Acceptable variability in external quality assessment programmes for basic semen analysis.

BACKGROUND: External quality assessment is essential in modern andrology laboratories. To assess the proficiency of laboratories participating in an external quality assessment programme (EQAP), limits for acceptable variability must be determined. Limits currently specified largely depend on criteria set by the organizers of individual EQAP schemes. The objective of this study was to evaluate the different criteria described in ISO 13528: 2005 for calculating acceptable variability in EQAP when applied to basic semen analysis parameters. METHODS AND RESULTS: The data used in this study were the means and standard deviations obtained for independent samples from two EQAPs, one national (Spanish) and one international (European). The acceptable variability according to ISO 13528: 2005 was calculated using four types of criteria: (i) ± 3 standard deviations of the results of all participating laboratories; (ii) ± 3 standard deviations of the results of expert laboratories; (iii) quality specifications based on biological variability, state-of-the-art and clinicians' opinions and (iv) the same quality specifications adjusted for the uncertainty of the assigned value. The first two strategies resulted in very wide ranges of acceptable variability. Conversely, the strategy based only on quality specifications resulted in very narrow ranges. For the fourth strategy, acceptable ranges were intermediate between the results produced with the other strategies. The third and fourth strategies did not produce observable differences in acceptable ranges when the model used for calculating the specifications of analytical quality was changed. CONCLUSIONS: It is essential that EQAPs for semen parameters should determine the ranges for acceptable variability in results. Moreover, these ranges must be clinically useful, i.e. the variability should have a minimal negative impact on clinical decisions. The exact definition of 'expert laboratory' is more important than the model chosen for estimating analytical quality specifications in an EQAP for semen parameters in basic semen analysis.

Quality specifications for seminal parameters based on clinicians' opinions.

BACKGROUND: The aim of this study was to identify analytical quality specifications for seminal parameters based on clinicians' opinions, and to compare with those based on biological variability and state of the art. MATERIAL AND METHODS: Two questionnaires with case histories were sent to laboratories participating in the Spanish programme of external quality on semen analysis for distribution to as many specialist clinicians as possible. Our intention was to determine the critical difference (CD), defined as the difference needed between two consecutive results obtained from semen analysis to be 95 % confident that the two results actually are different. Subsequently, we calculated the specifications of analytical quality in accordance with the clinicians' opinions. RESULTS: The CDs obtained from the median value of the differences between the initial value and that given in the clinicians' replies were similar in clinical situations of improvement or worsening in the infertile normozoospermic male, and also in worsening situations for male patients presenting a significant alteration in seminal parameters. For improvement in this latter case, the CD cited as necessary in the clinicians' opinion was much higher than that for the other clinical situations. At a desirable level of quality, for concentration and total motility the coefficients of variation in the clinicians' opinion were below those based on biological variability and the state of the art. However, for type "a+b" motility, type "a" motility, morphology and vitality the coefficients of variation based on the clinicians' opinions were higher than those based on biological variability and lower than those based on the state of the art. CONCLUSIONS: Quality specifications for seminal parameters based on clinicians' opinions depend to a large extent on the clinical situation and on the seminal parameter being analysed.

Quality specifications for seminal parameters based on the state of the art.

BACKGROUND: The aim of this study was to calculate the analytical goal for seminal parameters based on the state of the art, and then to compare these specifications with those previously obtained by our group based on biological variation. METHODS: All data used for analysis were derived from the Spanish programme of external quality control on semen analysis. Over 90 laboratories participated from 1999 to 2003. Using graphs of the state of the art, we also determined the numbers of laboratories that achieved quality specifications. RESULTS: The total allowable error calculated using state of the art graphs is similar to that calculated using biological variation for concentration and total motility. However, it is much higher for morphology and rapidly progressive motility. Over 80% of the laboratories achieved the minimum quality specification based on biological variation for concentration, total and progressive motility. However, only approximately 30% of the laboratories achieved the minimum quality specification based on biological variation for morphology and rapidly progressive motility. CONCLUSIONS: The study enabled us to identify the state of the art of analytical performance for seminal parameters, and revealed the difficulty inherent in meeting the quality specifications based on biological variation.

Criterios AEFA sobre la Norma UNE-EN ISO 15189 / Criteria of AEFA on the Norm ISO 15189

La Norma 15189 ha significado un paso definitivo en el reconocimiento formal de la calidad en los laboratorios de análisis clínicos. La Asociación Española de Farmacéuticos Analistas entiende que es el documento de referencia obligada para cualquier tema relacionado con la calidad, ya que contiene requisitos aplicables al proceso analítico en su conjunto, así como a la gestión y a la competencia técnica del laboratorio. En el presente documento se presenta en una primera parte una introducción a la Norma y, en segundo lugar; los criterios que la Comisión de Certificación y Acreditación de AEFA tiene sobre diferentes aspectos de la misma, tanto en su aspecto formal como en sus requerimientos técnicos

The standard ISO 15189 has meant a definitive step in the formal recognition of the quality in the medical laboratories. AEFA understands that it is the document of referencet orced for any topic related to the quality, since it contains requeriments applicable to the analytical process in his ser, as well as to the management and to the technical competence of the medicallaboratory. In the present document one presents in the first part an introduction to the Norm and, secondly, the criteria that the Comisión de Certificación y Acreditación de AEFA has on different aspects ofthe same one, both in his formal aspect and in his technical requeriments