A computerized approach to statistical quality control for radioimmunoassays in the clinical chemistry laboratory

Methods for statistical quality control for the clinical laboratory in general, and radioimmunoassay in particular, have been proposed for many years. Unfortunately, only a very small number of laboratories have adapted these procedures. By use of teletypes and other remote terminals, it is possible for all laboratories to access centralized computers where a general purpose quality control program can be stored. This relieves each laboratory of the costly task of developing software, provides some degree of inter-laboratory standardization and facilitates comparison of precision and accuracy between laboratories. A prototype program for this purpose is described. This program evaluates within-assay and between-assay variability, by means of an analysis of variance for a one-way classification random-effects model, and can monitor any assay parameter by use of control chart techniques. In addition, several tests are provided to evaluate the temporal stability of the assay system, and appropriate tests for outliers are included. Also, methods are described for combination of information from several quality control samples. This provides a valid basis for adjustment of assay results or for outright rejection of an assay. For convenience, this program is designed for output on a teletype or similar terminal located in the laboratory. Simplified versions of this program can be readily adapted to desk-top calculators. The original purpose for developing this system was to provide the clinical laboratory with a simple, general, and flexible method for assessing the performance of radioimmunoassays, but its usefulness should extend to virtually all assay methods.     

Computer-assisted quality control in clinical chemistry

A MUMPS comuter program, which stores and retrieves quality-control data from all automated and manual work-station in the laboratory, has been developed as part of a laboratory information system. Tabular displays, Levey-Jennings charts, and summary statistics are available on a real-time basis. Significant economy over previous manual methods has been observed, and the total quality-control program in the laboratory has become a more active and timely process.     

均值-极差质量控制图在实验室检测质量控制中的应用

介绍了均值-极差质量控制图在实验室检测控制中的应用。通过绘制直读光谱仪测定20#钢材中碳含量的质量控制图,从图中找出潜在的对检测结果有影响的因素,并加以限制,从而有效预防质量检测事故的发生,是一种“预防为主”的检测质量控制管理手段。     

How to manage quality assurance at laboratories? A specialist''s examination is necessary in the specialty of clinical chemistry

Two thousand plus (2,000+) assisted laser surgical procedures were performed between July 1986 and November 1993. Multiwavelength specialties: Argon, CO2 and NdYAG usage include: general surgery, thoracic surgery, neurosurgery, ophthalmology, and gynecology. 65% of the patients were female whose ages range from 6 to 105 years. Endoscopic vs. handheld procedures ratios 1:1. In 95% of the cases attended, the procedures were performed for benign conditions. The office hospital usage distribution was 60-40%. The office morbidity was 0.8% (16 out of 2,000 cases) and a mortality of 0.15% (3 out of 2,000 cases). A reported 100% safety compliance was seen. Laser assisted surgery is a safe, effective and reliable option available to the surgeon's armamentarium. It appears that in some procedures it will allow shorter hospital stays and an earlier return of the patient to his/her normal routine.     

Multivariate changes in coordination of postural control following spaceflight

BACKGROUND: Bright light therapy is the recommended treatment for winter seasonal affective disorder (SAD). However, the studies with the best placebo controls have not been able to demonstrate that light treatment has a benefit beyond its placebo effect. METHODS: Ninety-six patients with SAD completed the study. Patients were randomly assigned to 1 of 3 treatments for 4 weeks, each 1.5 hours per day: morning light (average start time about 6 AM), evening light (average start about 9 PM), or morning placebo (average start about 6 AM). The bright light (approximately 6000 lux) was produced by light boxes, and the placebos were sham negative-ion generators. Depression ratings using the Structured Interview Guide for the Hamilton Depression Rating Scale, SAD version (SIGH-SAD) were performed weekly. RESULTS: There were no differences among the 3 groups in expectation ratings or mean depression scores after 4 weeks of treatment. However, strict response criteria revealed statistically significant differences; after 3 weeks of treatment morning light produced more of the complete or almost complete remissions than placebo. By 1 criterion (24-item SIGH-SAD score <50% of baseline and < or =8), 61% of the patients responded to morning light, 50% to evening light, and 32% to placebo after 4 weeks of treatment. CONCLUSIONS: Bright light therapy had a specific antidepressant effect beyond its placebo effect, but it took at least 3 weeks for a significant effect to develop. The benefit of light over placebo was in producing more of the full remissions.     

"Ocean-to-Ocean Project": a transcontinental external quality assessment trial in clinical chemistry realized throughout Eurasia

More than 800 diagnostic laboratories situated throughout the Eur-Asian continent--from the Pacific Coast up to the North Sea littoral--were involved in a common survey of External Quality Assessment (EQA). It consisted of the simultaneous measurement of up to 30 analytes of 'general' clinical chemistry using the same batch of control material. The laboratories were associated in four EQA institutions: SKZL (The Netherlands), OQUASTA (Austria), SEKK (Czech Republic) and BKKSystem (Community of Independent States). The results demonstrated the feasibility of such a large-scale survey and provided a realistic idea about the state-of-the-art of laboratory diagnosis in these countries: Besides some local specific problems, such as poor quality of water or the forced use of reagents and calibrators from different sources, there are general problems hindering an efficient process of 'harmonization' in laboratory medicine, namely, the high methodological dispersion especially in the case of enzymes and of some organic analytes. At the same time there is a potential necessity for more concentrated implementation of internal quality assessment into the routine work of laboratories.     

建立完善的质量控制系统,提高工程项目质量

介绍了质量控制系统的目标、要求、依据及如何建立一个完善的质量控制系统，达到提高工程项目质量的目的。     

Results and consequences of frequent quality control of quantitative clinical 1H-MR-spectroscopy

BACKGROUND: The cut-off point of serum C-reactive protein to differentiate the mild from the severe form of acute pancreatitis is still debated; data concerning the C-reactive protein pattern in assessing the severity of acute biliary pancreatitis are lacking. AIM: To define the best cut-off point in differentiating the severe from the mild form of acute biliary pancreatitis. PATIENTS: Fifty patients with acute biliary pancreatitis: 34 patients with mild pancreatitis and 16 with the severe form of the disease were studied. METHODS: Serum C-reactive protein concentrations were assessed in all patients upon admission and for the following 5 days. RESULTS: No significant difference in serum C-reactive protein levels was found in the first 2 days in patients with mild pancreatitis compared to those with the severe form of the disease. Using a cut-off point of 11 mg/dl, the sensitivity of serum C-reactive protein in assessing the severity of acute pancreatitis during the first two days of the study was 9% and 57%, the specificity, 93% and 81%, and the accuracy 71% and 74%, respectively. CONCLUSIONS: Serum determination of C-reactive protein in the first 48 hours of the disease is not a reliable marker of the severity of acute biliary pancreatitis.     

A laboratory-based approach to biological control of snails

Development of Schistosoma mansoni in the intermediate host Biomphalaria glabrata is influenced by a number of parasite and snail genes. Understanding the genetics involved in this complex host/ parasite relationship may lead to an often discussed approach of introducing resistant B. glabrata into the field as a means of biological control for the parasite. For the snail, juvenile susceptibility to the parasite is controlled by at least four genes, whereas one gene seems to be responsible for adult nonsusceptibility. Obtaining DNA from F2 progeny snails from crosses between parasite-resistant and -susceptible snails, we have searched for molecular markers that show linkage to either the resistant or susceptible phenotype. Both restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) approaches have been used. To date, using a variety of snail and heterologous species probes, no RFLP marker has been found that segregates with either the resistant or susceptible phenotype in F2 progeny snails. More promising results however have been found with the RAPD approach, where a 1.3 kb marker appears in nearly all resistant progeny, and a 1.1 kb marker appears in all susceptible progeny.     

Multimodal approach to control postoperative pathophysiology and rehabilitation

Major surgery is still associated with undesirable sequelae such as pain, cardiopulmonary, infective and thromboembolic complications, cerebral dysfunction, nausea and gastrointestinal paralysis, fatigue and prolonged convalescence. The key pathogenic factor in postoperative morbidity, excluding failures of surgical and anaesthetic technique, is the surgical stress response with subsequent increased demands on organ function. These changes in organ function are thought to be mediated by trauma-induced endocrine metabolic changes and activation of several biological cascade systems (cytokines, complement, arachidonic acid metabolites, nitric oxide, free oxygen radicals, etc). To understand postoperative morbidity it is therefore necessary to understand the pathophysiological role of the various components of the surgical stress response and to determine if modification of such responses may improve surgical outcome. While no single technique or drug regimen has been shown to eliminate postoperative morbidity and mortality, multimodal interventions may lead to a major reduction in the undesirable sequelae of surgical injury with improved recovery and reduction in postoperative morbidity and overall costs.     

An investment appraisal approach to clinical trial design

In this paper, a general investment appraisal model is presented which shows how pharmaceutical companies could take profit considerations into account when making decisions about the design of randomized controlled trials. A general model is presented based on the net present value method of investment appraisal. The approach is illustrated with a hypothetical example which shows how optimal (net present value maximizing) designs can be determined based on choices about sample size and endpoint measurement. The method could be extended to accommodate considerations about other trial design features, and could be used to determine a portfolio of studies which maximizes the expected return on a given development or trial budget. Furthermore, the approach could be used by pharmaceutical companies to evaluate the incremental costs and benefits of incorporating non-clinical objectives into trials, such as quality of life research and economic evaluation studies. A number of practical difficulties would need to be overcome to utilize the approach. Directions for further research are therefore highlighted centred on the key components of the model: a trial cost function, a product demand function, innovation diffusion processes and Bayesian approaches to trial design.     

Tutorial software for clinical chemistry incorporating interactive multimedia clinical cases

We have developed computer-based clinical case histories incorporating multimedia elements to aid the learning of medicine in a problem-based manner. Topics have been developed in the specialty of Clinical Biochemistry but the approach used is suitable for any branch of clinical medicine. Each topic has material aimed at medical students and also postgraduate candidates for professional examinations. A browser program is also incorporated. Emphasis is made on interaction through the case and modeling of real-life decisions in diagnosis and treatment. Advantages of the program are self-paced learning, assessment of understanding, feedback, and emphasis on deep understanding of the basic physiological and biochemical processes underlying clinical problems.