Corrective Actions Taken on Cases Misclassified as Confirmed COVID-19 Infections

Name and Constituency of Member of Parliament
Miss Cheng Li Hui
MP for Tampines GRC

Question No. 127

To ask the Minister for Health (a) how did it occur that 41 cases were wrongly classified as confirmed COVID-19 infections; (b) what were the corrective and public health actions that had been taken in the management of these cases including follow-ups with the affected individuals; and (c) how can occurrences of such misclassification be prevented in the future.

Answer

1.             Of the 41 cases that were classified initially as confirmed COVID-19 cases, most were due to administrative errors such as wrongly recorded or duplicated entries by laboratories. Eight were subsequently reclassified as non-cases following laboratory investigations and clinicians’ assessment. Corrective action had been taken early in the management of all these cases to ensure that they were isolated appropriately from other COVID-19 patients. Following the re-classifications, MOH had also rescinded any active quarantine orders of their close contacts.

2.          All clinical laboratories approved to provide COVID-19 testing are licensed and subject to compliance with the Private Hospitals and Medical Clinics (PHMC) Act. Licensees are required to ensure that they have the relevant resources, competencies and processes to conduct these tests in an accurate, safe and timely manner. Where the administrative errors arise from laboratory processes, the licensees are required to put in place corrective actions, which include additional counterchecks, re-training of staff and IT integration, to ensure that similar errors will not recur.

3.              Testing errors may also arise due to technical limitations inherent in the sensitivity and specificity of diagnostic tests.[1] Some results may be affected by other infections present in the person.MOH works closely with laboratory and clinical experts to review cases with borderline results and conduct thorough investigations, including repeat testing and review of the relevant clinical history and epidemiology. Such cases may subsequently be re-classified as non-cases. As a precautionary measure, MOH will classify them initially as positive cases and commence public health measures such as contact tracing and placing close contacts under quarantine while investigations are ongoing for such cases. Collectively, these measures will help to reduce the incidents of errors in testing results while allowing public health actions to be taken early to prevent further transmission of infection.

[1] In medical diagnosis, test sensitivity is the ability of a test to correctly identify those with the disease (true positive rate), whereas test specificity is the ability of the test to correctly identify those without the disease (true negative rate).