Sampling‐based estimation for massive survival data with additive hazards model

For massive survival data, we propose a subsampling algorithm to efficiently approximate the estimates of regression parameters in the additive hazards model. We establish consistency and asymptotic normality of the subsample‐based estimator given the full data. The optimal subsampling probabilities are obtained via minimizing asymptotic variance of the resulting estimator. The subsample‐based procedure can largely reduce the computational cost compared with the full data method. In numerical simulations, our method has low bias and satisfactory coverage probabilities. We provide an illustrative example on the survival analysis of patients with lymphoma cancer from the Surveillance, Epidemiology, and End Results Program.     

Mendelian randomization analysis with survival outcomes

Mendelian randomization (MR) is an established approach for assessing the causal effects of heritable exposures on outcomes. Outcomes of interest often include binary clinical endpoints, but may also include censored survival times. We explore the implications of both the Cox proportional hazard model and the additive hazard model in the context of MR, with a specific emphasis on two‐stage methods. We show that naive application of standard MR approaches to censored survival times may induce significant bias. Through simulations and analysis of data from the Women's Health Initiative, we provide practical advice on modeling survival outcomes in MRs.     

Development of a composite indicator to prioritize districts for implementation of human immunodeficiency virus programmes in Maharashtra,India

A key recommendation of the National AIDS Control Programme‐IV of India was to develop new strategies for geo‐prioritization of the human immunodeficiency virus (HIV) epidemic. We conducted this study to categorize the districts in Maharashtra (India) based on a multidimensional framework for geo‐prioritization of services. Programmatic data on trends of HIV prevalence, coverage of marginalized populations and vulnerability factors were included. A composite indicator based on these was developed, and the cumulative score was calculated for each district. HIV prevalence among general population has declined steadily from 0.60% in 2007 to 0.33% in 2017. The programme coverage was stable but inadequate for men who have sex with men (MSM). The coverage for female sex workers (FSWs) was inadequate and reduced over time. Nine districts were categorized as high priority, 13 as moderate priority and 11 were classified as low‐priority districts based on burden and vulnerability for HIV. The high‐priority districts were Pune, Solapur and Yavatmal for FSW interventions and Pune, Thane and Latur for MSM interventions. This multidimensional indicator is based on existing programmatic data, dynamic and can be made state‐specific. It is useful to categorize and prioritize districts for allocation of resources and geo‐prioritization of services in resource limited settings.     

医疗服务价格调整对公立医院收入结构的影响研究——基于成分数据分析方法

目的基于三级甲等公立医院运营数据,分析医疗服务价格调整对医院收入结构的影响。方法引入成分数据分析方法,利用浙江省12家三级甲等公立医院(综合医院7家、中医类医院2家、专科医院3家) 2019年1—7月收入结构数据模拟无政策干预下8—12月数据,比较实际数据与模拟数据的差异。结果调价后综合医院、中医类医院和专科医院的医疗服务收入占比分别提高了4.77、4.01和2.54个百分点,检验和检查收入占比分别减少了0.60、0.78和2.94个百分点。综合性医院和中医类医院的药占比降低了1.87和5.29个百分点。各类医院服务收入增加了10 890.14万元,药品收入减少了6 521.79万元,检验检查收入减少了3 065.96万元。结论医疗服务价格调整政策提高了服务收入占比,降低了物耗性收入占比。下一步需建立医疗服务价格动态调整机制,继续控制医疗费用不合理增长,并关注不同类型医院收入结构的差异。     

基于成分等时替代模型的高中生身体活动与焦虑症状相关性分析

目的 了解高中生在居家网课期间身体活动、焦虑症状状况及其相关性,为高中生的身心健康干预提供科学依据。方法 2020年4月,某校高中生以问卷星形式完成在线调查,内容包括:一般资料、生活作息、身体活动、焦虑自评量表。采用成分等时替代模型分析高中生24 h行为活动（包括身体活动、静坐行为和睡眠）与焦虑症状的相关性。结果 共调查1 324人,高中生焦虑症状患病率为23.34%。10 min中高强度身体活动（MVPA）替代久坐行为（SB）、低强度身体活动（LPA）与焦虑得分减少相关有统计学意义（平均变化量分别为 - 0.25（95%CI: - 0.47～ - 0.04）、 - 0.24（95%CI : - 0.46～ - 0.02））。随着 MVPA 替代 LPA、SB和睡眠（SLP）的时间增加,焦虑得分预测值减少量增加。结论 高中生居家网课期间焦虑情绪不容忽视,进行中高强度身体活动能有效预防焦虑症状发生。     

粗糙集在构建骨肿瘤辅助诊断知识库的应用研究

在骨肿瘤辅助诊断专家系统研究中，知识库的建立是一直困扰系统建立的瓶颈问题，知识库的好坏不仅影响到后续推理过程，而且还对诊断的精度有着很大的影响。本文使用基于粗糙集理论的数据挖掘技术，对已确诊病例资料数据库进行数据分析，建立骨肿瘤与患者临床表现之间的推理关系，并结合医生的临床实践，最终形成一个比较完备的辅助诊断知识数据库，为后续的推理、解释程序打下良好的基础。     

一种心电数据压缩算法的研究

利用心电信号的相关性，对ECG进行预处理，再进行差值运算，将得到的差值序列进行DCT变换，从而实现心电数据的压缩。     

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (R f c value)

Summary This article reports TLC data (corrected R_f values; R _f ^c values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.     

朝鲜族人群鼻部肿瘤

[目的 ]了解朝鲜族的各种鼻部肿瘤的发病率并确定针对高发鼻部肿瘤的研究课题 .[方法 ]调查 1990年 1月到 1999年 10月之间在延边大学医学院附属医院病理科经活检确诊为鼻部肿瘤的全部患者的原始记录 .[结果 ]发现了 82例朝鲜族鼻部肿瘤患者 .其中 ,发病率最高的为乳头状瘤 ( 3 6/ 82 ) ,其次为鳞状上皮癌 ( 13 / 82 ) .[结论 ]朝鲜族鼻部乳头状瘤的发病率明显高于国内其它地区 .必须提高对鼻部乳头状瘤的诊断和治疗水平 ,并加快有关鼻部乳头状瘤和人类乳头状瘤病毒之间的关系的研究 .     

Effect of regular training on the anthropometric parameters and urine steroids in childhood

The changes in the anthropometric data and urine steroid metabolites caused by regular training in children in two age groups (11 and 14 years old) were investigated. The skinfolds of older girls participating in regular athletic, swimming or soccer training were thinner compared with age-matched control groups (P < 0.01) and their body mass and constitution were lower (P < 0.05). In the other groups no significant differences were observable in the anthropometric parameters. The trained children in all groups had significantly higher exercise times on the cycle ergometer (P < 0.01, in young boysP < 0.05). The strength of their hands was lower in three trained groups: in younger boys (P < 0.05), in younger girls (P < 0.01) and in older girls (right handP < 0.01, left handP < 0.05). The urinary excretion of androsterone (P < 0.02), 11-ketopregnanetriol (P < 0.01) and pregnenetriol (P < 0.02) was decreased in the older trained girls; pregnenetriol was increased in younger boys (P < 0.05). Urinary excretion of cortisol metabolites was increased in trained boys [in younger boys: tetrahydrocorticosterone (P < 0.05) and 20-hydroxycortisol (P < 0.05); in older boys allotetrahydrocortisol (P < 0.02), cortisol (P < 0.05) and 20-hydroxycortisol (P < 0.05)]. There were no significant differences in the younger girls. In the trained older girls urinary excretion of cortisol metabolites was decreased: tetrahydrocortisone (P < 0.02), allotetrahydrocorticosterone (P < 0.01), tetrahydrocortisol (P < 0.05), -cortolone (P < 0.01), cortisol (P < 0.02), 6-hydroxycortisol (P < 0.01) and 20-hydroxycortisol (P < 0.05). A multivariate analysis of the data from the trained groups and sedentary, age-matched control groups showed that regular training has a significant effect on steroid excretion.