The compliance score as a regressor in randomized trials

The compliance score in randomized trials is a measure of the effect of randomization on treatment received. It is in principle a group-level pretreatment variable and so can be used where individual-level measures of treatment received can produce misleading inferences. The interpretation of models with the compliance score as a regressor of interest depends on the link function. Using the identity link can lead to valid inference about the effects of treatment received even in the presence of nonrandom noncompliance; such inference is more problematic for nonlinear links. We illustrate these points with data from two randomized trials.     

Monitoring surgical performance using risk-adjusted cumulative sum charts

The cumulative sum (CUSUM) procedure is a graphical method that is widely used for quality monitoring in industrial settings. More recently it has been used to monitor surgical outcomes whereby it 'signals' if sufficient evidence has accumulated that there has been a change in the surgical failure rate. A limitation of the standard CUSUM procedure in this context is that since it is simply based on the observed surgical outcomes, it may signal as a result of changes in the referral pattern, such as an increased proportion of high-risk patients, rather than due to a change in the actual surgical performance. We describe a new CUSUM procedure that adjusts for each patient's pre-operative risk of surgical failure through the use of a likelihood-based scoring method. The procedure is therefore ideally suited for settings where there is a variable mix of patients over time.     

The Use of Multiple Outcomes Analysis in Neurotoxicity: An Example from the New Zealand Study of Offspring of Mothers Exposed to Methyl Mercury

Neurotoxicity has become an important area in the study of the risk to children of noncarcinogens. Many of the tests used to evaluate neurotoxic effects in neurotoxic studies are psychometric tests to assess cognitive, motor, and perceptual performance in individuals in order to determine the presence of psychological problems, impaired educational achievement, or neurological abnormalities. The underlying assumption of these procedures are that a test performance deficit is indicative of a neurological disability, and that such disability derives from the prenatal exposure to an offending substance. The usual analytic paradigm for discerning environmental impacts is to analyze the scores of a particular subtest in a battery taken separately as the dependent variable with regression analysis, which adjusts for cultural background, educational level, and socioeconomic status. The impact of this analysis is to determine the correlation of each of the psychometric test results to exposure. We show a statistical method to simultaneously analyze the multiple outcomes of many tests using General Estimating Equations (GEE) to determine if a correlation exists between the global measure of all these tests and exposure adjusted for covariates of interest and the correlation among the dependent psychometric variables. We show the application of this method to the results of children whose mothers were exposed to mercury during pregnancy.     

孕妇孕期营养指导及体质量控制对妊娠结局的影响

目的:对孕妇进行孕期营养指导及体质量控制,探究其对妊娠结局的影响。方法:将2011年2月-2014年2月期间我院收治的孕产妇150例纳入本次研究,所有研究对象随机均衡分为研究组和对照组,每组各75例。对照组孕产妇仅行常规妇科检查,研究组孕产妇在医护人员指导下行孕期营养指导和体质量控制,比较两组分娩方式,妊娠过程状况及围产儿情况。结果:研究组剖宫产率为17.33%低于对照组的57.33%,组间差异存在统计学意义(P0.05)。研究组贫血、羊水过少、产后出血率均低于对照组,差异有统计学意义(P0.05)。研究组胎龄及巨大儿及胎儿窘迫率均低于对照组,差异有统计学意义(P0.05)。结论:孕产妇在孕期进行营养膳食指导,控制体质量在合理范围内,可以改善孕妇妊娠结局,降低妊娠过程中并发症发病率,提高围产儿状况,保证孕妇和婴儿健康。     

女性甲状腺癌的病理与预后分析

目的:探讨女性甲状腺癌的病理特点以及预后影响因素。方法:收集2005年1月至2009年8月,齐齐哈尔和平医院收治的女性甲状腺癌患者148例,回顾分析其临床病理特点以及预后影响因素。结果:病理检查显示131例(88.5%)甲状腺乳头状癌(PTC),6例(4.1%)为滤泡状癌(FTC),3例(2.0%)为髓样癌(MTC),6例(4.1%)为未分化癌(ATC);病理分期Ⅰ-Ⅱ期占45.3%,Ⅲ-Ⅳ期占54.7%;27例(18.24%)为周围组织侵犯,9例(6.1%)为远处转移,10例(6.76%)对侧甲状腺转移,56例(37.84%)颈部淋巴结转移;1年、3年、5年生存率依次为97.3%、93.2%、83.8%;年龄、病理床分期、病理类型、淋巴结转移、远处转移以及周围组织侵犯均是影响临床预后的重要因素(P0.05)。结论:女性甲状腺癌存在病理分期晚、病理分型差、淋巴结转移、远处转移及局部侵犯率高等不良预后因素,早期影像学检查对临床治疗具有指导意义。     

The year of transparency: measuring quality of cardiac care

The assessment of quality of care is becoming increasingly important in healthcare, both globally and in the Netherlands. The Dutch Minister of Health declared 2015 to be the year of transparency, thereby aiming to improve quality of care by transparent reporting of outcome data. With the increasing importance of transparency, knowledge on quality measurement will be essential for a cardiologist in daily clinical care. To that end, this paper provides a comprehensive overview of the Dutch healthcare structure, quality indicators and the current and future assessment of quality of cardiac care in the Netherlands.     

Factors Affecting Revegetation of Oil Field Access Roads in Semiarid Grassland

We assessed vegetation recovery on access roads removed after well abandonment in an active oil‐producing region of northern Great Plains grasslands. We compared extant vegetation on 58 roads, restored 3–22 years previously, to records of species seeded on each and to adjacent, undisturbed prairie, to evaluate main differences between the restored and adjacent community and to explore patterns in the restored plant community over time. The restored plant community was dominated by low richness of seeded non‐native and native grasses and forbs, whereas adjacent prairie had numerous, abundant native graminoids and shrubs and higher richness of native forbs. Cover of seeded species on roads was double that of colonizing species. Disparity in cover of dominant native grasses between the adjacent community and relatively narrow restored roadway suggests that conditions for germination and survival in roadbeds are poor. This is at least partly due to persistence of seeded species. Differences in restored plant composition over time were best explained by changes in species seeded, from non‐natives to natives, and secondarily by successional shifts from ruderal to perennial non‐seeded species. Of the 30 species seeded at least once on these roads, only 10 were commonly used. The long‐term influence of seeding choices in grassland road restorations implies that improvements in these practices will be critical to reversing ecological impacts of roads.     

Phosphodiesterase inhibitor 3-isobutyl-methyl-xanthine stimulates reproduction in rabbit females

The aim of our study was to examine the influence of 3-isobutyl-1-methyl-xanthine (IBMX), an inhibitor of cyclic adenosine monophosphate and cyclic guanosine monophosphate phosphodiesterases, on the reproductive efficiency of gonadotropin-stimulated rabbits (Oryctolagus cuniculus, Leporidae, Lagomorpha). The ovarian cycle and ovulation of control rabbits was induced by pregnant mare serum gonadotropin (PMSG) followed by administration of human chorionic gonadotropin (hCG; first series of experiments) or gonadotropin-releasing hormone (GnRH; second series of experiments). Experimental animals received PMSG and hCG together with IBMX (at 5 or 25 μg/animal) or GnRH together with IBMX (at 50 or 500 μg/animal). After ovulation and mating, in the first series of experiments, animals were killed; the pronuclear-stage eggs were flushed from the oviducts and cultured up to blastocyst cell stage. Numbers of ovarian corpora lutea, ovulated oocytes, and oocyte-derived embryos reaching blastocyst stage were determined. In the second series of experiments, all the animals were kept until parturition, when the pregnancy and birth rate, litter size, and number, viability, and body weight of pups were recorded. IBMX injections at doses of 5 or 25 μg/animal significantly increased the number of ovulations/corpora lutea, harvested zygotes, and embryos derived from these zygotes. Administration of IBMX at doses of 500 μg/animal or 50 μg/animal to nulliparous young animals (4.5 mo of age) significantly increased their pregnancy rate and birth rate, litter size, and litter weight. In multiparous old animals (2 yr of age), IBMX at a dose of 50 μg/animal, but not 500 μg/animal, significantly increased their pregnancy rate and litter size, but not the birth rate, number of pups per female, or litter weight. These data demonstrate that (1) IBMX can enhance the stimulatory effect of GnRH/gonadotropins on rabbit ovulation, oocyte maturation, embryo yield and development, pregnancy and birth rate, and number, viability, and body weight of pups; (2) nulliparous young females (4.5 mo of age) are more sensitive to IBMX treatments than the multiparous old animals (2 yr of age); and (3) cyclic nucleotides-dependent intracellular mechanisms are involved in control of rabbit reproductive functions and IBMX, an activator of these mechanisms, can be a stimulator of reproduction and fertility.     

污染环境中具有生育脉冲的单种群模型的最优捕获问题

研究周期性脉冲毒素输入的污染环境中具有生育脉冲的单种群捕获模型的动力学性质,通过数值模拟给出所研究系统的动力复杂性,并进一步指出脉冲捕获的时间对最大年度持续产量的影响.