Two‐stage estimation of limited dependent variable models with errors‐in‐variables

Summary This paper deals with censored or truncated regression models where the explanatory variables are measured with additive errors. We propose a two‐stage estimation procedure that combines the instrumental variable method and the minimum distance estimation. This approach produces consistent and asymptotically normally distributed estimators for model parameters. When the predictor and instrumental variables are normally distributed, we also propose a maximum likelihood based estimator and a two‐stage moment estimator. Simulation studies show that all proposed estimators perform satisfactorily for relatively small samples and relatively high degree of censoring. In addition, the maximum likelihood based estimators are fairly robust against non‐normal and /or heteroskedastic random errors in our simulations. The method can be generalized to panel data models.     

Governance of preanalytical variability: Travelling the right path to the bright side of the moon?

Medical errors can be traditionally clustered into 4 categories, which include errors of diagnosis, errors of treatment, errors of prevention, and an ‘other miscellaneous’ category. Owing to the volume and complexity of testing, and considering that laboratory error is defined as any defect from ordering tests to reporting results and appropriately interpreting and reacting on these, it is not surprising that mistakes in the total testing process occur with frequency, have connections to all four types of medical errors and represent a serious hazard for patient health. Throughout the laboratory diagnostics, preanalytical problems prevail. Moreover, the positive trends towards reduction of laboratory errors over the past decade, particularly those in the analytical phase, has little involved the preanalytical phase, which actually represents the most critical area to target. In particular, the high frequency of errors still attributable to processes external to the laboratory requires additional efforts for the governance of this mistreated phase of the total testing process, so that we can finally find the right path to progress from the dark to the bright side of the moon. As for any other type of medical errors, the most effective path to improvement is the implementation of a total quality management system, encompassing a multifaceted strategy for process and risk analysis, based on error prevention, detection, and management.     

Locating the Seventh Cervical Spinous Process: Development and Validation of a Multivariate Model Using Palpation and Personal Information

Objective

The aim of this study was to develop and validate a multivariate prediction model, guided by palpation and personal information, for locating the seventh cervical spinous process (C7SP).

特殊部位异位妊娠的误诊原因分析及防范方法

目的:探讨特殊部位异位妊娠的临床特点、误诊原因及防范方法,以降低误诊率。方法:对我院2003-01~2007-04间106例特殊部位异位妊娠进行回顾性分析。结果:特殊部位异位妊娠占同期异位妊娠的4.48%,误诊率63.21%。误诊的主要原因有:临床症状不典型、病史询问及体检欠仔细、对特殊部位异位妊娠的临床表现认识不足、忽视绝育术后或放环者异位妊娠的可能性、辅助检查的错误提示。结论:应提高对特殊部位异位妊娠的警惕性及认识,以早期诊断和治疗,降低误诊率及死亡率。     

Evaluation of parenteral nutritional support in the surgical and medical wards of a referral teaching hospital

Background and purpose

Malnutrition is a common problem in patients who are hospitalized in surgical and medical wards. Surgical patients, geriatric populations and individuals with severe illness are more vulnerable to malnutrition during their hospitalization course.The purpose of this study was evaluation of parenteral nutrition services in a referral teaching hospital, Tehran, Iran.

Method

Medical records of 72 patients who received parenteral nutrition during one year period in different surgical and medical wards of Imam Khomeini hospital were reviewed retrospectively by clinical pharmacists. Criteria for initiation of parenteral nutrition, selection of appropriate formulation and monitoring parameters were assessed based on the American Society of Parenteral and Enteral Nutrition recommendations.

Results

Based on the patients'' anthropometric parameters and serum albumin levels, 4.2%, 75% and 20.8% of the patients were well-nourished, moderately malnourished and severely malnourished respectively at the hospital admission and before nutritional support. Adequate calorie, protein, carbohydrate and lipid supports were achieved in 21.1%, 32.4%, 23.7% and 10.5% of the patients respectively. About 91% of the patients experienced at least one complication of the nutritional support.

Conclusion

In this evaluation, several errors in assessment, establishing goals, and monitoring of parenteral nutrition regimens have been detected. Approximately all of the patients did not receive to the trace elements supports goals.     

Dissociation of Pe and ERN/Ne in the conscious recognition of an error

We evaluated the relationship between conscious awareness and the ERN/Ne and Pe in a digit entering task. On each trial, participants rated the accuracy of their responses on a three-point scale (incorrect, unsure, correct). The ERN/Ne was present on incorrect trials judged as incorrect. The Pe was evident on the same trials but also on correct and incorrect trials judged as unsure. We propose that the ERN/Ne occurs when there is an incorrect execution of a correct motor plan and the representation of the correct response is available for comparison with the actual response. The mismatch information that results from this comparison can be transferred to the Pe process and conscious awareness. However, the Pe process and conscious awareness do not only depend on this transfer of information from the ERN/Ne process. The Pe also occurs when there is uncertainty about the correctness of the motor plan, whether or not the plan is, in fact, correct.     

Gray matter morphology and the level of functioning in one-year follow-up of first-episode schizophrenia patients

Schizophrenia is a condition with a highly variable course that is hard to predict. The aim of the present study was to investigate if local gray matter volume (GMV) can differentiate poor (PF) and good (GF) functioning patients using voxel-wise analysis in a group of first-episode schizophrenia subjects (FES).     

克罗恩病52例临床诊断分析

背景:克罗恩病(CD)是一种全胃肠道节段性全壁层炎症性病变,其病因不明,临床表现多样,病理改变无特异性,误诊率高.目的:通过分析住院CD患者的临床资料,以期提高CD的早期诊断水平.方法:对仁济医院1993～2003年住院病例中52例出院诊断为CD患者的临床表现、诊断方法、确诊时间以及治疗和预后等进行总结和回顾分析.结果:腹痛(80.8%)、腹泻(57.7%)为本组住院CD患者最常见的胃肠道症状,消化道出血(44.2%)的发生率亦较高;病变常累及小肠(53.8%)和结肠(26.9%).结肠镜检查是末段回肠和结直肠病变最主要的诊断方法,其次为消化道钡剂检查,小肠病灶可通过小肠钡灌/胃肠钡餐或胶囊内镜、双气囊推进式小肠镜和磁共振小肠造影等检查方法发现.注意到微肉芽肿的特点可以提高活检组织非干酪性肉芽肿的检出率.52例CD入院时确诊40.4%,拟诊59.6%;2001年之后的误诊率和确诊时间与2000年之前相比没有下降.结论:CD临床表现多样且缺乏特异性,易延误诊断.结肠镜检查在CD的诊断中起关键作用,病变单独累及小肠时可采用小肠钡灌/胃肠钡餐或胶囊内镜、双气囊推进式小肠镜等检查方法以及早发现病灶.对拟诊患者应予相应治疗,考察疗效时对诊断进行再评估.     

嗜酸细胞性胃炎误诊1例

病例：患者男，34岁，医师。因中上腹痛反复发作2个月于2008年3月27日拟诊“胃占位”收入我院普外科。患者入院前2个月无明显诱因出现中上腹胀痛不适，疼痛无规律．夜间尤甚，无反射痛，伴有数次呕吐，呕吐为胃内容物，