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Tadashi Kawai

Publications and source records attributed to Tadashi Kawai.

17 recordsLinked to original sources
PubMed2006

[Validation of the ISO 15189 trial assessment results of clinical laboratories--effects of accreditation and interpretation of ISO 15189].

Japanese Committee for Clinical Laboratory Standards (JCCLS) and the Japan Accreditation Board for Conformity Assessment (JAB) have developed an accreditation program for clinical laboratories using ISO 15189 in Japan. On October 1, 2004, twelve clinical laboratories applied for trial accreditation assessment. Seven laboratories were selected, including a university hospital laboratory, two other hospital-based laboratories, three large private clinical laboratories and an other private clinical laboratory. JAB had given a one week-training course to the candidate technical assessors who were nominated from the Japanese Society of Laboratory Medicine (JSLM) and the Japanese Association of Medical Technologists (JAMT), and candidate system assessors who were nominated from JAB. Thirty-five members had successfully passed the examination. During the period from November 2004 to May 2005, five laboratories were visited for assessment by four to six assessors for two or three days. Final assessment reports were discussed by the program developing committee for the validation of the accreditation program. The conclusions were that the program did not have any critical problems, but the assessment visit would have been more efficient if JAB published an easily understandable guidance document on ISO 15189, and had some training courses for laboratories in Japan in order to understand ISO 15189 more deeply. In addition, JAB should develop a more simplified checklist, mainly describing the important requirements. JAB formally started the clinical laboratory accreditation scheme from August 1, 2005 and five laboratories were accredited by the newly started accreditation committee on August 31, 2005, and four laboratories were additionally accredited on November 28, 2005. The most difficult clauses in ISO 15189:2003 were 5.6.2 and 5.6.3 on uncertainty and traceability, and 5.7.1 on post-examination procedures. Some difficult clauses to understand in the International Standard were discussed.

Accreditation↗
PubMed2005

An iterative method for improved estimation of the mean of peer-group distributions in proficiency testing.

In proficiency testing (PT), the peer-group mean is conventionally computed after twice removing values exceeding the mean +/- 3 SD. However, this adjustment fails if there are many outliers. In this study an iterative method was evaluated as a more robust way to estimate the means. The methodology repeatedly removes a proportion of the population (usually those exceeding the mean +/- 1.6 SD), assuming the presence of a Gaussian distribution in the central portion, and reinflates the SD to compensate for the trimming. A computer simulation revealed that the estimated mean of a known Gaussian distribution was less affected by a subpopulation that overlaps the main population than was the conventional method. When the overlapping portions were removed, the iterative method predicted the true mean correctly. The method was applied to external PT results for 44 analytes. Although most peer-group distributions were clearly non-Gaussian, the segment included by the predicted mean +/- 1.6 SD was regarded as Gaussian in 85.9% by the new method and 73.4% by the conventional method. The proposed methodology appears to be an improved way of estimating peer-group means.

Algorithms↗
PubMed2005

Impact of a common CV evaluation scheme on overall laboratory performance: 8-year experience of a large national proficiency testing program in Japan.

In proficiency testing (PT), it is difficult to set rational criteria for determining target values and allowable limits. In Japan, the largest national PT program has for the past 8 years used an evaluation scheme based on a "common coefficient of variation" (cCV) to overcome this difficulty. The cCV, the average within-method variation, is derived by one-way analysis of variance from data of peer groups after excluding those with large variations. A unit interval used for grading participants is obtained by multiplying the cCV by the peer-group mean which is computed using an iterative method featuring repeated removal of a large portion of the tails of the distribution and reinflation of the standard deviation (SD) to compensate for the trimming. The evaluation scheme gives a relatively better grade to those participants in peer groups with small CVs, compared to use of individual peer-group CVs. The scheme has expedited the transition to more reproducible methods, resulting in a notable overall improvement in laboratory performance. The cCV evaluation scheme is uniformly applicable to any analyte measured quantitatively. The iterative method, an integral part of the scheme, effectively precludes bias in the evaluation.

Amylases↗
PubMed2005

[Current situation of the external quality control survey provided by the Japan Medical Association and its problems].

The Japan Medical Association (JMA) has been providing the external quality survey program in clinical laboratory testing for the past 37 years, 2,812 labs participated in 2003, and it has improved overall interlaboratory variations, particularly in enzyme activity examinations. There are many other external quality survey programs provided independently by the other organizations, and the JMA Committee on Quality Control Survey in Clinical Laboratory Testing, in association with JCCLS and the other expert panels, had discussed on the possibility of implementing a new external quality assessment scheme, named NEQAS (National External Quality Assessment Scheme). The current problems on the external quality control survey are discussed.

Clinical Laboratory Techniques↗
PubMed2005

[Age- and sex-specific reference intervals for 10 health examination items: mega-data from a Japanese Health Service Association].

OBJECTIVE: To determine age- and sex-specific reference intervals for 10 health examination items in Japanese adults. METHODS: Health examination data were accumulated from 24 different prefectural health service associations affiliated with the Japan Association of Health Service. Those who were non-smokers, drank less than 7 days/week, and had a body mass index of 18.5-24.9kg/m2 were sampled as a reference population (n = 737,538; 224,947 men and 512,591 women). After classified by age and sex, reference intervals for 10 health examination items (systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, glucose, uric acid, AST, ALT, gamma-GT, and hemoglobin) were estimated using the parametric and nonparametric methods. RESULTS: In every item except for hemoglobin, men had higher reference intervals than women. Systolic blood pressure, total cholesterol, and glucose showed an upward trend in values with increasing age. Hemoglobin showed a downward trend in values with increasing age. Triglyceride, ALT, and gamma-GT reached a peak in middle age. Overall, parametric estimates showed narrower reference intervals than non-parametric estimates. CONCLUSION: Reference intervals vary with age and sex. Age- and sex-specific reference intervals may contribute to better assessment of health examination data.

Adult↗
PubMed2004

[Accreditation of clinical laboratories based on ISO standards].

International Organization for Standardization (ISO) have published two international standards (IS) to be used for accreditation of clinical laboratories; ISO/IEC 17025:1999 and ISO 15189:2003. Any laboratory accreditation body must satisfy the requirements stated in ISO/IEC Guide 58. In order to maintain the quality of the laboratory accreditation bodies worldwide, the International Laboratory Accreditation Cooperation (ILAC) has established the mutual recognition arrangement (MRA). In Japan, the International Accreditation Japan (IAJapan) and the Japan Accreditation Board for Conformity Assessment (JAB) are the members of the ILAC/MRA group. In 2003, the Japanese Committee for Clinical Laboratory Standards (JCCLS) and the JAB have established the Development Committee of Clinical Laboratory Accreditation Program (CLAP), in order to establish the CLAP, probably starting in 2005.

Accreditation↗
PubMed2003

[A perspective toward EBD/EBLM].

Evidence-based diagnosis(EBD) or evidence-based laboratory medicine(EBLM) is indispensable for supporting evidence-based medicine. EBLM consists of 4 steps; systematic reviewing of published literatures, planning of and reporting on adequate utilization of laboratory testing in primary studies, development of useful practice guidelines and implementation of these guidelines into daily medical practice. There should be many approaches to accomplish patient-oriented adequate utilization of laboratory tests through continuing efforts by both individual laboratory scientists and scientific societies.

Clinical Laboratory Techniques↗
PubMed2002

[Postgraduate education of AP/CP in USA and its introduction into Japan].

The pathology residency training in 1960s in USA was described through the author's experience in University of Miami School of Medicine and Jackson Memorial Hospital. After the author passed the American Board of Pathology examinations in both Anatomic Pathology(AP) and Clinical Pathology(CP) successfully, the author returned back to Japan, and tried to introduce the residency training program. However, the Japanese Society of Pathology and the Japanese Society of Laboratory Medicine(formerly, Japan Society of Clinical Pathology) have established independently their certification systems for pathologists and laboratory physicians.

Anatomy↗