Quantile regression and empirical likelihood for the analysis of longitudinal data with monotone missing responses due to dropout,with applications to quality of life measurements from clinical trials

The analysis of quality of life (QoL) data can be challenging due to the skewness of responses and the presence of missing data. In this paper, we propose a new weighted quantile regression method for estimating the conditional quantiles of QoL data with responses missing at random. The proposed method makes use of the correlation information within the same subject from an auxiliary mean regression model to enhance the estimation efficiency and takes into account of missing data mechanism. The asymptotic properties of the proposed estimator have been studied and simulations are also conducted to evaluate the performance of the proposed estimator. The proposed method has also been applied to the analysis of the QoL data from a clinical trial on early breast cancer, which motivated this study.     

Cost-effectiveness of breast cancer screening programme for women in rural China

In low and middle-income countries mammographic breast cancer screening is prohibitively expensive and a cheaper alternative option is to use ultrasound as the primary screening test. In 2009, China launched a breast cancer screening programme for rural women aged 35–64 years with clinical breast examination coupled with ultrasound as the primary tool. Our study aimed to analyse the cost-effectiveness of breast screening compared to no screening among Chinese rural women. We developed a Markov model to estimate the lifetime costs and effects for rural women aged 35 years from a societal perspective. Asymptomatic women in the intervention arm were screened every 3 years before age 64 years. Breast cancer in the non-screening arm can only be diagnosed on presentation of symptoms. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. Compared to no screening, breast cancer screening cost $186.7 more and led to a loss of 0.20 quality-adjusted life years (QALYs). Breast screening was more expensive and did harm to health among rural women with an incremental cost-effectiveness ratio (ICER) of $-916/QALY. The sensitivity analysis identified utility loss from false positives as the factor that most influenced the results, but this did not affect the conclusions. In a rural setting with such low breast cancer incidence, screening for asymptomatic disease is not cost-effective with current screening tools. Priority should be given to ensure that symptomatic women have proper access to diagnosis and treatment at an early stage as this will lead to mortality reductions without the usual screening harms.     

TRIM Proteins in Inflammation: from Expression to Emerging Regulatory Mechanisms

Inflammation - Inflammation is an immune response to exogenous or endogenous insults that helps to maintain the tissue homeostasis under stressful conditions. Depending on the differential types of...     

Day-level associations of physical activity and sedentary time in mother–child dyads across three years: a multi-wave longitudinal study using accelerometers

Journal of Behavioral Medicine - Understanding associations between mothers’ and children’s physical activity and sedentary behavior on more fine-grained timescales can provide insights...     

F形空心钉与传统3枚平行钉治疗Pauwels Ⅲ型股骨颈骨折的疗效比较

目的:分析比较"F"形空心钉与传统倒三角3枚平行螺钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折的临床疗效。方法：2017年1月至2020年1月收治Pauwels Ⅲ型股骨颈骨折患者38例，根据置入钉方式的不同将其分为两组，其中A组18例，采用"F"形空心钉固定，男12例，女6例，年龄37~55岁，受伤至手术时间1~3 d。B组20例，采用传统倒三角3枚平行拉力螺钉固定，男12例，女8例，年龄35~55岁，受伤至手术时间为1~3 d。比较两组患者骨折不愈合，股骨头坏死，股骨颈短缩，空心螺钉退出情况，髋关节功能Harris评分，疼痛视觉模拟评分（visual analogue scale，VAS）。结果：所有患者获得随访，时间为15~31个月。两组患者在骨折不愈合，股骨颈短缩，股骨头坏死方面差异无统计学意义（P>0.05）；两组患者在螺钉退出方面差异有统计学意义（P<0.05）。两组患者术后12个月时髋关节Harris评分及VAS评分差异均无统计学差异（P>0.05）。结论："F"形与传统倒三角3枚平行空心钉内固定治疗青壮年Pauwels Ⅲ型股骨颈骨折中短期疗效相似，但"F"形空心钉退钉率较低。