External quality assessment / proficiency testing: lessons learned and future challenges
Over the past years, molecular testing for genetic diseases has rapidly moved from the laboratory into medical practice. In this process, issues of quality require adequate attention. The regular organization of external quality assessment (EQA) schemes (also named proficiency testing) has shown that quality assurance is essential in order to minimize errors in genetic service. EQA programs have been implemented in a many countries at different scales (regional, national, multinational, or large international level). As EQA schemes are important tools for education and performance monitoring of participating laboratories, the observation that different organizations have initiated the organization of such schemes is encouraging. Consequently, laboratories need to select the most appropriate EQA scheme(s) to which they should participate. National schemes may be advantageous in including samples with region-specific mutations and reporting in the national language. Large international schemes are more cost-efficiently organized, provide opportunities to participate for laboratories in countries lacking national schemes, and allow organizers to assess overall quality parameters in genetic laboratories at a large scale. The importance of organizing schemes at different levels will be further discussed and suggestions on how to harmonize different EQA schemes will be presented. The Cystic Fibrosis schemes organized by the European CF Network will be used to exemplify lessons learned over the years. This scheme runs for more than 10 years with up to 240 participants worldwide, and demonstrated that technical laboratory performance improved over time. In addition, the review for content and interpretation accuracy of reports that are being sent to referral physicians showed considerable variation in the reporting of laboratory results. Over the years, the scheme revealed improvements in the reporting of specific aspects of patient and technical information.