Point-of-care testing in primary healthcare: a scoring system to determine the frequency of performing internal quality control

Abstract

Objectives: Internal quality control (IQC) plays an important role in quality assurance in laboratory medicine. However, there is no universal consensus or guideline on when and how IQC should be analyzed on point-of-care testing (POCT) devices. The aim of this study was to develop a scoring system to determine how often IQC should be analyzed in primary healthcare on the various POCT devices. Methods: Based on a systematic literature review and a thorough process involving the whole Noklus, a nationwide POC organization, a scoring system for when to analyze IQC was developed. Four factors were considered to significantly impact IQC frequency: The importance of the analyte in diagnosing and monitoring patients, type of POCT device, user-friendliness, and number of patient samples. For each POCT device, the first three factors were given a score, and the sum of the scores determined the general recommended IQC frequency. The number of patient samples determined whether and how to adjust these frequencies in each individual general practice. Results: The scoring system was applied to 17 analytes and 134 different POCT devices (153 analyte-device combinations). Most of the devices analyzing high-risk analytes (71 out of 74) obtained daily or weekly IQC frequency. For example, all blood-cell counters and all glucose meters should undergo IQC daily and weekly, respectively. Conclusions: This study presents a consensus-based scoring system for differentiated and device-specific recommendations for IQC frequency on POCT devices in primary healthcare. The scoring system can easily be adopted to other local environments and is easy to use.