Adjusting for outcome misclassification: the importance of accounting for case-control sampling and other forms of outcome-related selection

PurposeSpecial care must be taken when adjusting for outcome misclassification in case-control data. Basic adjustment formulas using either sensitivity and specificity or predictive values (as with external validation data) do not account for the fact that controls are sampled from a much larger pool of potential controls. A parallel problem arises in surveys and cohort studies in which participation or loss is outcome related.MethodsWe review this problem and provide simple methods to adjust for outcome misclassification in case-control studies, and illustrate the methods in a case-control birth certificate study of cleft lip/palate and maternal cigarette smoking during pregnancy.ResultsAdjustment formulas for outcome misclassification that ignore case-control sampling can yield severely biased results. In the data we examined, the magnitude of error caused by not accounting for sampling is small when population sensitivity and specificity are high, but increases as (1) population sensitivity decreases, (2) population specificity decreases, and (3) the magnitude of the differentiality increases. Failing to account for case-control sampling can result in an odds ratio adjusted for outcome misclassification that is either too high or too low.ConclusionsOne needs to account for outcome-related selection (such as case-control sampling) when adjusting for outcome misclassification using external information.     

Metabolomics comparison of metabolites and functional pathways in the gills of Chlamys farreri under cadmium exposure

The biological processes of Chlamys farreri (C. farreri), an economically important shellfish, are affected when exposed to Cd²⁺. In this study, changes to biological processes and metabolite levels in C. farreri were examined when exposed to Cd²⁺. Ultra-performance liquid chromatography-tandem TOF mass spectrometry (UPLC-TOF/MS)-based untargeted metabolomics was used to examine changes in the metabolism of C. farreri gill tissue exposed to 0.050 mg/L Cd²⁺ for 96 h in a natural environment. Sixty-eight metabolites with significant differences were screened by multivariate statistical analysis. Eleven enriched functional pathways displayed significant changes in inactivity. Differential metabolites, mainly C00157 and C00350, have a significant impact on functional pathways and can be used as potential major biomarkers. Lipid phosphorylation, disruption of signal transduction, and autophagy activation were observed to change in C. farreri when exposed to Cd. The metabolome information supplements research on C. farreri exposure to heavy metals and provides a platform for further multi-omics analysis.     

我国城市地区癌症筛查项目人员对筛查工作意愿倾向的多中心调查及政策建议

目的 基于癌症筛查实际供方角度,从工作人员主观感受及意愿层面评价癌症筛查项目的可持续性。方法 2014-2015年,基于城市癌症早诊早治项目,在16个省份项目点选取2013-2015年所有承担项目的医院、CDC和社区卫生服务中心,采用纸质问卷和网络调查开展访谈,对象包括宏观管理人员、具体项目管理人员和一线工作人员等。结果 最终完成访谈4 626份,访谈对象总体认为参加项目的最大收获在于社会价值感的提升（63.6%）、当地影响力（35.9%）及专业技能提升（30.6%）等;最大困难在于社会物质激励不够所致工作积极性低（30.9%）、信息采集口径不一致（28.3%）、部门间协调（24.4%）和机构间沟通衔接困难（23.5%）等。当单项筛查服务劳务补偿约50元时,工作人员会考虑加班工作。63.7%的受访者有长期筛查服务意愿,主要原因：可通过项目提升个人/团队在当地影响口碑（48.7%）、通过项目提升个人/团队专业技能（43.1%）等;无服务意愿者主要担心工作量超负荷（59.8%）、对日常工作的干扰（49.8%）等。结论 收获与困难相关结果提示,若要长期可持续性开展癌症筛查工作,建议加强项目内荣誉激励、对外宣传及专业能力建设,根据具体情况提高劳务补偿。服务意愿结果则提示,应从政府和领导层面加强信息化建设及机构/部门间协调,机构内应合理协调筛查项目与日常工作。     

Using preference learning for detecting inconsistencies in clinical practice guidelines: Methods and application to antibiotherapy

Clinical practice guidelines provide evidence-based recommendations. However, many problems are reported, such as contradictions and inconsistencies. For example, guidelines recommend sulfamethoxazole/trimethoprim in child sinusitis, but they also state that there is a high bacteria resistance in this context. In this paper, we propose a method for the semi-automatic detection of inconsistencies in guidelines using preference learning, and we apply this method to antibiotherapy in primary care. The preference model was learned from the recommendations and from a knowledge base describing the domain.We successfully built a generic model suitable for all infectious diseases and patient profiles. This model includes both preferences and necessary features. It allowed the detection of 106 candidate inconsistencies which were analyzed by a medical expert. 55 inconsistencies were validated. We showed that therapeutic strategies of guidelines in antibiotherapy can be formalized by a preference model. In conclusion, we proposed an original approach, based on preferences, for modeling clinical guidelines. This model could be used in future clinical decision support systems for helping physicians to prescribe antibiotics.     

National,regional, and global trends in adult overweight and obesity prevalences

Background

Overweight and obesity prevalence are commonly used for public and policy communication of the extent of the obesity epidemic, yet comparable estimates of trends in overweight and obesity prevalence by country are not available.

Methods

We estimated trends between 1980 and 2008 in overweight and obesity prevalence and their uncertainty for adults 20 years of age and older in 199 countries and territories. Data were from a previous study, which used a Bayesian hierarchical model to estimate mean body mass index (BMI) based on published and unpublished health examination surveys and epidemiologic studies. Here, we used the estimated mean BMIs in a regression model to predict overweight and obesity prevalence by age, country, year, and sex. The uncertainty of the estimates included both those of the Bayesian hierarchical model and the uncertainty due to cross-walking from mean BMI to overweight and obesity prevalence.

Results

The global age-standardized prevalence of obesity nearly doubled from 6.4% (95% uncertainty interval 5.7-7.2%) in 1980 to 12.0% (11.5-12.5%) in 2008. Half of this rise occurred in the 20 years between 1980 and 2000, and half occurred in the 8 years between 2000 and 2008. The age-standardized prevalence of overweight increased from 24.6% (22.7-26.7%) to 34.4% (33.2-35.5%) during the same 28-year period. In 2008, female obesity prevalence ranged from 1.4% (0.7-2.2%) in Bangladesh and 1.5% (0.9-2.4%) in Madagascar to 70.4% (61.9-78.9%) in Tonga and 74.8% (66.7-82.1%) in Nauru. Male obesity was below 1% in Bangladesh, Democratic Republic of the Congo, and Ethiopia, and was highest in Cook Islands (60.1%, 52.6-67.6%) and Nauru (67.9%, 60.5-75.0%).

Conclusions

Globally, the prevalence of overweight and obesity has increased since 1980, and the increase has accelerated. Although obesity increased in most countries, levels and trends varied substantially. These data on trends in overweight and obesity may be used to set targets for obesity prevalence as requested at the United Nations high-level meeting on Prevention and Control of NCDs.

     

Electronic Medical Records and Electronic Health Records: Overview for Nurse Practitioners

Electronic medical records (EMRs) and electronic health records (EHRs) have become essential systems by which nurse practitioners (NPs) communicate vital patient information to other members of the health care team as well as to patients. In this article we examine the important distinctions between EMRs and EHRs; review the genesis of these types of records; summarize applicable provisions of the Health Insurance Portability and Accountability Act from a recent legal case centered around NP utilization of EMRs and EHRs; address open patient access to medical information; and examine threats to security. Suggestions are offered on ways in which NPs can safeguard confidential patient information.