Inter-rater reliability assessment for the new-born screening quality assurance

Introduction: To ensure the quality of the new-born screening (NBS), our laboratory reviewed the analytical procedure to detect subjective steps that may represent a risk to the patient. Two subjective activities were identified in the extra-analytical phases: the classification of dried blood spots (DBS) according to their quality and the assignment of haemoglobin patterns. To keep these activities under control, inter-rater studies were implemented. This study aimed to evaluate the inter-rater reliability and the effectiveness of the measures taken to improve the agreement betwe-en observers, to assure NBS results' quality. Materials and methods: Dried blood spots specimens were used for the inter-rater studies. Ten studies were performed to assess DBS quality cla-ssification, and four to assess the assignment of haemoglobin patterns. Krippendorff's alpha test was used to estimate inter-rater reliability. Causes were investigated when alpha values were below 0.80. Results: For both activities, the reliability obtained in the first studies was inadequate. After investigation, we detected that the criterion to classify a DBS as scant was not consolidated, and also a lack of consensus on whether or not to report Bart's haemoglobin depending on its percentage. Alpha estimates became higher once the training was reinforced and a consensus about the appropriate criteria to be applied was reached. Conclusion: Inter-rater reliability assessment helped us to ensure the quality of subjective activities that could add variability to NBS results. Furthermore, the evolution of the value over time allowed us to the effectiveness of the measures

Automated summary

This study assessed the inter-rater reliability of subjective activities during new-born screening and implemented measures to improve agreement between observers. The results showed that consistency improved after establishing appropriate evaluation criteria and reinforcing training.