Survival analysis is composed of a group of analytical approaches that can be used to predict the occurrence of harvest activities,which provides insightful information about the dynamics of natural resources utilizat...Survival analysis is composed of a group of analytical approaches that can be used to predict the occurrence of harvest activities,which provides insightful information about the dynamics of natural resources utilization in a region.Recently,random survival forest(RSF)has been proposed in survival analysis to capture the complex relationships among variables.The main objective of this study was to employ the RSF algorithm to examine the temporal evolution of tree harvest,accounting for stand and environmental variables.Specifically,the predictability of the RSF model was compared with the Cox proportional hazard(Cox)model,a popular model in survival analysis.Important variables in explaining the variation of harvest time were identified.Data collected by the USDA Forest Service,Forest Inventory and Analysis(FIA)program from permanent plots in the southern Appalachian region were utilized in the analysis.Results showed that the RSF model consistently outperformed the Cox model based on prediction accuracy.Among 14 variables examined,ownership,forest type,elevation,state,and slope emerged as most important.Utilizing only these five variables in a reduced model produced satisfactory prediction accuracy compared to the full model(i.e.,the models with all variables included).The findings of this work provide insights for forest managers and policy makers to utilize survival analysis methods in understanding harvest activities at the regional scale.展开更多
Background Frailty is a new prognostic factor in cardiovascular medicine due to the aging and increasingly complex nature of elderly patients. It is useful and meaningful to prospectively analyze the manner in which f...Background Frailty is a new prognostic factor in cardiovascular medicine due to the aging and increasingly complex nature of elderly patients. It is useful and meaningful to prospectively analyze the manner in which frailty predicts short-term outcomes for elderly patients with acute coronary syndrome （ACS）. Methods Patients aged 〉 65 years, with diagnosis of ACS from cardiology department and geriatrics department were included from single-center. Clinical data including geriatrics syndromes were collected using Comprehensive Geriatrics Assessment. Frailty was defined according to the Clinical Frailty Scale and the impact of the co-morbidities on risk was quantified by the coronary artery disease （CAD）--specific index. Patients were followed up by clinical visit or telephone consultation and the median follow-up time is 120 days. Following-up items included all-cause mortality, unscheduled return visit, in-hospital and recurrent major adverse cardiovascular events. Multivariable regression survival analysis was performed using Cox regression. Results Of the 352 patients, 152 （43.18%） were considered frail according to the study instrument （5-7 on the scale）, and 93 （26.42%） were considered moderately or se- verely frail （6-7 on the scale）. Geriatrics syndromes including incontinence, fall history, visual impairment, hearing impairment, constipation, chronic pain, sleeping disorder, dental problems, anxiety or depression, and delirium were more frequently in frail patients than in non-frail patients （P = 0.000, 0.031, 0.009, 0.014, 0.000, 0.003, 0.022, 0.000, 0.074, and 0.432, respectively）. Adjusted for sex, age, severity of coro- nary artery diseases （left main coronary artery lesion or not） and co-morbidities （CAD specific index） by Cox survival analysis, frailty was found to be strongly and independently associated with risk for the primary composite outcomes： all-canse mortality [Hazard Ratio （HR） = 5.393; 95% CI： 1.477-19.692, P = 0.011] and unscheduled return visit （HR - 2.832; 95% CI： 1.140-7.037, P = 0.025）. Conclusions Comprehensive Geriatrics Assessment and Clinical Frail Scale were useful in evaluation of elderly patients with ACS. Frailty was strongly and independently associated with short-term outcomes for elderly patients with ACS.展开更多
BackgroundGeriatric patients with multivessel coronary artery disease （CAD） are a challenging group to treat; these cases elicit dis-cussion within heart teams regarding the actual benefit of undertaking major surge...BackgroundGeriatric patients with multivessel coronary artery disease （CAD） are a challenging group to treat; these cases elicit dis-cussion within heart teams regarding the actual benefit of undertaking major surgery on these patients and often lead to abandon the surgical option. Percutaneous procedures represent an important option, but coronary anatomy may be unfavorable. Off-pump coronary artery bypass （OPCAB） provides good quality graft on left anterior descending （LAD） without exposing the patient to cardiopulmonary bypass, and might be the ideal choice in patients with multiple comorbidities, not eligible to percutaneous or on-pump procedures. The objective of this study was to compare survival during a mid-term follow-up in high-risk patients with no percutaneous alternative, either treated with OPCAB or discharged in medical therapy.MethodsWe retrospectively evaluated from June 2008 to June 2013, 83 high-risk patients with multivessel CAD were included： 42 were treated with incomplete off-pump revascularization using left internal mammary artery （LIMA） on LAD; 41 were discharged in optimal medical therapy （OMT）, having refused surgery. Follow-up ended in March 2015, with a telephonic interview. Primary endpoint was survival from all-cause mortality; secondary endpoints were survival from cardiac-related mortality and freedom from non-fatal major adverse cardiac events （MACEs）.ResultsDuring follow up, 11 deaths in OPCAB group and 27 deaths in OMT group occurred. Death was due to cardiac factors in 6 and 15 patients, respectively. MACEs were observed in 6 patients in OPCAB group and in 4 patients in OMT group. With regards to survival from all-cause mortality, patients who underwent OPCAB survived more than those dis-charged in OMT （Log Rank ＆lt; 0.001）, and OMT group carries a propensity score-adjusted hazard ratio of 3.862 （P ＆lt; 0.001）. With regards to survival from cardiac-related events, patients who underwent OPCAB survived more than those discharged in OMT （Log Rank = 0.002）, and OMT group carries a propensity score-adjusted hazard ratio of 3.663 （P = 0.010）. There is no statistically significant difference concerning freedom from MACEs （Log Rank = 0.273）.ConclusionsFor high-risk patients with multivessel CAD, not eligible to on-pump complete revascularization surgery or percutaneous procedures, incomplete revascularization with OPCAB LIMA-on-LAD offers benefits in survival when compared to OMT alone.展开更多
基金Support from the USDA Forest Service(projects#21CR11330145063 and 21CR11330145069)The Nature Conservancy(project#030122-1)is greatly appreciated.
文摘Survival analysis is composed of a group of analytical approaches that can be used to predict the occurrence of harvest activities,which provides insightful information about the dynamics of natural resources utilization in a region.Recently,random survival forest(RSF)has been proposed in survival analysis to capture the complex relationships among variables.The main objective of this study was to employ the RSF algorithm to examine the temporal evolution of tree harvest,accounting for stand and environmental variables.Specifically,the predictability of the RSF model was compared with the Cox proportional hazard(Cox)model,a popular model in survival analysis.Important variables in explaining the variation of harvest time were identified.Data collected by the USDA Forest Service,Forest Inventory and Analysis(FIA)program from permanent plots in the southern Appalachian region were utilized in the analysis.Results showed that the RSF model consistently outperformed the Cox model based on prediction accuracy.Among 14 variables examined,ownership,forest type,elevation,state,and slope emerged as most important.Utilizing only these five variables in a reduced model produced satisfactory prediction accuracy compared to the full model(i.e.,the models with all variables included).The findings of this work provide insights for forest managers and policy makers to utilize survival analysis methods in understanding harvest activities at the regional scale.
文摘Background Frailty is a new prognostic factor in cardiovascular medicine due to the aging and increasingly complex nature of elderly patients. It is useful and meaningful to prospectively analyze the manner in which frailty predicts short-term outcomes for elderly patients with acute coronary syndrome （ACS）. Methods Patients aged 〉 65 years, with diagnosis of ACS from cardiology department and geriatrics department were included from single-center. Clinical data including geriatrics syndromes were collected using Comprehensive Geriatrics Assessment. Frailty was defined according to the Clinical Frailty Scale and the impact of the co-morbidities on risk was quantified by the coronary artery disease （CAD）--specific index. Patients were followed up by clinical visit or telephone consultation and the median follow-up time is 120 days. Following-up items included all-cause mortality, unscheduled return visit, in-hospital and recurrent major adverse cardiovascular events. Multivariable regression survival analysis was performed using Cox regression. Results Of the 352 patients, 152 （43.18%） were considered frail according to the study instrument （5-7 on the scale）, and 93 （26.42%） were considered moderately or se- verely frail （6-7 on the scale）. Geriatrics syndromes including incontinence, fall history, visual impairment, hearing impairment, constipation, chronic pain, sleeping disorder, dental problems, anxiety or depression, and delirium were more frequently in frail patients than in non-frail patients （P = 0.000, 0.031, 0.009, 0.014, 0.000, 0.003, 0.022, 0.000, 0.074, and 0.432, respectively）. Adjusted for sex, age, severity of coro- nary artery diseases （left main coronary artery lesion or not） and co-morbidities （CAD specific index） by Cox survival analysis, frailty was found to be strongly and independently associated with risk for the primary composite outcomes： all-canse mortality [Hazard Ratio （HR） = 5.393; 95% CI： 1.477-19.692, P = 0.011] and unscheduled return visit （HR - 2.832; 95% CI： 1.140-7.037, P = 0.025）. Conclusions Comprehensive Geriatrics Assessment and Clinical Frail Scale were useful in evaluation of elderly patients with ACS. Frailty was strongly and independently associated with short-term outcomes for elderly patients with ACS.
文摘BackgroundGeriatric patients with multivessel coronary artery disease （CAD） are a challenging group to treat; these cases elicit dis-cussion within heart teams regarding the actual benefit of undertaking major surgery on these patients and often lead to abandon the surgical option. Percutaneous procedures represent an important option, but coronary anatomy may be unfavorable. Off-pump coronary artery bypass （OPCAB） provides good quality graft on left anterior descending （LAD） without exposing the patient to cardiopulmonary bypass, and might be the ideal choice in patients with multiple comorbidities, not eligible to percutaneous or on-pump procedures. The objective of this study was to compare survival during a mid-term follow-up in high-risk patients with no percutaneous alternative, either treated with OPCAB or discharged in medical therapy.MethodsWe retrospectively evaluated from June 2008 to June 2013, 83 high-risk patients with multivessel CAD were included： 42 were treated with incomplete off-pump revascularization using left internal mammary artery （LIMA） on LAD; 41 were discharged in optimal medical therapy （OMT）, having refused surgery. Follow-up ended in March 2015, with a telephonic interview. Primary endpoint was survival from all-cause mortality; secondary endpoints were survival from cardiac-related mortality and freedom from non-fatal major adverse cardiac events （MACEs）.ResultsDuring follow up, 11 deaths in OPCAB group and 27 deaths in OMT group occurred. Death was due to cardiac factors in 6 and 15 patients, respectively. MACEs were observed in 6 patients in OPCAB group and in 4 patients in OMT group. With regards to survival from all-cause mortality, patients who underwent OPCAB survived more than those dis-charged in OMT （Log Rank ＆lt; 0.001）, and OMT group carries a propensity score-adjusted hazard ratio of 3.862 （P ＆lt; 0.001）. With regards to survival from cardiac-related events, patients who underwent OPCAB survived more than those discharged in OMT （Log Rank = 0.002）, and OMT group carries a propensity score-adjusted hazard ratio of 3.663 （P = 0.010）. There is no statistically significant difference concerning freedom from MACEs （Log Rank = 0.273）.ConclusionsFor high-risk patients with multivessel CAD, not eligible to on-pump complete revascularization surgery or percutaneous procedures, incomplete revascularization with OPCAB LIMA-on-LAD offers benefits in survival when compared to OMT alone.
