy that may be effective focuses on optimising the flow of emergency patients. We undertook a patient flow analysis of older emergency patients to identify and address delays in ensuring timely care, without additional resources. Prospective systems redesign study over 2 years. The Geriatric Medicine Directorate in an acute hospital (Sheffield Teaching Hospitals NHS Foundation Trust) with 1920 beds. Older patients admitted as emergencies. Diagnostic patient flow analysis followed by a series of Plan Do Study Act cycles to test and implement changes by a multidisciplinary team using time series run charts. 60% of patients aged 75+ years arrived in the Emergency Department during office hours, but two-thirds of the admissions to GM wards were outside office hours highlighting a major delay. Three changes were undertaken to address this, Discharge to Assess, Seven Day Working and the establishment of a Frailty Unit. Average bed occupancy fell by 20.4 beds (95% confidence interval (CI) -39.6 to -1.2, P = 0.037) for similar demand. The risk of hospital mortality also fell by 2.25% (before 11.4% (95% CI 10.4-12.4%), after 9.15% (95% CI 7.6-10.7%) which equates to a number needed to treat of 45 and a 19.7% reduction in relative risk of mortality. The risk of re-admission remained unchanged. Redesigning the system of care for older emergency patients led to reductions in bed occupancy and mortality without affecting re-admission rates or requiring additional resources.

Introdução: Estima-se que ocorram 2,5 milhões de mortes por ano relacionadas a cirurgias não cardíacas e cinco vezes este valor para morbidade, com limitações funcionais e redução na sobrevida em longo prazo. Pacientes que deverão ser submetidos à cirurgia vascular são considerados de risco aumentado para eventos adversos cardiovasculares no pós-operatório. Há, ainda, muitas dúvidas em como fazer uma avaliação pré-operatória mais acurada desses pacientes. Objetivo: Em pacientes submetidos à cirurgia vascular arterial eletiva, avaliar a incidência e preditores de complicações cardiovasculares e/ou óbito total, e calcular a performance dos modelos de estratificação de risco mais utilizados. Métodos: Em pacientes adultos, consecutivos, operados em hospital terciário, determinou-se a incidência de complicações cardiovasculares e óbitos, em 30 dias e em um ano. Comparações univariadas e regressão logística avaliaram os fatores de risco associados com os desfechos e a curva ROC (receiver operating characteristic) examinou a capacidade discriminatória do Índice de Risco Cardíaco Revisado (RCRI) e do Índice de Risco Cardíaco do Grupo de Cirurgia Vascular da New England (VSG-CRI). Resultados: Um total de 141 pacientes (idade média 66 anos, 65% homens) realizou cirurgia de: carótida 15 (10,6%), membros inferiores 65 (46,1%), aorta abdominal 56 (39,7%) e outras (3,5%). Complicações cardiovasculares e óbito ocorreram, respectivamente, em 28 (19,9%) e em 20 (14,2%), em até 30 dias, e em 20 (16,8%) e 10 (8,4%), de 30 dias a um ano. Complicações combinadas ocorreram em 39 (27,7%) pacientes em até 30 dias e em 21 (17,6%) de 30 dias a um ano da cirurgia. Para eventos em até 30 dias, os preditores de risco encontrados foram: idade, obesidade, acidente vascular cerebral, capacidade funcional ruim, cintilografia com hipocaptação transitória, cirurgia aberta, cirurgia de aorta e troponina alterada. Os escores Índice de Risco Cardíaco Revisado (RCRI) e Índice de Risco Cardíaco do Grupo de Estudo Vascular da New England (VSG-CRI) obtiveram AUC (area under curve) de 0,635 e 0,639 para complicações cardiovasculares precoces e 0,562 e 0,610 para óbito em 30 dias, respectivamente. Com base nas variáveis preditoras aqui encontradas, testou-se um novo escore pré-operatório que obteve AUC de 0,747, para complicações cardiovasculares precoces, e um escore intraoperatório que apresentou AUC de 0,840, para óbito em até 30 dias. Para eventos tardios (de 30 dias a 1 ano), os preditores encontrados foram: capacidade funcional ruim, pressão arterial sistólica, cintilografia com hipocaptação transitória, ASA (American Society of Anesthesiologists Physical Status) classe > II, RCRI (AUC 0,726) e troponina alterada. Conclusões: Nesse grupo pequeno e selecionado de pacientes de elevada complexidade clínica, submetidos à cirurgia vascular arterial, a incidência de eventos adversos foi elevada. Para complicações em até 30 dias, mostramos que os índices de avaliação de risco mais utilizados até o momento (RCRI e VSG-CRI) não apresentaram boa performance em nossa amostra. A capacidade preditiva de um escore mais amplo pré-operatório, e uma análise de risco em dois tempos: no pré-operatório e no pós-operatório imediato, como o que simulamos, poderá ser mais efetiva em estimar o risco de complicações / Introduction: Approximately 2.5 million deaths are caused by non-cardiac surgeries per year, while morbidity, represented by functional impairment and a decline in long-term survival, accounts for five times this value. Patients who require a vascular surgery are considered at an increased risk for adverse cardiovascular events in the postoperative period. However, the method for obtaining a more accurate preoperative evaluation in these patients has not yet been determined. Objective: In patients undergoing elective arterial vascular surgery, the incidence and predictors of cardiovascular complications and/or total death were determined and the performance of risk stratification models was assessed. Methods: The incidence of cardiovascular complications and death within 30 days and 1 year after vascular surgery was determined in consecutive adult patients operated in a tertiary hospital. Univariate comparison and logistic regression analysis were used to evaluate risk factors associated with the outcome, and the receiver operating characteristic (ROC) curve determined the discriminatory capacity of the Revised Cardiac Risk Index (RCRI) and the Cardiac Risk Index of the New England Vascular Surgery Group (VSG-CRI). Results: In all, 141 patients (mean age, 66 years; 65% men) underwent vascular surgery, namely for the carotid arteries (15 [10.6%]), inferior limbs (65 [46.1%]), abdominal aorta (56 [39.7%]), and others (5 [3.5%]). Cardiovascular complications and death occurred in 28 (19.9%) and 20 (14.2%) patients, respectively, within 30 days after surgery, and in 20 (16.8%) and 10 (8.4%) patients, respectively, between 30 days and 1 year after the surgical procedure. Combined complications occurred in 39 patients (27.7%) within 30 days and in 21 patients (17.6%) between 30 days and 1 year after surgery. The risk predictors for cardiovascular events that occurred within 30 days were age, obesity, stroke, poor functional capacity, transitory myocardial hypocaptation on scintigraphy, open surgery, aortic surgery, and abnormal troponin levels. The RCRI and VSG-CRI showed an under the curve area of 0.635 and 0.639 for early cardiovascular complications as well as of 0.562 and 0.610 for death within 30 days, respectively. Based on the predictors found in this study, a new preoperative score was proposed, based on an AUC of 0.747 obtained for early cardiovascular complications and an intraoperative score that presented an AUC of 0.840 for death within 30 days. For late events (between 30 days and 1 year), the predictors were poor functional capacity, systolic blood pressure, presence of transitory myocardial hypocaptation on scintigraphy, class > II American Society of Anesthesiologists Physical Status score, RCRI (AUC= 0.726), and abnormal troponin levels. Conclusions: In this small group of patients with increased clinical complexity who underwent arterial surgery, the incidence of adverse events was high. In our series, we found that RCRI and VSG-CRI do not reasonably predict the risk of cardiovascular complications. The predictive capacity of a modified preoperative score and evaluating the risk preoperatively and early postoperatively, such as that simulated in this study, may be more effective in determining the risk of complications

Introdução: Estima-se que ocorram 2,5 milhões de mortes por ano relacionadas a cirurgias não cardíacas e cinco vezes este valor para morbidade, com limitações funcionais e redução na sobrevida em longo prazo. Pacientes que deverão ser submetidos à cirurgia vascular são considerados de risco aumentado para eventos adversos cardiovasculares no pós-operatório. Há, ainda, muitas dúvidas em como fazer uma avaliação pré-operatória mais acurada desses pacientes. Objetivo: Em pacientes submetidos à cirurgia vascular arterial eletiva, avaliar a incidência e preditores de complicações cardiovasculares e/ou óbito total, e calcular a performance dos modelos de estratificação de risco mais utilizados. Métodos: Em pacientes adultos, consecutivos, operados em hospital terciário, determinou-se a incidência de complicações cardiovasculares e óbitos, em 30 dias e em um ano. Comparações univariadas e regressão logística avaliaram os fatores de risco associados com os desfechos e a curva ROC (receiver operating characteristic) examinou a capacidade discriminatória do Índice de Risco Cardíaco Revisado (RCRI) e do Índice de Risco Cardíaco do Grupo de Cirurgia Vascular da New England (VSG-CRI). Resultados: Um total de 141 pacientes (idade média 66 anos, 65% homens) realizou cirurgia de: carótida 15 (10,6%), membros inferiores 65 (46,1%), aorta abdominal 56 (39,7%) e outras (3,5%). Complicações cardiovasculares e óbito ocorreram, respectivamente, em 28 (19,9%) e em 20 (14,2%), em até 30 dias, e em 20 (16,8%) e 10 (8,4%), de 30 dias a um ano. Complicações combinadas ocorreram em 39 (27,7%) pacientes em até 30 dias e em 21 (17,6%) de 30 dias a um ano da cirurgia. Para eventos em até 30 dias, os preditores de risco encontrados foram: idade, obesidade, acidente vascular cerebral, capacidade funcional ruim, cintilografia com hipocaptação transitória, cirurgia aberta, cirurgia de aorta e troponina alterada. Os escores Índice de Risco Cardíaco Revisado (RCRI) e Índice de Risco Cardíaco do Grupo de Estudo Vascular da New England (VSG-CRI) obtiveram AUC (area under curve) de 0,635 e 0,639 para complicações cardiovasculares precoces e 0,562 e 0,610 para óbito em 30 dias, respectivamente. Com base nas variáveis preditoras aqui encontradas, testou-se um novo escore pré-operatório que obteve AUC de 0,747, para complicações cardiovasculares precoces, e um escore intraoperatório que apresentou AUC de 0,840, para óbito em até 30 dias. Para eventos tardios (de 30 dias a 1 ano), os preditores encontrados foram: capacidade funcional ruim, pressão arterial sistólica, cintilografia com hipocaptação transitória, ASA (American Society of Anesthesiologists Physical Status) classe > II, RCRI (AUC 0,726) e troponina alterada. Conclusões: Nesse grupo pequeno e selecionado de pacientes de elevada complexidade clínica, submetidos à cirurgia vascular arterial, a incidência de eventos adversos foi elevada. Para complicações em até 30 dias, mostramos que os índices de avaliação de risco mais utilizados até o momento (RCRI e VSG-CRI) não apresentaram boa performance em nossa amostra. A capacidade preditiva de um escore mais amplo pré-operatório, e uma análise de risco em dois tempos: no pré-operatório e no pós-operatório imediato, como o que simulamos, poderá ser mais efetiva em estimar o risco de complicações / Introduction: Approximately 2.5 million deaths are caused by non-cardiac surgeries per year, while morbidity, represented by functional impairment and a decline in long-term survival, accounts for five times this value. Patients who require a vascular surgery are considered at an increased risk for adverse cardiovascular events in the postoperative period. However, the method for obtaining a more accurate preoperative evaluation in these patients has not yet been determined. Objective: In patients undergoing elective arterial vascular surgery, the incidence and predictors of cardiovascular complications and/or total death were determined and the performance of risk stratification models was assessed. Methods: The incidence of cardiovascular complications and death within 30 days and 1 year after vascular surgery was determined in consecutive adult patients operated in a tertiary hospital. Univariate comparison and logistic regression analysis were used to evaluate risk factors associated with the outcome, and the receiver operating characteristic (ROC) curve determined the discriminatory capacity of the Revised Cardiac Risk Index (RCRI) and the Cardiac Risk Index of the New England Vascular Surgery Group (VSG-CRI). Results: In all, 141 patients (mean age, 66 years; 65% men) underwent vascular surgery, namely for the carotid arteries (15 [10.6%]), inferior limbs (65 [46.1%]), abdominal aorta (56 [39.7%]), and others (5 [3.5%]). Cardiovascular complications and death occurred in 28 (19.9%) and 20 (14.2%) patients, respectively, within 30 days after surgery, and in 20 (16.8%) and 10 (8.4%) patients, respectively, between 30 days and 1 year after the surgical procedure. Combined complications occurred in 39 patients (27.7%) within 30 days and in 21 patients (17.6%) between 30 days and 1 year after surgery. The risk predictors for cardiovascular events that occurred within 30 days were age, obesity, stroke, poor functional capacity, transitory myocardial hypocaptation on scintigraphy, open surgery, aortic surgery, and abnormal troponin levels. The RCRI and VSG-CRI showed an under the curve area of 0.635 and 0.639 for early cardiovascular complications as well as of 0.562 and 0.610 for death within 30 days, respectively. Based on the predictors found in this study, a new preoperative score was proposed, based on an AUC of 0.747 obtained for early cardiovascular complications and an intraoperative score that presented an AUC of 0.840 for death within 30 days. For late events (between 30 days and 1 year), the predictors were poor functional capacity, systolic blood pressure, presence of transitory myocardial hypocaptation on scintigraphy, class > II American Society of Anesthesiologists Physical Status score, RCRI (AUC= 0.726), and abnormal troponin levels. Conclusions: In this small group of patients with increased clinical complexity who underwent arterial surgery, the incidence of adverse events was high. In our series, we found that RCRI and VSG-CRI do not reasonably predict the risk of cardiovascular complications. The predictive capacity of a modified preoperative score and evaluating the risk preoperatively and early postoperatively, such as that simulated in this study, may be more effective in determining the risk of complications