This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Fai...This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Failure Time (AFT) model, Cox Proportional Hazards model, and Survival model, we assess the effectiveness of these models in capturing survival rates across varying gender, age groups, and treatment categories. Simulated data was used to fit the models, with model identification criteria (AIC, BIC, and R2) applied for evaluation. Results indicate that the AFT model is particularly sensitive to interaction terms, showing significant effects for older age groups (50 - 60 years) and treatment interaction, while the Cox model provides a more stable fit across all age groups. The Survival model displayed variability, with its performance diminishing when interaction terms were introduced, particularly in older age groups. Overall, while the AFT model captures the complexities of interactions in the data, the Cox model’s stability suggests it may be better suited for general analyses without strong interaction effects. The findings highlight the importance of model selection in survival analysis, especially in complex disease progression scenarios like HIV/AIDS.展开更多
目的探讨基于Cox-IMCHB理论的健康行为互动模式对胆囊术后患者营养支持的影响。方法采用方便抽样法,选择2023年1-12月东莞市厚街医院普外科收治的胆囊术后住院患者100例为研究对象,其中1-6月就诊的胆囊术后患者50例为对照组,7-12月就诊...目的探讨基于Cox-IMCHB理论的健康行为互动模式对胆囊术后患者营养支持的影响。方法采用方便抽样法,选择2023年1-12月东莞市厚街医院普外科收治的胆囊术后住院患者100例为研究对象,其中1-6月就诊的胆囊术后患者50例为对照组,7-12月就诊的胆囊术后患者50例为干预组。对照组采用常规护理,干预组在常规护理基础上给予基于Cox-IMCHB理论的健康行为互动模式。比较两组患者营养指标、炎症指标、胃肠道症状评分(Gastrointestinal Symptom Score,GIS)、胃肠生活质量指数评分(Gastrointestinal quality of life index,GIQLI)。结果干预组患者术后1个月营养指标数值皆高于对照组(t=2.358、-4.904、-4.960,均P<0.05),炎症指标数值皆高于对照组(t值为3.931、2.064、8.324,均P<0.05),GIS评分低于对照组(t=3.219,P<0.05),GIQLI总分及各维度评分均高于对照组(t=-7.984、-3.559、-7.118、-2.726、-2.905,P<0.05)。结论基于Cox-IMCHB理论的健康行为互动模式可有效改善胆囊术后患者的营养状态,减缓其炎症情况,改善其胃肠道症状及其生活质量。展开更多
Classical survival analysis assumes all subjects will experience the event of interest, but in some cases, a portion of the population may never encounter the event. These survival methods further assume independent s...Classical survival analysis assumes all subjects will experience the event of interest, but in some cases, a portion of the population may never encounter the event. These survival methods further assume independent survival times, which is not valid for honey bees, which live in nests. The study introduces a semi-parametric marginal proportional hazards mixture cure (PHMC) model with exchangeable correlation structure, using generalized estimating equations for survival data analysis. The model was tested on clustered right-censored bees survival data with a cured fraction, where two bee species were subjected to different entomopathogens to test the effect of the entomopathogens on the survival of the bee species. The Expectation-Solution algorithm is used to estimate the parameters. The study notes a weak positive association between cure statuses (ρ1=0.0007) and survival times for uncured bees (ρ2=0.0890), emphasizing their importance. The odds of being uncured for A. mellifera is higher than the odds for species M. ferruginea. The bee species, A. mellifera are more susceptible to entomopathogens icipe 7, icipe 20, and icipe 69. The Cox-Snell residuals show that the proposed semiparametric PH model generally fits the data well as compared to model that assume independent correlation structure. Thus, the semi parametric marginal proportional hazards mixture cure is parsimonious model for correlated bees survival data.展开更多
文摘This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Failure Time (AFT) model, Cox Proportional Hazards model, and Survival model, we assess the effectiveness of these models in capturing survival rates across varying gender, age groups, and treatment categories. Simulated data was used to fit the models, with model identification criteria (AIC, BIC, and R2) applied for evaluation. Results indicate that the AFT model is particularly sensitive to interaction terms, showing significant effects for older age groups (50 - 60 years) and treatment interaction, while the Cox model provides a more stable fit across all age groups. The Survival model displayed variability, with its performance diminishing when interaction terms were introduced, particularly in older age groups. Overall, while the AFT model captures the complexities of interactions in the data, the Cox model’s stability suggests it may be better suited for general analyses without strong interaction effects. The findings highlight the importance of model selection in survival analysis, especially in complex disease progression scenarios like HIV/AIDS.
文摘目的探讨基于Cox-IMCHB理论的健康行为互动模式对胆囊术后患者营养支持的影响。方法采用方便抽样法,选择2023年1-12月东莞市厚街医院普外科收治的胆囊术后住院患者100例为研究对象,其中1-6月就诊的胆囊术后患者50例为对照组,7-12月就诊的胆囊术后患者50例为干预组。对照组采用常规护理,干预组在常规护理基础上给予基于Cox-IMCHB理论的健康行为互动模式。比较两组患者营养指标、炎症指标、胃肠道症状评分(Gastrointestinal Symptom Score,GIS)、胃肠生活质量指数评分(Gastrointestinal quality of life index,GIQLI)。结果干预组患者术后1个月营养指标数值皆高于对照组(t=2.358、-4.904、-4.960,均P<0.05),炎症指标数值皆高于对照组(t值为3.931、2.064、8.324,均P<0.05),GIS评分低于对照组(t=3.219,P<0.05),GIQLI总分及各维度评分均高于对照组(t=-7.984、-3.559、-7.118、-2.726、-2.905,P<0.05)。结论基于Cox-IMCHB理论的健康行为互动模式可有效改善胆囊术后患者的营养状态,减缓其炎症情况,改善其胃肠道症状及其生活质量。
文摘Classical survival analysis assumes all subjects will experience the event of interest, but in some cases, a portion of the population may never encounter the event. These survival methods further assume independent survival times, which is not valid for honey bees, which live in nests. The study introduces a semi-parametric marginal proportional hazards mixture cure (PHMC) model with exchangeable correlation structure, using generalized estimating equations for survival data analysis. The model was tested on clustered right-censored bees survival data with a cured fraction, where two bee species were subjected to different entomopathogens to test the effect of the entomopathogens on the survival of the bee species. The Expectation-Solution algorithm is used to estimate the parameters. The study notes a weak positive association between cure statuses (ρ1=0.0007) and survival times for uncured bees (ρ2=0.0890), emphasizing their importance. The odds of being uncured for A. mellifera is higher than the odds for species M. ferruginea. The bee species, A. mellifera are more susceptible to entomopathogens icipe 7, icipe 20, and icipe 69. The Cox-Snell residuals show that the proposed semiparametric PH model generally fits the data well as compared to model that assume independent correlation structure. Thus, the semi parametric marginal proportional hazards mixture cure is parsimonious model for correlated bees survival data.
