Análisis del Impacto de la Temperatura en la Evaluación de Desempeño en un Programa de Ensayos de Aptitud

PACAL, as a provider of proficiency testing, evaluates the performance of participating clinical laboratories month by month using the variance index score. The samples sent for evaluation are assigned certain characteristics that could influence participants’ performance. This study aimed to determine whether the transport temperature of lyophilized clinical chemistry samples has any impact on performance evaluation by affecting the Variance Index Score (VIS) obtained by laboratories participating in the Quality Assurance Program (PACAL). Cycles 2404 to 2409 were analyzed, classifying the samples into two groups according to the reception temperature: between 2°C and 8°C, and above 8°C. The Kolmogorov-Smirnov test indicated that the data did not follow a normal distribution; therefore, the non-parametric Mann-Whitney U test was used to compare both groups. In all cases, no statistically significant differences were found (p > 0.05), indicating that the reception temperature does not affect VIS results. It is concluded that the use of lyophilized samples ensures analytical stability, even in the face of thermal variations during transport, guaranteeing the validity of external quality control in clinical chemistry.